CAD-RADS™ 2.0 - 2022 Coronary Artery Disease Reporting Practice Guidelines PDF

Journal of Cardiovascular Computed Tomography 16 (2022) 536–557 Contents lists available at ScienceDirect Journal of Cardiovascular Computed Tomography...

Journal of Cardiovascular Computed Tomography 16 (2022) 536–557 Contents lists available at ScienceDirect Journal of Cardiovascular Computed Tomography journal homepage: www.JournalofCardiovascularCT.com Practice guidelines CAD-RADS™ 2.0 - 2022 Coronary Artery Disease-Reporting and Data System An Expert Consensus Document of the Society of Cardiovascular Computed Tomography (SCCT), the American College of Cardiology (ACC), the American College of Radiology (ACR), and the North America Society of Cardiovascular Imaging (NASCI) Ricardo C. Cury a, *, Jonathon Leipsic b, Suhny Abbara c, Stephan Achenbach d, Daniel Berman e, Marcio Bittencourt f, Matthew Budoff g, Kavitha Chinnaiyan h, Andrew D. Choi i, Brian Ghoshhajra j, Jill Jacobs k, Lynne Koweek l, John Lesser m, Christopher Maroules n, Geoffrey D. Rubin o, Frank J. Rybicki p, Leslee J. Shaw q, Michelle C. Williams r, Eric Williamson s, Charles S. White t, Todd C. Villines u, Ron Blankstein v a Miami Cardiac and Vascular Institute and Baptist Health of South Florida, Miami FL, USA b Department of Radiology, University of British Columbia, Vancouver, BC, Canada c Department of Radiology, UT Southwestern Medical Center, Dallas, TX, USA d Friedrich-Alexander-Universit€ at, Department of Cardiology, Erlangen, Germany e Cedars-Sinai Medical Center, Los Angeles, CA, USA f Division of Cardiology, University of Pittsburgh, Pittsburgh, PA, USA g David Geffen School of Medicine, UCLA, Los Angeles, CA, USA h Beaumont Hospital, Royal Oak, MI, USA i The George Washington University School of Medicine, Washington, DC, USA j Department of Radiology, Massachusetts General Hospital, Boston, MA, USA k NYU Langone Medical Center, New York, NY, USA l Department of Radiology, Duke University, Durham, NC, USA m Division of Cardiology, Minneapolis Heart Institute, Minneapolis, MN, USA n Department of Radiology, Naval Medical Center, Portsmouth, VA, USA o Department of Medical Imaging, University of Arizona, Tucson, AZ, USA p Department of Radiology, University of Cincinnati College of Medicine, Cincinnati, OH, USA q Icahn School of Medicine at Mount Sinai, New York, NY, USA r University of Edinburgh, Edinburgh, UK s Department of Radiology, Mayo Clinic, Rochester, MN, USA t University of Maryland, College Park, MD, USA u Division of Cardiology, University of Virginia Health System, Charlottesville, VA, USA v Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA A R T I C L E I N F O A B S T R A C T Keywords: Coronary Artery Disease Reporting and Data System (CAD-RADS) was created to standardize reporting system for Coronary artery disease patients undergoing coronary CT angiography (CCTA) and to guide possible next steps in patient management. Coronary CTA The goal of this updated 2022 CAD-RADS 2.0 is to improve the initial reporting system for CCTA by considering CAD-RADS new technical developments in Cardiac CT, including data from recent clinical trials and new clinical guidelines. Reporting and data system The updated CAD-RADS classification will follow an established framework of stenosis, plaque burden, and Stenosis severity modifiers, which will include assessment of lesion-specific ischemia using CT fractional-flow-reserve (CT-FFR) or Report standardization terminology Plaque burden myocardial CT perfusion (CTP), when performed. Similar to the method used in the original CAD-RADS version, Ischemia the determinant for stenosis severity classification will be the most severe coronary artery luminal stenosis on a per-patient basis, ranging from CAD-RADS 0 (zero) for absence of any plaque or stenosis to CAD-RADS 5 indi- cating the presence of at least one totally occluded coronary artery. Given the increasing data supporting the prognostic relevance of coronary plaque burden, this document will provide various methods to estimate and report total plaque burden. The addition of P1 to P4 descriptors are used to denote increasing categories of plaque *Corresponding author. Miami Cardiac and Vascular Institute, Baptist Health of South Florida, Florida International University, 8900 N. Kendall Drive, Miami, FL 33176, USA. E-mail addresses: [email protected] (R.C. Cury), [email protected] (R. Blankstein). https://doi.org/10.1016/j.jcct.2022.07.002 Received 29 January 2022; Received in revised form 10 March 2022; Accepted 2 July 2022 Available online 8 July 2022 1934-5925/© 2022 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved. 2022 CAD-RADS Journal of Cardiovascular Computed Tomography 16 (2022) 536–557 burden. The main goal of CAD-RADS, which should always be interpreted together with the impression found in the report, remains to facilitate communication of test results with referring physicians along with suggestions for subsequent patient management. In addition, CAD-RADS will continue to provide a framework of standardization that may benefit education, research, peer-review, artificial intelligence development, clinical trial design, pop- ulation health and quality assurance with the ultimate goal of improving patient care. 2. Clinical value of CAD-RADS and coronary CT angiography Abbreviations More than 50 publications have further validated specific aspects of CAD-RADS since its original publication in 201614 Fig. 1. The CAD-RADS CAD coronary artery disease classification has been shown to accurately predict major adverse car- CAD-RADS coronary artery disease reporting and data system diovascular events, defined as unstable angina, myocardial infarction, or CAC coronary artery calcium death, in patients with stable chest pain with superior performance when CCTA coronary CT angiography compared with traditional risk factors, other risk stratification scores, the CT-FFR computed tomography fractional flow reserve Coronary Artery Calcium Score (CAC) and the earlier SCCT coronary CTP computed tomography perfusion stenosis scoring system.15–19 CAD-RADS has also been demonstrated to HRP high-risk plaque correlate with the degree of stenosis measured by invasive coronary ICA invasive coronary angiography angiography (ICA) with high diagnostic accuracy.20,21 Recent publica- PCI percutaneous coronary intervention tions have highlighted that adoption of CAD-RADS in clinical practice SIS segment involvement score results in reduced downstream testing and cardiology referral rates in patients with non-obstructive coronary artery disease22 and has a favorable impact on medical therapy and systolic blood pressure con- trol.23 Finally, recent studies have validated the performance of deep 1. Introduction learning algorithms for the evaluation of CAD-RADS classification on CCTA.24 Coronary CT Angiography (CCTA) has undergone significant tech- There has been widespread adoption of CAD-RADS in clinical nical advancements and clinical validation in the last decade, and several practice with most sites in the United States and around the world professional societies have issued guidelines, expert consensus docu- using this classification for reporting CCTA on a routine basis. Overall, ments, and Appropriateness Criteria for CCTA.1–11 Training physicians available research suggests that CAD-RADS offers a clinically useful and technologists in image acquisition and interpretation is essential for and appropriate categorization of coronary artery disease with high fostering quality.12 Such training should also include an approach to diagnostic accuracy when compared with invasive angiography, with standardized reporting in order to decrease variability among practi- robust prognostic value and a beneficial impact on medical tioners and ensure that test results are appropriately used in patient management. management decisions. Since the publication of the original CAD-RADS classification, several The purpose of this document is to update the first version of the CAD- prospective trials have provided evidence supporting the clinical utility RADS13 standardized classification of coronary artery disease for patients of CCTA and the relevance of CT findings among patients with suspected undergoing CCTA that was originally published in 2016 in order to stable coronary artery disease. They include the PROMISE25 and SCO- include additional features such as plaque burden and ischemia, and to T-HEART26 trials, which demonstrated that CCTA is clinically useful as incorporate evidence from recent clinical trials as well as new clinical an alternative to functional testing (PROMISE) or in addition to standard practice guidelines. The updated 2022 CAD-RADS 2.0 classification will of care (SCOT-HEART). Based on these trials and multiple registries, the follow a framework of stenosis, plaque burden and modifiers, with the prognostic value of the CAD-RADS classification has been confirmed, option to also include ischemia evaluation by CT fractional-flow-reserve demonstrating that higher CAD-RADS scores were associated with (CT-FFR) or myocardial CT perfusion (CTP), if performed. As in the increased risks of fatal and non-fatal MI.15–17 original version, the most severe coronary artery luminal stenosis defined Moreover, several large randomized trials (CT-STAT, ACRIN-PA, on a per-patient basis will be the central component of assessment and ROMICAT II, CT-COMPARE) have compared CCTA to the current stan- will provide the numeric descriptor. In addition, methods to estimate, dard of care in patients with acute chest pain27–30. Complemented by real quantify and report overall plaque burden will be provided. Collectively, world implementation data,31–33 they consistently demonstrated the the goal of these additions is intended to enhance patient management safety of discharging patients from the emergency department based on a decisions following CCTA. negative CCTA, resulting in guidelines supporting the use of CCTA in low The main goal of CAD-RADS remains to standardize reporting of to intermediate risk patients presenting with acute chest pain to the CCTA results and to facilitate communication of test results to refer- emergency department.34 ring physicians along with suggestions for subsequent patient man- CCTA is now considered a first-line test (Class I) for use in acute and agement. Importantly, CAD-RADS should not be viewed as a substitute chronic coronary syndromes by the European Society of Cardiology,11 for the impression section of the report provided by the reading NICE guideline10 and by the new American College of Cardiology and physician. CAD-RADS provides a complementary assessment and American Heart Association Chest Pain Guideline,35 particularly in should always be interpreted in conjunction with the more detailed symptomatic patients with stable symptoms and intermediate or and patient-specific information found in the report and the impres- high pre-test probability of obstructive coronary artery disease, or among sion, particularly because the report may provide more specific in- intermediate-risk acute chest pain patients. Moreover, there have been formation regarding the location and extent of coronary plaque and numerous advances in the detection and quantification, understanding of stenosis. Furthermore, the clinical management suggestions provided atherosclerotic plaque burden by CCTA, as well as a better understanding by CAD-RADS should not replace clinical judgment, particularly as of the clinical implications of various CCTA findings.36 there are many patient-specific factors that may influence clinical Despite the robust evidence base supporting the use of CCTA in pa- management. tients with acute and stable chest pain, there is insufficient prospective 537 2022 CAD-RADS Journal of Cardiovascular Computed Tomography 16 (2022) 536–557 Fig. 1. Timeline plots of total quarterly PubMed citations resulting from the search “CAD-RADS” [Title/Abstract] OR “CADRADS” [Title/Abstract]. The date of the search was January 25, 2021. Permission received63 Radiol Cardiothorac Imaging. 2021 Jun; 3 (3): e210016. randomized clinical trial data to support the optimal clinical management Table 2 strategy following CCTA. Accordingly, the CAD-RADS classification is an Different methods to categorize the overall amount of coronary plaque. expert consensus document. As such, the recommendations provided in Overall amount CAC SIS* Visual* this document are based on the available research data from clinical trials of coronary plaque as well as on broad expert consensus. This includes the suggested cate- P1 Mild 1–100 2 1-2 vessels with mild amount of gories for reporting and the recommendations for further patient plaque P2 Moderate 101–300 3–4 1 -2 vessels with moderate amount; 3 vessels with mild Table 1 amount of plaque Grading scale for stenosis severity, plaque burden and ischemia. P3 Severe 301–999 5–7 3 vessels with moderate amount; 1 Degree of luminal Terminology vessel with severe amount of diameter stenosis plaque 0% No visible stenosis P4 Extensive >1000 8 2-3 vessels with severe amount of 1–24% Minimal stenosis plaque 25–49% Mild stenosis 50–69% Moderate stenosis Note: categories may not always correspond across different scores; if discrepant 70–99% Severe stenosis use CAC ¼ Coronary Artery Calcium or Total plaque burden quantification, if 100% Occluded available. Grading Scale for SIS ¼ Segment Involvement Score. plaque burden: * Please note that CAD-RADS 0 denotes absence of stenosis or plaque, therefore Terminology Overall plaque burden P0 is not required as a classification. * As there is currently no one single method that should be used to identify the P1 Mild amount of plaque P2 Moderate amount of plaque overall amount of plaque, CAD-RADS recommends that imagers select the P3 Severe amount of plaque technique which is considered most appropriate at a given institution. P4 Extensive amount of plaque * see examples in Figs. 2 to 6. Grading scale for Ischemia detection: Terminology Meaning Table 3 Modifier I Indicates that CT Ischemia test was performed either with Examples of non-atherosclerotic causes of coronary abnormalities to be included CT-FFR or myocardial CTP in Modifier “E” ¼ Exceptions. Please note that this is not a comprehensive list. Iþ Indicates that CT-FFR or CTP demonstrates lesion-specific Coronary dissection ischemia or reversible perfusion defect Anomalous origin of the coronary arteries I- Indicates that CT-FFR or CTP is negative for lesion specific Coronary artery aneurysm or pseudoaneurysm ischemia or reversible ischemiaa Vasculitis I Indicates that CT-FFR or CTP is borderline Coronary artery fistula a Extrinsic coronary artery compression Patients with prior myocardial infarction and fixed perfusion defects without Arterio-venous malformation evidence of myocardial ischemia by CTP would be classified as I-. The presence of Other causes myocardial infarction should be documented in the impression of the report. 538  2022 CAD-RADS Table 4 CAD-RADS Reporting and Data System for patients presenting with stable chest pain. Category Degree of maximal Interpretation Further Cardiac Investigation Management considerations coronary stenosis CAD-RADS 0 0% Absence of CADa None - Reassurance. Consider non-atherosclerotic causes of symptoms (No plaque or stenosis) CAD-RADS 1 1–24% Minimal non-obstructive CADb None - Consider non-atherosclerotic causes of symptoms (Minimal stenosis or plaque with no stenosisb) - P1: Consider risk factor modification and preventive pharmacotherapy - P2: Risk factor modification and preventive pharmacotherapy - P3 or P4: Aggressive risk factor modification and preventive pharmacotherapy CAD-RADS 2 25–49% Mild non-obstructive CAD None - Consider non-atherosclerotic causes of symptoms (Mild stenosis) - P1 or P2: Risk factor modification and preventive pharmacotherapy - P3 or P4: Aggressive risk factor modification and preventive pharmacotherapy CAD-RADS 3 50–69% Moderate stenosis Consider functional assessmentc - P1, P2, P3 or P4: Aggressive risk factor modification and preventive (Moderate stenosis) pharmacotherapy - Other treatments (including anti-anginal therapy) should be considered per guideline directed cared - When modifier Iþ, consider ICA, especially if frequent symptoms persist after guideline-directed medical therapy 539 CAD-RADS 4 A - 70–99% stenosis Severe stenosis A: Consider ICAe or functional assessment P1, P2, P3 or P4: Aggressive risk factor modification and preventive or B: ICA is recommended pharmacotherapy. B - Left main 50% or 3- vessel - Other treatments (including anti-anginal therapy and options of obstructive (70%) disease revascularization) should be considered per guideline directed carec CAD-RADS 5 100% Total coronary occlusion or sub-total occlusion Consider ICA, functional and/or P1, P2, P3 or P4: Aggressive risk factor modification and preventive (total occlusion) viability assessment pharmacotherapy. Journal of Cardiovascular Computed Tomography 16 (2022) 536–557 - Other treatments (including anti-anginal therapy and options of revascularization) should be considered per guideline directed carec CAD-RADS N Non-diagnostic study Obstructive CAD cannot be excluded Additional/alternative evaluation may be needed The CAD-RADS classification should be applied on a per-patient basis for the clinically most relevant (usually highest-grade) stenosis. All vessels greater than 1.5mm in diameter should be graded for stenosis severity. CAD-RADS will not apply for smaller vessels (90%), high-risk plaque features or I þ (presence of lesion-specific ischemia on CT FFR or perfusion defects by CTP) or concordant ischemia by other stress tests and a candidate for revascularization. It should be clarified that benefit of revascularization should be confined to patients with persistent symptoms despite optimal medical therapy.  2022 CAD-RADS Table 5 CAD-RADS Reporting and Data System for patients presenting with acute chest pain. Category Degree of maximal Interpretation Cardiac Investigation Management considerations coronary stenosis CAD-RADS 0 0% ACS highly unlikely - No further evaluation of ACS is required - If Tn (þ) consider - Reassurance. other sources of increased troponin (See Table 9) CAD-RADS 1 1–24%a ACS unlikely - No further evaluation of ACS is required - P1 or P2: Referral for outpatient follow-up for risk factor modification and - If Tn (þ) consider other sources of increased troponin (See preventive pharmacotherapy. Table 9) - P3 or P4: Referral for outpatient follow-up for aggressive risk factor modification and preventive pharmacotherapy CAD-RADS 2 25–49% ACS less likely - No further evaluation of ACS is required - P1 or P2: Referral for outpatient follow-up for risk factor modification and - If clinical suspicion of ACS is high, Tn (þ) or HRP features, preventive pharmacotherapy. consider hospital admission with cardiology consultation. - P3 or P4: Referral for outpatient follow-up for aggressive risk factor modification and preventive pharmacotherapy CAD-RADS 3 50–69% ACS possible - Consider hospital admission with cardiology consultation. - P1, P2, P3 or P4: Preventive management, including aggressive preventive - Consider functional assessmentb pharmacotherapy. Other treatments, including anti-anginal therapies, should be considered per guideline directed carec. - When modifier Iþ, consider ICA. 540 CAD-RADS 4 A - 70–99% or ACS likely - Hospital admission with cardiology consultation. - P1, P2, P3 or P4: Preventive management, including aggressive preventive B - Left main A Consider ICAd or functional assessment pharmacotherapy. 50% or 3-VD B ICA is recommended - Other treatments, including anti-anginal therapies and options of revasculari- zation, should be considered per guideline directed carec CAD-RADS 5 100% (Total occlusion) ACS very likely - Hospital admission with cardiology consultation. Expedited - P1, P2, P3 or P4: Preventive management, including aggressive preventive ICA and revascularization if suspected acute occlusione pharmacotherapy. - Other treatments (including anti-anginal therapies and options of revasculari- Journal of Cardiovascular Computed Tomography 16 (2022) 536–557 zation) should be considered per guideline directed carec CAD-RADS N Non-diagnostic study ACS cannot be excluded Additional or alternative evaluation for ACS is needed The CAD-RADS classification should be applied on a per-patient basis for the clinically most relevant (usually highest-grade) stenosis. All vessels greater than 1.5mm in diameter should be graded for stenosis severity. CAD-RADS will not apply for smaller vessels (70%). If a left main coronary artery stenosis at least greater than 50% is suspected or if the examination demonstrates three-vessel obstructive disease, then further evaluation with invasive angiography and possible revascularization is recom- mended. For this reason, CAD RADS 4 is sub-divided into A and B: CAD RADS 4A - This category indicates the case of a single vessel or two vessels demonstrating severe stenosis (70–99%). Further evaluation with ICA or functional imaging, including CT-FFR, CTP and stress testing Fig. 3. CAD-RADS 1/P1 - Minimal coronary stenosis (1–24%). Plaque Burden – (ETT, stress echocardiogram, SPECT, PET or Cardiac MRI) or invasive P1: Mild amount of plaque burden. FFR is usually recommended depending on location, extent and severity 541 2022 CAD-RADS Journal of Cardiovascular Computed Tomography 16 (2022) 536–557 Fig. 4. CAD-RADS 2/P2 – Mild coronary stenosis (25–49%). Plaque Burden – P2: Moderate amount of plaque burden. Fig. 5. CAD RADS 1/P3 - Plaque Burden – P3: Severe amount of plaque burden – SIS ¼ 7, Extensive amount of diffuse plaque and minimal coronary stenosis. of the lesion(s), and clinical characteristics, such as angina severity and CAD RADS 4B - This indicates the presence of a left main stenosis of the use of current guideline-directed medical therapies. It should be at least 50% or three-vessel obstructive disease (>70%). Further evalu- clarified that the benefit of revascularization is confined to patients with ation with ICA and possible revascularization is usually recommended, frequent symptoms despite optimal medical therapy. Other important particularly for patients with frequent symptoms despite optimal medical considerations such as the presence of very-high-grade coronary stenosis therapy. (>90%) or high-risk plaque features as well as evidence of lesion-specific The clinical relevance of CAD-RADS 5 (total coronary occlusion) varies ischemia by FFR-CT or perfusion defects by myocardial CTP may favor widely depending on the clinical context. It may be acute or chronic, and, the use of ICA as the next step in patient care, if revascularization is being in the context of chronic occlusion, factors such as lesion length, calcifi- considered. Persistent anginal symptoms despite medical therapy should cation particularly at the proximal aspect, tortuosity and degree of col- also favor the use of ICA. lateralization may be of relevance for management decisions (Fig. 11). 542 2022 CAD-RADS Journal of Cardiovascular Computed Tomography 16 (2022) 536–557 Fig. 6. CAD-RADS 4B/P4. Plaque Burden – P4: Three vessel severe coronary stenosis with extensive amount of plaque burden – CAC ¼ 3607. Fig. 7. CAD-RADS 4A/P1. Focal non-calcified plaque in the mid LAD (yellow arrow) with 70–99% severe coronary stenosis and mild amount of focal non-calcified plaque burden (P1) (left). Invasive coronary angiography confirming 70–99% stenosis in the mid LAD (yellow arrow, right). (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.) 543 2022 CAD-RADS Journal of Cardiovascular Computed Tomography 16 (2022) 536–557 Fig. 8. CAD-RADS 4B/P2. Three-vessel obstructive disease (>70% stenosis), including in 70–99% stenosis of the proximal RCA (left), 70–99% stenosis of the proximal LAD (middle) and 70–99% stenosis of the mid LCX (right) and moderate amount of non-calcified plaque burden (P2). Overall, a similar framework (Table 5) is used for patients with acute to local practice norms. However, it is important to emphasize that when chest pain with other considerations including persistent clinical symp- multiple different approaches can be performed to assess plaque burden, toms, troponin levels, EKG changes and high-risk plaque features leading the most severe plaque assessment for the study should be used. It is also to hospital admission and cardiology consultation for further work-up important to highlight that the P recommendations based on CAC or SIS and management. is supported by prior evidence36 and may be more reproducible. The methods for reporting total coronary plaque burden include the 3.2. Plaque burden sub-classification following: 3.2.1. Overall amount of coronary plaque (“P”) (1) CAC testing - CAC provides a reproducible, and accurate method There are substantial data demonstrating that the overall amount of to quantify the amount of calcified plaque burden. The total CAC coronary plaque by CCTA has strong association with incident coronary score is an established surrogate of overall coronary plaque heart disease events36–40 and such information may offer stronger burden. When performed as part of a CCTA exam, CAC testing prognostic value than merely the presence or absence of anatomical (most commonly quantified according to the Agatston method) stenosis and clinical variables.41 Indeed, the ability to detect the presence can be used to identify the overall amount of plaque (Table 2). and amount of plaque by CCTA is a unique attribute of cardiac CT when However, calcium score should not be used in isolation and should compared with other non-invasive tests. be combined with at least a qualitative assessment of total plaque The updated version of CAD-RADS classification incorporates the burden (calcified and non-calcified) to ensure that non-calcified designation “P” with categories ranging from P1 to P4 to categorize the plaque is also accounted. Therefore, the plaque burden and “P” overall amount of plaque as mild, moderate, severe or extensive on a per- category based on Calcium score will stay the same (if no non- patient basis (Table 2). Please note that CAD-RADS 0 denotes absence of calcified plaque is seen) or may increase after incorporating in- stenosis or plaque, therefore P0 is not required as a classification. formation on the total burden of non-calcified plaque. Moreover, Importantly, there is currently no single method that is used to quantify institutional protocols may not always include CAC testing as a the overall amount of plaque and thus the CAD-RADS classification en- component of CCTA and importantly, the CAC score alone lacks ables imagers to select the technique which is most relevant for each the important quantification of non-calcified plaque burden. CCTA study at a given institution. Assessment of plaque burden within an (2) Segment involvement score (SIS) - the segment involvement individual patient may vary substantially depending upon the method score can easily be calculated from CCTA by assigning a score of 1 applied. Thus, it is recommended that imagers select the technique which for each of the 16 coronary segments with any detectable plaque is considered most appropriate for the individual patient and according (highest possible score ¼ 16).36 This method provides an estimate 544 2022 CAD-RADS Journal of Cardiovascular Computed Tomography 16 (2022) 536–557 Fig. 9. CAD-RADS 4B/P3. Distal left main stenosis with circumferential calcified plaque resulting in >50% stenosis (arrow) and severe amount of plaque (P3 - Calcium Score ¼ 640). Upper left panel: oblique longitudinal plane of the left main coronary artery. Lower left panel – cross-sectional slice of the distal left main coronary artery. Figures on the right - Invasive coronary angiography confirming focal severe stenosis in the distal left main coronary artery. of the overall extent of coronary plaque, and there are several recognition that different methods are used by different centers. More- studies demonstrating that a larger SIS is associated with higher over, providing flexible options to estimate the overall amount of plaque rates of cardiovascular death or MI.38,41 is important to facilitate routine assessment of plaque burden as part of (3) Visual estimate of overall plaque burden - this method is based the clinical reading. Ultimately, gaining wider adoption by CCTA pro- on a qualitative estimate of the amount of calcified and non- grams to report the overall amount of plaque may be more important calcified plaque in each coronary vessel, and then providing an than reliance upon a particular technique. Moreover, the CAD-RADS assessment of overall plaque burden (Table 2; Examples recommendations for patient management using plaque assessment are Figs. 2–6). mostly based on expert opinion (i.e. the number of studies that have (4) Quantitative Assessment of Total Coronary Plaque - The evaluated the efficacy of various therapies based on different thresholds writing group discussed various quantitative approaches that are of atherosclerosis is limited). As such, there are no absolute consensus available to quantify total coronary plaque volume on CCTA.42 thresholds based on these categories, but rather a framework whereby While there are numerous important emerging techniques for more aggressive therapies are suggested for individuals that have a performing a quantitative and reproducible assessment of total higher plaque burden (See Tables 2, 4 and 5). plaque burden and plaque type beyond visual assessment alone, these techniques are not widely available and not routinely per- 3.3. Modifiers formed as part of clinical CCTA interpretation. In addition, most of the available techniques are time and labor intensive, which CAD-RADS categories can be complemented by modifiers to indicate inhibit incorporation into routine clinical interpretation. These that a study is not fully evaluable or non-diagnostic (N), or to indicate the techniques require further validation against other techniques, presence of stents (S), grafts (G), and high-risk plaque (HRP). In this including intravascular ultrasound, optical coherence tomography, updated CAD-RADS version, the panel has added two new modifiers: and histology. In addition, clinical registries and multi-center trials ischemia (I) and exceptions (E). In addition, the term “vulnerable plaque will need to validate the reproducibility of different approaches, as (V)” has now been replaced with “high risk plaque (HRP)” to be well as establish sex and age reference ranges that can enhance risk consistent with evolving terminology. assessment. The writing group anticipates that future iterations of CAD-RADS will incorporate novel techniques for plaque quantifi- 3.3.1. Modifier N – non-diagnostic study cation as these become more developed and widely used. “N” can be used as a modifier or as a CAD-RADS category, depending on context. If the study is not fully diagnostic, due to motion artifacts, The writing group recognizes that providing various different options calcium blooming, metal artifacts or other types of artifacts, (i.e. not all to estimate overall plaque burden may lower the reproducibility of such segments >1.5 mm diameter can be interpreted with confidence) and a an assessment. However, it is important to offer different options in stenosis 50% is present in a diagnostic segment (CAD-RADS  3), the 545 2022 CAD-RADS Journal of Cardiovascular Computed Tomography 16 (2022) 536–557 Fig. 10. CAD-RADS 5/P3. Two examples of 5mm thick MIPs CCTA cases coded as CAD-RADS 5. Left: Focal, non-calcified occlusion of the proximal RCA (arrow) and severe amount of plaque (P3). Right: Total occlusion of the proximal LCX (arrow) and extensive amount of plaque (P4). A small focus of “orphan” calcium along the distal LCX supports the diagnosis of chronic total occlusion. Fig. 11. CAD-RADS N/P2. Motion artifacts obscuring the left main, LAD and LCX arteries, which renders these segments non-diagnostic (left) and moderate amount of plaque (P2 - Calcium Score ¼ 247). Motion artifacts in the mid RCA (right) with calcified plaque. 546 2022 CAD-RADS Journal of Cardiovascular Computed Tomography 16 (2022) 536–557 Fig. 12. CAD-RADS 3/P2/N. Motion artifact obscuring the mid RCA (left, arrow), which renders this segment non-diagnostic. There is also stenosis of the mid LAD with 50–69% luminal narrowing (right, arrow), qualifying this lesion as CAD RADS 3 and moderate amount of coronary plaque (P2). Although the mid RCA segment is non-diagnostic, the presence of suspected obstructive disease within the LAD should be coded as CAD RADS 3/P2/N. If the LAD lesion were mild (less than 50% diameter stenosis), and no other stenosis were identified, the patient would be coded as CAD RADS N. Fig. 13. CAD-RADS 4A/P3/S. In-stent stenosis of the proximal LAD with significant luminal narrowing (70–99% stenosis) and severe amount of coronary plaque (P3). Grading of in-stent stenosis should follow the grading of normal coronary arteries (0% stenosis, 1–24% stenosis, 25–49% stenosis, 50–69% stenosis, 70–99% stenosis, and >99% stenosis). In this case, severe in-stent restenosis designates a CAD-RADS 4A lesion, which would be followed by category P3 for extensive plaque burden and the stent modifier “S” for the presence of stent. 547 2022 CAD-RADS Journal of Cardiovascular Computed Tomography 16 (2022) 536–557 Fig. 14. MODIFIER G. Coronary CTA demonstrating a patent left internal mammary artery to the LAD and patent saphenous vein grafts to the ramus intermedius and second obtuse marginal branch. No stenoses or luminal narrowing throughout the grafts (0% stenosis, left). Invasive coronary angiography demonstrating patent LIMA graft to the LAD (right). When evaluating coronary CTA of patients with bypass grafts, the native coronary artery segments proximal to the graft anastomoses should not be evaluated for purposes of CAD RADS coding. Only the grafts and the native coronary artery segments distal to and including the anastomosis should be evaluated for CAD RADS coding. most severe stenosis should be graded in addition to the modifier N. For management recommendations, so it does not matter whether the example, a patient with moderate stenosis (50–69%) in one segment and severe stenosis is in stented or non-stented vessel. Rather, the key issue one or more non-diagnostic segments and also moderate amount of is whether the patient has a severe stenosis and may be considered for plaque burden, should be graded as CAD-RADS 3/P2/N (Fig. 12) and not further work-up. Category P should also be added to indicate the CAD-RADS N, since further evaluation is needed, possibly with func- amount of plaque burden. tional imaging, and patient recommendations for anti-ischemic and preventive management apply. However, for a patient with at least one 3.3.3. Modifier G ¼ grafts - presence of coronary bypass grafts non-interpretable segment and no stenosis (zero), minimal (1–24%), or The modifier “G” indicates the presence of at least one coronary- no more than mild stenosis (25–49%) in interpretable segments, CAD- artery bypass graft (Fig. 14). A stenosis bypassed by a fully patent graft RADS N should be used since CCTA cannot reliably exclude a significant is not considered for the CAD-RADS classification. For example, if a pa- stenosis and cannot be used to guide patient management and hence, tient has a graft to LAD, with absence of significant stenosis in the graft, further evaluation is still needed. Category “P” should be used with distal anastomosis and run-off vessel, and demonstrates non-obstructive category or modifier “N”, if total coronary plaque assessment can be lesions (25–49%) in the LCX and RCA, in addition to the “expected” performed reliably. Category “N” should precede Category “P” in proximal LAD severe stenosis, and moderate plaque burden, the case replacement of the numerical stenosis assessment, if there is a non- would be classified as: CAD-RADS 2/P2/G. In the example of a patient interpretable coronary segment and no other coronary segment with with total occlusion of a saphenous vein graft (SVG) to the RCA, and a greater than 50% stenosis. On the other hand, the numerical stenosis patent LIMA to LAD and SVG to LCX, and severe plaque burden, the case category and category “P” will precede Modifier “N” if there is a stenosis would be classified as: CAD-RADS 5/P3/G. The interpretation is that a greater than 50% (CAD-RADS 3 or greater). total occlusion is present and further management or investigation may be considered. Total plaque burden should be assessed in both native 3.3.2. Modifier S ¼ stent - presence of coronary stents coronary arteries and by-pass grafts. A combined assessment should be The modifier “S” indicates the presence of at least one coronary considered for deciding on Category “P”. stent anywhere in the coronary system. For example, if a patient has a stent in the proximal left anterior descending coronary artery 3.3.4. High-risk plaque (HRP) features (previously “vulnerable plaque” [V]) (LAD) with no significant in-stent restenosis or occlusion and dem- Data from recent CCTA studies have described high-risk plaque onstrates mild non-obstructive disease (25–49%) in the left circumflex characteristics that are associated with a higher risk of future ACS as (LCX) and right coronary arteries (RCA), the CCTA would be classified well as lesion specific ischemia. Features originally described as indi- as: CAD-RADS 2/S. If a patient demonstrates significant in-stent cating HRP include positive remodeling, low-attenuation plaque, spotty restenosis of a stent in the proximal LAD, the study would be classi- calcification, and the napkin-ring sign.43–46 These plaque characteris- fied as: CAD-RADS 4A/S (Fig. 13). Similarly, a non-stenotic stent in tics are associated with intravascular ultrasound and histological fea- the LAD and a new severe stenosis in the RCA would be classified as tures of more advanced atherosclerotic plaque and thin cap CAD-RADS 4A/S. Finally, if a stent is non-evaluable, the study would fibroatheroma, which has the potential to develop to plaque ruptur- be classified as CAD-RADS N/S if there is no other stenosis greater e/thrombosis. However, the prevalence of these features on CCTA is than 50% in the coronary tree. Note: CAD-RADS was created to guide high (~30% of CCTA, with an even higher frequency in the presence of 548 2022 CAD-RADS Journal of Cardiovascular Computed Tomography 16 (2022) 536–557 Fig. 16. CAD-RADS 2/P2/HRP. Focal non-calcified plaque in the mid RCA with 25–49% diameter stenosis and overall moderate amount of total coronary pla- que. The plaque demonstrates two high risk features, low attenuation (1.1; and d) Low attenuation plaque, defined as non-calcified plaque with internal attenua- plaque with 50–69% diameter stenosis, excluding left main lesions) tion less than 30 HU. Please note that a combination of two or more high-risk should prompt consideration of more aggressive management than features is necessary to designate the plaque as high-risk for CAD-RADS. studies coded only with CAD-RADS 3, particularly in patients presenting 549 2022 CAD-RADS Journal of Cardiovascular Computed Tomography 16 (2022) 536–557 Table 6 to the emergency department with acute chest pain. This includes Interpretation of CT-FFR. If there is presence of abnormal CT-FFR as defined as a consideration of further testing with CT-FFR, CTP, other stress imaging, lesion-specific value  0.75 in a vessel large enough for PCI the designation of or invasive coronary angiography depending on the clinical symptoms, “Iþ” (I¼Ischemia) should be included. “I-” in the setting of a lesion-specific CT- EKG findings and biomarkers. However, management decisions should FFR >0.80. For values between 0.76 and 0.80 the modifier “Iþ/” is used and ultimately be made on an individual basis taking into consideration all decisions around ICA referral depend on lesion location, symptom severity and supporting clinical and laboratory data. delta CT-FFR. CCTA (Stenosis) CT-FFR Interpretation and 3.3.5. Modifier I ¼ ischemia: CT-FFR or CTP Considerations Historically, CCTA exclusively provided anatomical information CT-FFR may be used in coronary Abnormal CAD-RADS 3 or 4/I þ comprising luminal stenosis severity and atherosclerotic burden. Given stenosis ranging from 50 to (Iþ) Anatomical stenosis in one vessel the growing evidence regarding the critical importance of physiology to 90% to better define if a (0.75) with concordant lesion-specific stenosis is hemodynamically abnormal CT-FFR 0.75. guide decisions around coronary revascularization and the development significant (particularly CAD- Consider ICA for individuals of techniques enabling functional assessment of CCTA the writing group RADS 3 and 4A) likely to benefit from deemed it important to update the CAD-RADS reporting guidelines to CAD-RADS 3 - Moderate stenosis revascularization reflect this practice shift. The Modifier “I” indicates that an ischemia test CAD-RADS 4A - Severe stenosis has been performed (either CT-FFR or stress CTP). Normal (I-) CAD-RADS 3 or 4/I- Anatomical CAD-RADS 2 could be considered (>0.80) stenosis with lesion-specific CT- if proximal lesion and stenosis 3.3.5.1. Computed tomography - fractional-flow reserve (CT-FFR). CT-FFR FFR >0.80. Defer invasive 40%, including in the angiography and optimize was first introduced over a decade ago and allows for the computation presence of high-risk plaque of pressure across the coronary tree through the integration of ma- medical therapy. features Anatomical stenosis with lesion- chine learning for anatomical data extraction and computational fluid specific CT-FFR >0.80. At least dynamics. The technique has been shown to be accurate and demon- one vessel has a distal value  strates excellent agreement with invasive FFR.48 There is also growing 0.80, but this value does not appear to be associated with a clinical utility data across multiple healthcare systems documenting specific stenosis. Defer invasive the safety of deferral from catheterization in the setting of a negative angiography and optimize CT-FFR (>0.80), the improved catheterization lab efficiency (ICA) and medical therapy. increased risk associated with an CT-FFR 0.80.49 There is also Borderline CAD-RADS 3 or 4/I ±Anatomical growing evidence of the continuous rather than discrete nature of (Iþ/) stenosis in one vessel with physiology with increasing risk with lower CT-FFR values. Given the (0.76–0.80) borderline, grey-zone CT-FFR non-binary nature of CT-FFR, current clinical guidance emphasizes 0.76–0.80. that the CT-FFR value 1–2 cm distal to an area of coronary stenosis Consider invasive angiography should be considered to guide decisions around referral to invasive based on symptoms, lesion angiographic and revascularization.50 The lowest overall value along location, and trans-lesional pressure loss (>.12 significant the entire vessel may be informative but typically reflects total measured 1–2 cm proximal to a plaque burden and the ratio of coronary volume to mass, and hence stenosis – CT-FFR 1–2 cm distal reflects vascular health, as a result it can be used to inform medical to the stenosis) and for management but should not be used to guide catheterization labora- individuals likely to benefit from revascularization tory referral.51 Table 7 Interpretation of Stress Myocardial CT Perfusion. If there is presence of myocardial ischemia (reversible perfusion defect) or peri-infarct ischemia (perfusion defect during stress larger than rest perfusion defect), then the Modifier Iþ (I¼Ischemia) will be added to CAD-RADS. If no ischemia is detected or if there is presence of a prior fixed myocardial infarct, then the Modifier I- will be added to CAD-RADS. Modifier I indicates that the study is borderline for the presence of ischemia. CCTA (Stenosis) Stress CTP Rest CTP Interpretation Stress CTP may be used in coronary Perfusion defect (þ) Negative () Myocardial ischemia in a defined stenosis ranging from 50 to 90% to coronary territory better define if a stenosis is CAD-RADS 3 or 4/Iþ hemodynamically significant (particularly CAD-RADS 3 and 4A) CAD-RADS 3 - Moderate stenosis CAD-RADS 4A - Severe stenosis Perfusion defect (þ) Perfusion defect (þ) Myocardial infarct or no evidence of *CAD-RADS 2 could be considered if ischemia in a defined coronary proximal lesion and stenosis >40%, territory including in the presence of high- CAD-RADS 3 or 4/I- risk plaque features Perfusion defect (þ) Perfusion defect (þ) Peri-infarct ischemia in a defined coronary territory CAD-RADS 3 or 4/Iþ 550 2022 CAD-RADS Journal of Cardiovascular Computed Tomography 16 (2022) 536–557 Table 8 To that end, current evidence suggests possible ICA referral for a Summary of the main changes for 2022 CAD-RADS update when compared to the symptomatic patient in the setting of an appropriate clinical context for first version published in 2016. coronary revascularization and the designation of “Iþ” (positive ischemia) 2016 CAD-RADS 2022 CAD-RADS for a lesion-specific value  0.75 in a vessel large enough for percutaneous Stenosis grading CAD-RADS 0, 1, 2, 3, No change coronary intervention (PCI). Similarly, deferral of ICA would be approxi- 4A, 4B and 5 mate in the setting of a “I-” (negative ischemia) lesion-specific CT-FFR >0.80 (Table 6). For values between 0.76 and 0.80 the modifier “Iþ/¡” Plaque burden No systematic New CAD-RADS category grading (borderline or indeterminate value) is used and decisions around ICA grading classification scale for Plaque Burden ranging from P1 to P4 referral will further depend on lesion location, symptom severity and delta CT-FFR (trans-lesional gradient >0.12 considered significant) as measured Modifiers Four modifiers were Addition of two new modifiers: as the pressure loss from 1 to 2 cm proximal to 1–2 cm distal to a stenosis.52 introduced to modifier I (ischemia) and modifier complement the E (exceptions) and replacement of For lesions with an abnormal CT-FFR without a concordant anatomic CAD-RADS modifier V (vulnerable) with HRP lesion, the modifier “I-” should be described in case the reader is confident classification (high-risk plaque) that this is false-positive result by CT-FFR or “Iþ/¡” if it is indeterminate First: modifier N First: modifier N (non-diagnostic) and there is questionable interpretation of both findings. In multivessel (non-diagnostic) Second: modifier HRP (replaces Second: modifier S V) disease the physiologically significant lesion may not be the most (stent) Third: modifier Iþ (ischemia), I- anatomically severe. This needs to be contextualized and clarified in the Third: modifier G and I ± body of the report and impression. In case the CT-FFR study is (graft) Fourth: modifier S (stent) non-diagnostic, modifier N can also be applied to CT-FFR or CTP. Table 6 Fourth: modifier V Fifth: modifier G (graft) summarizes interpretation of CT-FFR. (vulnerability) Sixth: modifier E (exceptions) 3.3.5.2. Myocardial CT perfusion. Advancements in CT technology, in Table 9 particular the development of wide-area detectors with greater z-axis Potential sources of high-sensitivity troponin elevationa. coverage and dual-source CT, have improved functional assessment of Cardiac Myocardial infarction the myocardium using stress CTP. Myocardial CTP has been validated in Myocardial injury Myocarditis/myocardial inflammation patients with acute and chronic chest pain against modalities such as Infiltrative heart disease (amyloid, sarcoidosis) cardiac MRI, SPECT-MPI, invasive coronary angiography, invasive FFR Cardiomyopathy (e.g. stress cardiomyopathy) and cardiac biomarkers.53–55 Furthermore, a combined approach of Recent ablation/defibrillation myocardial CTP with coronary CTA has been shown to have better Vascular Pulmonary embolism/pulmonary hypertension diagnostic accuracy than CCTA alone in patients at intermediate-to-high Aortic dissection risk for coronary artery disease (CAD).56–58 Therefore, the Society of Cardiovascular Computed Tomography has provided resources to facili- Other Central nervous system pathology (e.g. stroke, seizure) Kidney disease tate clinical implementation of CTP.59 The addition of stress myocardial Chest wall trauma CTP to CCTA allows detection of hemodynamically significant stenosis in Rhabdomyolysis/myositis a single setting with the identification of reversible myocardial ischemia Chemotherapy correlating with the same territory in which a moderate or severe stenosis Metastatic disease Inherited conditions (e.g. muscular dystrophy) is suspected. Stress myocardial CTP also allows the exclusion of Carbon monoxide myocardial ischemia in moderate coronary stenosis (50–69%) or a sus- Infectious pected severe coronary stenosis (>70%) with dense calcified or mixed a Adapted based on Causes on Troponin Elevation and Associated Mortality in plaques, avoiding additional downstream testing. It also allows the Younger Patients.60 identification of fixed perfusion defects related to prior myocardial Fig. 17. CAD-RADS 3/P3/HRP/S. Example demonstrating a patent stent (S) in the proximal RCA (0% stenosis) with high-risk plaque (HRP) in the proximal LAD with thick MIP images resulting in 50–69% stenosis and overall severe amount of total coronary plaque burden (P3). In isolation, the proximal LAD lesion would be coded CAD RADS 3/P3/HRP. However, since CAD RADS is coded on a per-patient basis, and a RCA stent is present, this patient would be coded as CAD RADS 3/P3/S/HRP. 551 2022 CAD-RADS Journal of Cardiovascular Computed Tomography 16 (2022) 536–557 Fig. 18. Sample standardized reporting template for Coronary CTA incorporating CAD-RADS coding. 552 2022 CAD-RADS Journal of Cardiovascular Computed Tomography 16 (2022) 536–557 infarction. Table 7 describes the interpretation of stress CTP and how it is Table 11 incorporated with the different CAD-RADS categories. In the presence of 2022 CAD-RADS 2.0 Suggested Text for Recommendations Section of CCTA myocardial ischemia (reversible perfusion defect) or peri-infarct Reporting in Patients with Acute Chest Pain (See Table 5 for further detail). ischemia (perfusion defect during stress larger than rest perfusion Below intended to aid reporting based on specific CAD RADS categorization. defect), the Modifier “Iþ” should be added to CAD-RADS. If no ischemia Note: including information from footnotes in patient report is optional. is detected or if there is presence of a prior fixed myocardial infarct, the Stenosis Plaque Suggested Recommendation for Report Modifier “I-” will be added to CAD-RADS. The presence of myocardial CAD RADS 0 N/A  Reassurance. No further evaluation of ACS is infarct should be documented in the impression of the report and the required. Modifier “I” should be reserved exclusively to ischemia. The Modifier  If Tn (þ) consider other sources of increased troponin “Iþ/¡” indicates that the study is borderline or inconclusive for the CAD RADS 1 P1 or P2  No further evaluation of ACS is required. presence of ischemia. Similarly to the mismatch between CT-FFR and  If Tn (þ) consider other sources of increased CCTA results, an ischemic segment without a concordant anatomic troponin lesion, should be classified as modifier “I-” in case the reader is confident  Referral for outpatient follow-up for risk factor that this is a false-positive result by CTP or “Iþ/¡” if it is indeterminate modification and preventive pharmacotherapy. CAD RADS 1 P3 or P4  No further evaluation of ACS is required. and there is questionable and discrepant interpretation of both findings.  If Tn (þ) consider other sources of increased troponin  Referral for outpatient follow-up for aggressive risk factor modification and preventive Table 10 pharmacotherapy. 2022 CAD-RADS 2.0 Suggested Text for Recommendations Section of CCTA CAD RADS 2 P1 or P2  If clinical suspicion of ACS is high, Tn (þ) or high Reporting in Patients with Stable Chest Pain (See Table 4 for further detail). risk plaque (HRP) features, consider hospital Below intended to aid reporting based on specific CAD RADS categorization. admission with cardiology consultation. Note: including information from footnotes in patient report is optional.  If Tn (þ) consider other sources of increased troponin Stenosis Plaque Suggested Recommendation for Report  Referral for outpatient follow-up for risk factor CAD RADS 0 N/A  Reassurance. Consider non- modification and preventive pharmacotherapy, atherosclerotic causes of symptoms. CAD RADS 2 P3 or P4  If clinical suspicion of ACS is high, Tn (þ) or high CAD RADS 1 or CAD P1  Consider non-atherosclerotic causes of risk plaque (HRP) features, consider hospital RADS 2 symptoms. admission with cardiology consultation.  Consider risk factor modification and  If Tn (þ) consider other sources of increased preventive pharmacotherapy. troponin. P2  Consider non-atherosclerotic causes of  Referral for outpatient follow-up for aggressive symptoms. risk factor modification and preventive  Risk factor modification and pharmacotherapy. preventive pharmacotherapy. CAD RADS 3 P1/P2/P3  Consider hospital admission with cardiology P3 or P4  Consider non-atherosclerotic causes of /P4 consultation. symptoms.  Consider CT-FFR, CTP or stress testing  Aggressive risk factor modification  Preventive management, including aggressive and preventive pharmacotherapy. preventive pharmacotherapy. Other treatments CAD RADS 3 P1/P2/P3/P4  Consider CT-FFR, CTP or stress testing (including anti-anginal therapy) should be  Aggressive risk factor modification considered per guideline directed care. and preventive pharmacotherapy. If Iþ  Consider ICA  Other treatments (including anti- CAD RADS P1/P2/P3  Hospital admission with cardiology consultation. anginal therapy) should be considered 4A /P4  Consider ICAa or functional assessmentb per guideline directed care  Preventive management, including aggressive If Iþ  Consider ICA, especially if frequent preventive pharmacotherapy. Other treatments symptoms persist after guideline- (including anti-anginal therapy and options of directed medical therapy revascularization) should be considered per guide- CAD RADS 4 P1/P2/P3/P4  Consider ICAa or functionalb line directed care assessment CAD RADS P1/P2/P3  Hospital admission with cardiology consultation.  Aggressive risk factor modification 4B /P4  ICA is recommended. and preventive pharmacotherapy.  Preventive management, including aggressive  Other treatments (including anti- preventive pharmacotherapy. Other treatments anginal therapy and options of revas- (including anti-anginal therapy and options of cularization) should be considered per revascularization) should be considered per guideline directed care guideline directed care CAD RADS 5 P1/P2/P3/P4  Consider ICAa, functionalb, and/or CAD P1/P2/P3  Hospital admission with cardiology consultation. viability assessment RADS 5 /P4  Expedited ICA and revascularization if suspected  Aggressive risk factor modification acute occlusion. and preventive pharmacotherapy.  Preventive management, including aggressive  Other treatments (including anti- preventive pharmacotherapy. Other treatments anginal therapy and options of revas- (including anti-anginal therapy and options of cularization) should be considered per revascularization) should be considered per guideline directed care guideline directed care. a ICA – invasive coronary angiography may be favored if high-grade stenosis a ICA – invasive coronary angiography may be favored if high-grade stenosis (>90%), high-risk plaque features or I þ (presence of lesion-specific ischemia on (>90%), high-risk plaque features or I þ (presence of lesion-specific ischemia on CT FFR or perfusion defects by CTP) or concordant ischemia by other stress tests CT FFR or perfusion defects by CTP) or concordant ischemia by other stress tests and a candidate for revascularization. It should be clarified that benefit of and a candidate for revascularization. It should be clarified that benefit of revascularization should be confined to patients with persistent symptoms revascularization should be confined to patients with persistent symptoms despite optimal medical therapy. despite optimal medical therapy. b b Functional Assessment includes CT-FFR, CTP, stress testing (ETT, stress Functional Assessment includes CT-FFR, CTP, stress testing (ETT, stress echocardiogram, SPECT, PET, Cardiac MRI) or invasive FFR. echocardiogram, SPECT, PET, Cardiac MRI) or invasive FFR. 553 2022 CAD-RADS Journal of Cardiovascular Computed Tomography 16 (2022) 536–557 Either CT-FFR or CTP can be performed at the time of the CCTA inter- vi. Presence of moderate stenosis (50–69%) with severe amount of pretation or later. If performed later, the recommendation is to update plaque burden and FFR-CT performed with a value < 0.75. CAD- the CAD-RADS score by adding the Modifier “I”. Table 7 summarizes RADS 3/P3/Iþ interpretation of myocardial CTP. vii. Presence of severe stenosis in the distal RCA (70–99%) with moderate amount of plaque burden and stress CTP demonstrating 3.3.6. Modifier E ¼ exceptions no evidence of reversible ischemia. CAD-RADS 4A/P2/I- In clinical practice, sites that have adopted the CAD-RADS classifi- vii. Anomalous left main coronary artery from the right sinus of Val- cation report scores approximately 95% of the time for CCTA.14 In salva with inter-arterial course leading to severe compression and general, CAD-RADS scores are not used in cases of non-atherosclerotic stenosis, absence of coronary plaque and positive stress CTP. CAD- causes of coronary abnormalities, such as coronary dissections, anom- RADS 4A/Iþ/E - Please note that because there is no evidence of alous coronary arteries, coronary artery aneurysms or plaque, the category “P” is not used pseudo-aneurysms, vasculitis, coronary artery fistulas, extrinsic coro- nary artery compression and other causes (Table 3). These exceptions 3.4. Presence of other cardiac or extra-cardiac findings are far less frequent than atherosclerosis as a cause of coronary stenosis or obstruction but remain important differential diagnostic consider- Patients undergoing CCTA may demonstrate other significant, ations and are increasingly being recognized. Therefore, in the updated potentially significant or non-significant cardiac or extra-cardiac find- version of CAD-RADS, a modifier “E” is used to account for any ings. CAD-RADS is intended to focus solely on the classification of cor- non-atherosclerotic narrowing of the coronary arteries and should be onary artery stenosis and further management. However, other cardiac added at the end of the score as a modifier. For example, if an anom- and extra-cardiac findings of relevance should be reported in the body alous coronary artery with inter-arterial course results to a moderate and/or impression of the CCTA report. Specific follow-up and recom- stenosis, then CAD-RADS 3/E should be coded. The modifier “E” will mendations should be included depending on the pathology. have the following purposes: 1- it will allow for non-atherosclerotic Table 8 summarizes the main changes for 2022 CAD-RADS update causes of coronary obstruction to be identifiable in the CAD-RADS when compared to the first version published in 2016. Table 9 describes reporting system; 2- it will provide a framework for tracking of such the potential sources of troponin elevation and Fig. 18 provides a sample etiologies; 3- and it will indicate to the referring clinician that the standardized reporting template for CCTA incorporating CAD-RADS CAD-RADS classification, which is strictly related to atherosclerotic coding. Table 10 summarizes suggested text for recommendations sec- coronary artery disease, may not fully capture the full range of coronary tion of CCTA reporting in patients with stable chest pain and Table 11 abnormalities. summarizes suggested text for recommendations section of CCTA VII. The framework for the new CAD-RADS coding should follow reporting in patients with acute chest pain. three categories: stenosis, plaque and then modifiers. Therefore, the MODIFIERS: The framework for the new CAD-RADS coding should Category “P” for plaque should follow the CAD-RADS score for stenosis. follow: stenosis, plaque and then modifiers. Therefore, The Category “P” Then modifiers should be added, if present. If more than one category for plaque should follow the CAD-RADS score for stenosis. Then the and/or modifier is present, the symbol “/” (slash) should follow each modifier should be added. If more than one modifier or category is modifier in the following order: present, the symbol “/” (slash) should follow each category or modifier in the following order: i. First: modifier N (non-diagnostic) ii. Second: modifier HRP (high-risk plaque) i. First: modifier N (non-diagnostic) iii. Third: modifier I (ischemia) ii. Second: modifier HRP (high-risk plaque) iv. Fourth: modifier S (stent) iii. Third: modifier I (ischemia) v. Fifth: modifier G (graft) iv. Fourth: modifier S (stent) vi. Sixth: modifier E (exceptions) v. Fifth: modifier G (graft) vi. Sixth: modifier E (exceptions) Examples: Modifier E ¼ Exceptions to CAD-RADS/non-atherosclerotic ab- i. Non-interpretable coronary stent with moderate amount of plaque normalities. Modifier E should be used in addition to CAD-RADS 0–5. burden without evidence of other obstructive coronary disease: Non-atherosclerotic narrowing of the coronary arteries may require Categories N and P should be used and Modifier S ¼ CAD- disease-specific management considerations and/or subspecialty RADS N/P2/S. Please note that Category “N” will replace referral. the numerical stenosis grading and will precede Category “P” MODIFIERS: The framework for the new CAD-RADS coding should ii. Presence of a stent and at least one moderate stenosis demon- follow: stenosis, plaque and then modifiers. Therefore, The Category “P” strating severe amount of plaque burden and high-risk plaque for plaque should follow the CAD-RADS score for stenosis. Then the features: Modifiers S and HRP ¼ modifier should be added. If more than one modifier or category is CAD-RADS 3/P3/HRP/S (Fig. 17) present, the symbol “/” (slash) should follow each category or modifier in ii. Presence of stent, grafts, severe amount of plaque burden and non- the following order: evaluable segments due to metal artifacts: Categories N and P and Modifiers S and G ¼ CAD-RADS N/P3/S/G i. First: modifier N (non-diagnostic) iv. Presence of a patent LIMA graft to the LAD and expected occlusion ii. Second: modifier HRP (high-risk plaque) of the proximal LAD and extensive amount of plaque burden in the ii. Third: modifier I (ischemia) native coronary arteries. Mild non-obstructive stenosis in the RCA iv. Fourth: modifier S (stent) and LCX