2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease PDF

Circulation ACC/AHA CLINICAL PRACTICE GUIDELINE 2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease: A Report of the American Heart Association/American College of Cardiology Joint Committee on Clinical Practice Guidelines Developed in collaboration with and endorsed by the Am...

Circulation ACC/AHA CLINICAL PRACTICE GUIDELINE 2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease: A Report of the American Heart Association/American College of Cardiology Joint Committee on Clinical Practice Guidelines Developed in collaboration with and endorsed by the American Association for Thoracic Surgery, American College of ­Radiology, Society of Cardiovascular Anesthesiologists, Society for Cardiovascular Angiography and Interventions, Society of Thoracic Surgeons, and Society for Vascular Surgery Endorsed by the Society of Interventional Radiology and Society for Vascular Medicine Writing Committee Members* Downloaded from http://ahajournals.org by on November 28, 2023 Eric M. Isselbacher, MD, MSc, FACC, Chair; Ourania Preventza, MD, MBA, Vice Chair; James Hamilton Black III, MD, DFSVS, Vice Chair; John G. Augoustides, MD, FAHA†; Adam W. Beck, MD, DFSVS; Michael A. Bolen, MD‡; Alan C. Braverman, MD, FACC; Bruce E. Bray, MD, FACC§; Maya M. Brown-Zimmerman, MPH||; Edward P. Chen, MD, FAHA; Tyrone J. Collins, MD, MSCAI, FACC, FAHA, FSVM¶; Abe DeAnda Jr, MD, FAHA; Christina L. Fanola, MD, MSc; Leonard N. Girardi, MD, FAHA#; Caitlin W. Hicks, MD, MS, FSVS**; Dawn S. Hui, MD; William Schuyler Jones, MD, FACC††; Vidyasagar Kalahasti, MD, FACC; Karen M. Kim, MD, MS‡‡; Dianna M. Milewicz, MD, PhD; Gustavo S. Oderich, MD; Laura Ogbechie, MSN; Susan B. Promes, MD, MBA; Elsie Gyang Ross, MD, MSc; Marc L. Schermerhorn, MD, DFSVS§§; Sabrina Singleton Times, DHSc, MPH||||; Elaine E. Tseng, MD, FAHA; Grace J. Wang, MD, MSCE; Y. Joseph Woo, MD, FACC, FAHA†† AIM: The “2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease” provides recommendations to guide clinicians in the diagnosis, genetic evaluation and family screening, medical therapy, endovascular and surgical treatment, and long-term surveillance of patients with aortic disease across its multiple clinical presentation subsets (ie, asymptomatic, stable symptomatic, and acute aortic syndromes). METHODS: A comprehensive literature search was conducted from January 2021 to April 2021, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, CINHL Complete, and other selected databases relevant to this guideline. Additional relevant studies, published through June 2022 during the guideline writing process, were also considered by the writing committee, where appropriate. STRUCTURE: Recommendations from previously published AHA/ACC guidelines on thoracic aortic disease, peripheral artery disease, and bicuspid aortic valve disease have been updated with new evidence to guide clinicians. In addition, new *Writing committee members are required to recuse themselves from voting on sections to which their specific relationships with industry may apply; see Appendix 1 for detailed information. †SCA representative. ‡ACR representative. §AHA/ACC Joint Committee on Clinical Data Standards liaison. ||Lay stakeholder representative. ¶SCAI representative. #AATS representative. **ACC/AHA Joint Committee on Performance Measures liaison. ††AHA/ACC Joint Committee on Clinical Practice Guidelines liaison. ‡‡STS representative. §§SVS representative. ||||AHA/ACC staff representative. ACC/AHA Joint Committee on Clinical Practice Guidelines Members, see page e445. The American Heart Association requests that this document be cited as follows: Isselbacher EM, Preventza O, Black JH 3rd, Augoustides JG, Beck AW, Bolen MA, Braverman AC, Bray BE, Brown-Zimmerman MM, Chen EP, Collins TJ, DeAnda A Jr, Fanola CL, Girardi LN, Hicks CW, Hui DS, Jones WS, Kalahasti V, Kim KM, Milewicz DM, Oderich GS, Ogbechie L, Promes SB, Ross EG, Schermerhorn ML, Times SS, Tseng EE, Wang GJ, Woo YJ. 2022 ACC/AHA guideline for the diagnosis and management of aortic disease: a report of the American Heart Association/American College of Cardiology Joint Committee on Clinical Practice Guidelines. Circulation. 2022;146:e334–e482. doi: 10.1161/CIR.0000000000001106 © 2022 by the American College of Cardiology Foundation and the American Heart Association, Inc. Circulation is available at www.ahajournals.org/journal/circ e334 December 13, 2022 Circulation. 2022;146:e334–e482. DOI: 10.1161/CIR.0000000000001106 Isselbacher et al 2022 ACC/AHA Aortic Disease Guideline Key Words: AHA Scientific Statements ◼ abdominal aortic aneurysm ◼ aortic dissection ◼ aortitis ◼ aortopathy ◼ bicuspid aortic valve ◼ blunt traumatic aortic injury ◼ cardiac surgery ◼ guidelines ◼ endovascular aortic repair ◼ heritable thoracic aortic disease ◼ intramural hematoma ◼ malperfusion syndrome ◼ Marfan syndrome ◼ Loeys-Dietz syndrome ◼ penetrating atherosclerotic ulcer ◼ thoracic aortic aneurysm ◼ thoracoabdominal aortic aneurysm ◼ thoracic endovascular aortic repair ◼ vascular surgery CONTENTS Downloaded from http://ahajournals.org by on November 28, 2023 Abstract. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . e334 Top 10 Take-Home Messages. . . . . . . . . . . . . . . . . . . . e336 Preamble . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . e337 1. Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . e338 1.1. Methodology and Evidence Review. . . . e338 1.2. Organization of the Writing Committee. . . . . . . . . . . . . . . . . . . . . . . . . . . e338 1.3. Document Review and Approval. . . . . . . e339 1.4. Scope of the Guideline . . . . . . . . . . . . . . . e339 1.5. Class of Recommendations and Level of Evidence . . . . . . . . . . . . . . . . . . . . e339 1.6. Abbreviations. . . . . . . . . . . . . . . . . . . . . . . . e339 2. Normal Anatomy, Abnormal Anatomy, and Definitions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . e340 2.1. Normal Aortic Anatomy. . . . . . . . . . . . . . . e340 2.2. Aortic Landing Zones. . . . . . . . . . . . . . . . . e340 2.3. Definitions of Dilation and Aneurysm of the Aortic Root and Ascending Thoracic Aorta. . . . . . . . . . . . . . . . . . . . . . . . e341 2.3.1. Normalizing Aortic Root and Ascending Aortic Diameters for Body Size . . . . . . . . . . . . . . . . . . . . . e343 2.4. Definitions and Classification of Acute Aortic Syndrome (AAS). . . . . . . . . . e345 2.5. Classification of Thoracoabdominal Aortic Aneurysm (TAAA). . . . . . . . . . . . . . e349 2.6. Classification of Endoleaks. . . . . . . . . . . . e349 3. Imaging and Measurements. . . . . . . . . . . . . . . . . . e349 3.1. Aortic Imaging Techniques to Determine Presence and Progression of Aortic Disease. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . e349 3.2. Conventions of Measurements. . . . . . . . . e352 3.2.1. Computed Tomography. . . . . . . . . e353 3.2.2. Magnetic Resonance Imaging. . . . e353 3.2.3. Echocardiography. . . . . . . . . . . . . . e354 3.2.4. Intravascular Ultrasound. . . . . . . . e354 3.2.5. Abdominal Ultrasound. . . . . . . . . . e355 4. Multidisciplinary Aortic Teams . . . . . . . . . . . . . . . . e355 5. Shared Decision-Making. . . . . . . . . . . . . . . . . . . . . e357 6. Aneurysms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . e358 6.1. Thoracic Aortic Aneurysm (TAA) Causes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . e358 6.1.1. Sporadic and Degenerative TAA. . . . . . . . . . . . . . . . . . . . . . . . . . e361 7. Circulation. 2022;146:e334–e482. DOI: 10.1161/CIR.0000000000001106 6.1.2. Genetic Aortopathies. . . . . . . . . . e361 6.1.3. BAV Aortopathy. . . . . . . . . . . . . . . . e373 6.2. AAA: Cause, Risk Factors, and Screening. . . . . . . . . . . . . . . . . . . . . . . . . . . . . e376 6.3. Growth and Natural History of Aortic Aneurysms . . . . . . . . . . . . . . . . . . . . . e377 6.4. Medical Management of Sporadic and Degenerative Aortic Aneurysm Disease. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . e378 6.4.1. Medical Therapy and Risk Factor Modification in Sporadic TAA. . . . . . . . . . . . . . . . . . e378 6.4.2. Medical Therapy and Risk Factor Modification in AAA. . . . e380 6.4.3. Surveillance for Medical Management . . . . . . . . . . . . . . . . . e382 6.5. Surgical and Endovascular Management of Aortic Aneurysms. . . . . . . . . . . . . . . . . . e384 6.5.1. Surgery for Sporadic Aneurysms of the Aortic Root and Ascending Aorta. . . . . . . . . . . . . . e384 6.5.2. Aortic Arch Aneurysms. . . . . . . . . e387 6.5.3. Descending TAA. . . . . . . . . . . . . . e388 6.5.4. Thoracoabdominal Aortic Aneurysms. . . . . . . . . . . . . . . . . . . e392 6.5.5. Abdominal Aortic Aneurysms. . . . . . . . . . . . . . . . . . . e396 6.5.6. Surveillance After Aneurysm Repair. . . . . . . . . . . . . . . . . . . . . . . . e401 Acute Aortic Syndromes. . . . . . . . . . . . . . . . . . . . . e403 7.1. Presentation. . . . . . . . . . . . . . . . . . . . . . . . . e403 7.2. AAS: Diagnostic Evaluation (Imaging, Laboratory Testing). . . . . . . . . . . . . . . . . . . e404 7.3. Medical Management of AAS. . . . . . . . . e405 7.3.1. Acute Medical Management of AAS. . . . . . . . . . . . . . . . . . . . . . . e405 7.3.2. Subsequent Medical Management of AAS. . . . . . . . . . . . . . . . . . . . . . . e406 7.4. Surgical and Endovascular Management of Acute Aortic Dissection. . . . . . . . . . . . e406 7.4.1. Acute Type A Aortic Dissection. . . . . . . . . . . . . . . . . . . . . e407 7.4.2. Management of Acute Type B Aortic Dissection. . . . . . . . . . . . . . . e411 7.5. Management of IMH . . . . . . . . . . . . . . . . . . e412 December 13, 2022 e335 CLINICAL STATEMENTS AND GUIDELINES recommendations addressing comprehensive care for patients with aortic disease have been developed. There is added emphasis on the role of shared decision making, especially in the management of patients with aortic disease both before and during pregnancy. The is also an increased emphasis on the importance of institutional interventional volume and multidisciplinary aortic team expertise in the care of patients with aortic disease. Isselbacher et al CLINICAL STATEMENTS AND GUIDELINES 7.6. 8. Downloaded from http://ahajournals.org by on November 28, 2023 9. 2022 ACC/AHA Aortic Disease Guideline Management of PAU. . . . . . . . . . . . . . . . . . e414 7.6.1. PAU With IMH, Rupture, or Both . . . . . . . . . . . . . . . . . . . . . . . . . . e414 7.6.2. Isolated PAU. . . . . . . . . . . . . . . . . . . e415 7.6.3. PAU Open Surgical Repair Versus Endovascular Repair . . . . . . . . . . . e416 7.7. Traumatic Aortic Injury. . . . . . . . . . . . . . . . . e416 7.7.1. Initial Management of Blunt Traumatic Thoracic Aortic Injury (BTTAI). . . . . . . . . . . . . . . . . . . . . . . . e416 7.7.2. Initial Management of Blunt Traumatic Abdominal Aortic Injury (BAAI). . . . . . . . . . . . . . . . . . . e419 7.7.3. Long-Term Management and Surveillance After Blunt Traumatic Aortic Injury (BTAI). . . . . . . . . . . . . e421 7.8. Long-Term Management and Surveillance Imaging After AAS . . . . . . . . . . . . . . . . . . . . e421 7.8.1. Long-Term Surveillance Imaging After Aortic Dissection and IMH. . . . . . . . . . . . . . . . . . . . . . . . . . . e421 7.8.2. Long-Term Management After Acute Aortic Dissection and IMH. . . . . . . . . . . . . . . . . . . . . . . . . . . e422 7.8.3. Long-Term Management and Surveillance for PAUs. . . . . . . . . . e422 Pregnancy in Patients With Aortopathy. . . . . . . . e423 8.1. Counseling and Management of Aortic Disease in Pregnancy and Postpartum. . . . . . . . . . . . . . . . . . . . . . . . . . . e423 8.2. Delivery in Pregnant Patients With Aortopathy. . . . . . . . . . . . . . . . . . . . . . . . . . . . e424 8.3. Surgery Before Pregnancy in Women With Aortic Disease. . . . . . . . . . . . . . . . . . . e425 8.4. Pregnancy in Patients With Aortopathy: Aortic Dissection and Aortic Surgery in Pregnancy. . . . . . . . . . . . . . . . . . . . . . . . . . . . e427 Other Aortic Conditions. . . . . . . . . . . . . . . . . . . . . . e428 9.1. Inflammatory Aortitis: Diagnosis and Treatment of Takayasu Arteritis and Giant Cell Arteritis (GCA). . . . . . . . . . . . . . e428 9.2. Infectious Aortitis. . . . . . . . . . . . . . . . . . . . . . e432 9.2.1. Diagnosis and Management of Infection of the Native Aorta . . . . . . . . . . . . . . . . . . . . . . . . . e432 9.2.2. Diagnosis and Management of Prosthetic Aortic Graft Infection. . . . . . . . . . . . . . . . . . . . . . . e434 9.3. Atherosclerotic Disease. . . . . . . . . . . . . . . . e435 9.3.1. Aortic Thrombus. . . . . . . . . . . . . . e436 9.3.2. Aortic Occlusion. . . . . . . . . . . . . . e436 9.3.3. Porcelain Aorta. . . . . . . . . . . . . . . e436 9.4. Coarctation of the Aorta (CoA) and Congenital Abnormalities of the Arch. . . e437 9.4.1. Coarctation of the Aorta. . . . . . . . e437 9.4.2. Other Arch Abnormalities. . . . . . e438 e336 December 13, 2022 9.5. Tumors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . e441 10. Physical Activity and Quality of Life. . . . . . . . . . . e441 11. Cost and Value Considerations. . . . . . . . . . . . . . . e442 12. Evidence Gaps and Future Directions. . . . . . . . . e443 12.1. Biomarker Studies. . . . . . . . . . . . . . . . . . . . . e443 12.2. Genetic and Nongenetic Factors. . . . . . . e443 12.3. Biomechanics of the Aorta. . . . . . . . . . . . . e443 12.4. Sex, Race, and Ethnicity. . . . . . . . . . . . . . . e443 12.5. Quality of Life in Patients With Aortic Disease. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . e444 12.6. New Endovascular Technology. . . . . . . . . e444 12.7. Optimal Exercise and Rehabilitation Protocols. . . . . . . . . . . . . . . . . . . . . . . . . . . . . e444 12.8. Equitable Care and Training Opportunities . . . . . . . . . . . . . . . . . . . . . . . . . e444 References�������������������������������������������������������������������������� e445 Appendix 1 Author Relationships With Industry and Other Entities (Relevant). . . . . . . . . . . . . . . . . . . . . . . . . . . e478 Appendix 2 Reviewer Relationships With Industry and Other Entities (Comprehensive). . . . . . . . . . . . . . . . . . . e481 TOP 10 TAKE-HOME MESSAGES FOR THE DIAGNOSIS AND MANAGEMENT OF AORTIC DISEASE 1. Because outcomes for patients with aortic disease are enhanced at programs with higher volumes, experienced practitioners, and extensive management capabilities, Multidisciplinary Aortic Team care is considered in determining the appropriate timing of intervention. 2. Shared decision-making involving the patient and a multidisciplinary team is highly encouraged to determine the optimal medical, endovascular, and open surgical therapies. In patients with aortic disease who are contemplating pregnancy or who are pregnant, shared decision-making is especially important when considering the cardiovascular risks of pregnancy, the diameter thresholds for prophylactic aortic surgery, and the mode of delivery. 3. Computed tomography, magnetic resonance imaging, and echocardiographic imaging of patients with aortic disease should follow recommended approaches for image acquisition, measurement and reporting of relevant aortic dimensions, and the frequency of surveillance before and after intervention. 4. At centers with Multidisciplinary Aortic Teams and experienced surgeons, the threshold for surgical intervention for sporadic aortic root and ascending aortic aneurysms has been lowered from 5.5 cm to 5.0 cm in selected patients, and even lower in specific scenarios among patients with heritable thoracic aortic aneurysms. Circulation. 2022;146:e334–e482. DOI: 10.1161/CIR.0000000000001106 Isselbacher et al PREAMBLE Since 1980, the American College of Cardiology (ACC) and American Heart Association (AHA) have translated scientific evidence into clinical practice guidelines with recommendations to improve cardiovascular health. These guidelines, which are based on systematic methods to evaluate and classify evidence, provide a foundation for the delivery of quality cardiovascular care. The ACC and AHA sponsor the development and publication of clinical practice guidelines without commercial support, and members volunteer their time to the writing and review efforts. Guidelines are official policy of the ACC and AHA. For some guidelines, the ACC and AHA collaborate with other organizations. Intended Use Clinical practice guidelines provide recommendations applicable to patients with or at risk of developing cardiovascular disease. The focus is on medical practice in the United States, but these guidelines are relevant to patients throughout the world. Although guidelines may be used to inform regulatory or payer decisions, the intent is to improve quality of care and align with patients’ interests. Guidelines are intended to define practices meeting the needs of patients in most, but not all, circumstances and should not replace clinical judgment. Clinical Implementation Management, in accordance with guideline recommendations, is effective only when followed by both practitioners and patients. Adherence to recommendations can be enhanced by shared decision-making between clinicians and patients, with patient engagement in selecting interventions on the basis of individual values, preferences, and associated conditions and comorbidities. Methodology and Modernization The AHA/ACC Joint Committee on Clinical Practice Guidelines (Joint Committee) continuously reviews, updates, and modifies guideline methodology on the basis of published standards from organizations, including the Institute of Medicine,1,2 and on the basis of internal reevaluation. Similarly, presentation and delivery of guidelines are reevaluated and modified in response to evolving technologies and other factors to optimally facilitate dissemination of information to health care professionals at the point of care. Numerous modifications to the guidelines have been implemented to make them shorter and enhance “user friendliness.” Guidelines are written and presented in a modular, “knowledge chunk” format, in which each chunk includes a table of recommendations, a brief synopsis, recommendation-specific supportive text and, when appropriate, flow diagrams or additional tables. Hyperlinked references are provided for each modular knowledge chunk to facilitate quick access and review. In recognition of the importance of cost–value considerations, in certain guidelines, when appropriate and feasible, an analysis of value for a drug, device, or intervention may be performed in accordance with the ACC/ AHA methodology.3 To ensure that guideline recommendations remain current, new data will be reviewed on an ongoing basis by the writing committee and staff. Going forward, targeted sections/knowledge chunks will be revised dynamically after publication and timely peer review of potentially practice-changing science. The previous designations of “full revision” and “focused update” will be phased out. For additional information and policies on guideline development, readers may consult the ACC/AHA guideline methodology manual4 and other methodology articles.5-7 Selection of Writing Committee Members The Joint Committee strives to ensure that the guideline writing committee contains requisite content expertise Circulation. 2022;146:e334–e482. DOI: 10.1161/CIR.0000000000001106 December 13, 2022 e337 CLINICAL STATEMENTS AND GUIDELINES Downloaded from http://ahajournals.org by on November 28, 2023 5. In patients who are significantly smaller or taller than average, surgical thresholds may incorporate indexing of the aortic root or ascending aortic diameter to either patient body surface area or height, or aortic cross-sectional area to patient height. 6. Rapid aortic root growth or ascending aortic aneurysm growth, an indication for intervention, is defined as ≥0.5 cm in 1 year or ≥0.3 cm per year in 2 consecutive years for those with sporadic aneurysms and ≥0.3 cm in 1 year for those with heritable thoracic aortic disease or bicuspid aortic valve. 7. In patients undergoing aortic root replacement surgery, valve-sparing aortic root replacement is reasonable if the valve is suitable for repair and when performed by experienced surgeons in a Multidisciplinary Aortic Team. 8. Patients with acute type A aortic dissection, if clinically stable, should be considered for transfer to a high-volume aortic center to improve survival. The operative repair of type A aortic dissection should entail at least an open distal anastomosis rather than just a simple supracoronary interposition graft. 9. There is an increasing role for thoracic endovascular aortic repair in the management of uncomplicated type B aortic dissection. Clinical trials of repair of thoracoabdominal aortic aneurysms with endografts are reporting results that suggest endovascular repair is an option for patients with suitable anatomy. 10. In patients with aneurysms of the aortic root or ascending aorta, or those with aortic dissection, screening of first-degree relatives with aortic imaging is recommended. 2022 ACC/AHA Aortic Disease Guideline CLINICAL STATEMENTS AND GUIDELINES Isselbacher et al 2022 ACC/AHA Aortic Disease Guideline and is representative of the broader cardiovascular community by selection of experts across a spectrum of backgrounds, representing different geographic regions, sexes, races, ethnicities, intellectual perspectives/biases, and clinical practice settings. Organizations and professional societies with related interests and expertise are invited to participate as partners or collaborators. Recommendations are limited to drugs, devices, and treatments approved for clinical use in the United States. Joshua A. Beckman, MD, MS, FACC, FAHA Chair, AHA/ACC Joint Committee on Clinical Practice Guidelines 1. INTRODUCTION Relationships With Industry and Other Entities 1.1. Methodology and Evidence Review The ACC and AHA have rigorous policies and methods to ensure that documents are developed without bias or improper influence. The complete policy on relationships with industry and other entities (RWI) can be found online. Appendix 1 of the guideline lists writing committee members’ relevant RWI. For the purposes of full transparency, their comprehensive disclosure information is available in a Supplemental Appendix. Comprehensive disclosure information for the Joint Committee is also available online. The recommendations listed in this guideline are, whenever possible, evidence based. An initial extensive evidence review, which included literature derived from research involving human subjects, published in English, and indexed in MEDLINE (through PubMed), EMBASE, the Cochrane Library, the Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline, was conducted from February 2021 to April 2021. Search terms included both key words and index terms (eg, MeSH, Emtree); search terms included but were not limited to the following: aortic occlusion; aortic aneurysm; aortic aneurysm, thoracic; aortic aneurysm, abdominal; surveillance after endovascular aneurysm repair; diagnostic imaging; monitoring; surveillance; imaging; aorta; aortic; computed tomography; ultrasound; magnetic resonance imaging; arterial occlusive diseases; aortic diseases; aortic atherosclerosis; atherosclerosis; clinical trial; observational study; randomized controlled trial; review; atherosclerotic aortic disease; plaque, atherosclerotic; aorta; aortitis; infectious; autoimmune; aortic rupture; penetrating aortic ulcers; comparative studies; nonexperimental studies; type A aortic dissection; type A; type B; aneurysm, dissecting; aorta and echocardiography. The final evidence tables are included in the Online Data Supplement and summarize the evidence used by the writing committee to formulate recommendations. References selected and published in the present document are representative and not all-inclusive. Evidence Review and Evidence Review Committees Downloaded from http://ahajournals.org by on November 28, 2023 In developing recommendations, the writing committee uses evidence-based methodologies that are based on all available data.4,5 Literature searches focus on randomized controlled trials (RCTs) but also include registries, nonrandomized comparative and descriptive studies, case series, cohort studies, systematic reviews, and expert opinion. Only key references are cited. An independent evidence review committee is commissioned when there are ≥1 question(s) deemed of utmost clinical importance and merit formal systematic review to determine which patients are most likely to benefit from a drug, device, or treatment strategy, and to what degree. Criteria for commissioning an evidence review committee and formal systematic review include absence of a current authoritative systematic review, feasibility of defining the benefit and risk in a time frame consistent with the writing of a guideline, relevance to a substantial number of patients, and likelihood that the findings can be translated into actionable recommendations. Evidence review committee members may include methodologists, epidemiologists, clinicians, and biostatisticians. Recommendations developed by the writing committee on the basis of the systematic review are marked “SR”. Guideline-Directed Medical Therapy The term guideline-directed medical therapy encompasses clinical evaluation, diagnostic testing, and both pharmacological and procedural treatments. For these and all recommended drug treatment regimens, the reader should confirm dosage with product insert material and evaluate for contraindications and interactions. e338 December 13, 2022 1.2. Organization of the Writing Committee The writing committee consisted of clinicians, cardiologists, internists, interventionalists, surgeons, radiologists, anesthesiologists, a nurse practitioner, and a lay/patient representative. The writing committee included representatives from the ACC, AHA, American Association for Thoracic Surgery, American College of Radiology, Society of Cardiovascular Anesthesiologists, Society for Cardiovascular Angiography and Interventions, Society of Thoracic Surgeons (STS), and Society for Vascular Surgery (SVS). Appendix 1 of the present document lists writing committee members’ relevant RWI. For the purposes of full transparency, the writing committee members’ comprehensive disclosure information is available in a Supplemental Appendix. Circulation. 2022;146:e334–e482. DOI: 10.1161/CIR.0000000000001106 Isselbacher et al 2022 ACC/AHA Aortic Disease Guideline Abbreviation Meaning/Phrase The Joint Committee appointed a peer review committee to review the document. The peer review committee was comprised of individuals nominated by ACC, AHA, and the collaborating organizations. Reviewers’ RWI information was distributed to the writing committee and is published in this document (Appendix 2). This document was approved for publication by the governing bodies of the ACC and the AHA and was endorsed by the American Association for Thoracic Surgery, American College of Radiology, Society of Cardiovascular Anesthesiologists, Society for Cardiovascular Angiography and Interventions, Society of Interventional Radiology, Society of Thoracic Surgeons, Society for Vascular Medicine, and Society for Vascular Surgery. BP blood pressure BSA body surface area BTAI blunt traumatic aortic injury BTTAI blunt traumatic thoracic aortic injury CMR cardiac magnetic resonance CoA coarctation of the aorta CT computed tomography CTA computed tomographic angiography DBP diastolic blood pressure DMARD disease-modifying anti-rheumatic drug ECG electrocardiogram EVAR endovascular abdominal aortic aneurysm repair FID focal intimal disruption 1.4. Scope of the Guideline FDA US Food and Drug Administration FDG-PET fluorodeoxyglucose–positron emission tomography FEVAR fenestrated endovascular aortic repair GCA giant cell arteritis HRQOL health-related quality of life HTAD heritable thoracic aortic disease ICU intensive care unit IMH intramural hematoma IRAD International Registry of Acute Aortic Dissection 1.5. Class of Recommendations and Level of Evidence LDL low-density lipoprotein LVV large vessel vasculitis The Class of Recommendation (COR) indicates the strength of recommendation, encompassing the estimated magnitude and certainty of benefit in proportion to risk. The Level of Evidence (LOE) rates the quality of scientific evidence supporting the intervention on the basis of the type, quantity, and consistency of data from clinical trials and other sources (Table 2).1 MR magnetic resonance MRA magnetic resonance angiography MRI magnetic resonance imaging nsHTAD nonsyndromic heritable thoracic aortic disease PAD peripheral artery disease PAU penetrating atherosclerotic ulcer PET positron emission tomography rAAA ruptured abdominal aortic aneurysm RCT randomized controlled trial In developing the “2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease” (2022 aortic disease guideline), the writing committee reviewed previously published guidelines. Table 1 contains a list of these publications deemed pertinent to this writing effort and is intended for use as a resource, thus obviating the need to repeat existing guideline recommendations. Downloaded from http://ahajournals.org by on November 28, 2023 1.6. Abbreviations Abbreviation Meaning/Phrase REBOA resuscitative endovascular balloon occlusion of the aorta 3D 3-dimensional rEVAR endovascular repair for rAAA AAA abdominal aortic aneurysm SMA superior mesenteric artery AAS acute aortic syndrome SBP systolic blood pressure ACEI angiotensin-converting enzyme inhibitor SCI spinal cord injury AHI aortic height index TAA thoracic aortic aneurysm AR aortic regurgitation TAAA thoracoabdominal aortic aneurysm ARB angiotensin receptor blocker TAAD thoracic aortic aneurysm and dissection ASCA aberrant subclavian artery TAD thoracic aortic disease ASCVD atherosclerotic cardiovascular disease TAR total arch replacement ASI aortic size index TEE transesophageal echocardiography AVR aortic valve replacement TEVAR thoracic endovascular aortic repair BAAI blunt traumatic abdominal aortic injury TTE transthoracic echocardiography BAV bicuspid aortic valve VSRR valve-sparing root replacement Circulation. 2022;146:e334–e482. DOI: 10.1161/CIR.0000000000001106 December 13, 2022 e339 CLINICAL STATEMENTS AND GUIDELINES 1.3. Document Review and Approval Isselbacher et al 2022 ACC/AHA Aortic Disease Guideline CLINICAL STATEMENTS AND GUIDELINES Table 1. Associated Guidelines Organization Publication Year (Reference) Thoracic endovascular aortic repair for descending thoracic aortic aneurysms SVS 20211 Valvular heart disease ACC/AHA 20202 Large vessel vasculitis EULAR 20203 Blood cholesterol AHA/ACC/AACVPR/AAPA/ABC/ACPM/ADA/AGS/ APhA/ASPC/NLA/PCNA 20194 Congenital heart disease AHA/ACC 20195 Abdominal aortic aneurysm SVS 20186 High blood pressure ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ ASPC/NMA/PCNA 20187 Lower extremity peripheral artery disease AHA/ACC 20178 Descending thoracic aorta diseases ESVS 20179 Bicuspid aortic valves statement of clarification ACC/AHA 201610 Vascular graft infections, mycotic aneurysms, and endovascular infections AHA 201611 Endovascular repair of traumatic thoracic aortic injury SVS 201112 Thoracic aortic disease ACCF/AHA/AATS/ACR/ASA/SCA/SCAI/SIR/STS/ SVM 201013 Coronary and other atherosclerotic vascular disease AHA/ACC 200614 Acute type A aortic dissection AATS 202115 Type B aortic dissection STS 202216 Title Guidelines Downloaded from http://ahajournals.org by on November 28, 2023 AACVPR indicates American Association of Cardiovascular and Pulmonary Rehabilitation; AAPA, American Academy of Physician Assistants; AATS, American Association for Thoracic Surgery; ABC, Association of Black Cardiologists; ACC, American College of Cardiology; ACCF, American College of Cardiology Foundation; ACPM, American College of Preventive Medicine; ACR, American College of Radiology; ADA, American Diabetes Association; AGS, American Geriatrics Society; AHA, American Heart Association; APhA, American Pharmacists Association; ASA, American Society of Anesthesiologists; ASH, American Society of Hematology; ASPC, American Society for Preventive Cardiology; ESVS, European Society for Vascular Surgery; EULAR, European League Against Rheumatism; NLA, National Lipid Association; NMA, National Medical Association; PCNA, Preventive Cardiovascular Nurses Association; SCA, Society of Cardiovascular Anesthesiologists; SCAI, Society for Cardiovascular Angiography and Interventions; SIR, Society of Interventional Radiology; STS, Society of Thoracic Surgeons; SVM, Society for Vascular Medicine; and SVS, Society for Vascular Surgery. 2. NORMAL ANATOMY, ABNORMAL ANATOMY, AND DEFINITIONS 2.1. Normal Aortic Anatomy The aorta is the largest artery in the body and can be divided into 5 main anatomic segments (Figure 1): the root or sinus segment, which extends from the aortic valve annulus to the sinotubular junction; the ascending thoracic aorta, which extends from the sinotubular junction to the innominate artery; the aortic arch, which extends from the innominate to the left subclavian artery; the descending thoracic aorta, which extends from the left subclavian artery to the diaphragm; and the abdominal aorta, which extends from the diaphragm to the level of the aortic bifurcation. The aortic wall is composed of 3 layers (Figure 2): a thin inner intima, a thicker central media, and a thin outer adventitia. The intima consists of a layer of endothelial cells within a matrix of connective tissue. The media consists of smooth muscle cells, elastic fibers, collagen proteins, and polysaccharides sandwiched in >50 layers known as elastic lamellae. The media provides strength e340 December 13, 2022 and distensibility to the aorta, features that are critical to circulatory function. The adventitia is composed of connective tissue, fibroblasts, nerves, and the vasa vasorum, which perfuse the outer aortic wall and a substantial portion of the media. 2.2. Aortic Landing Zones In addition to the standard anatomic descriptors of the aortic anatomy, there is a more technical classification of aortic anatomy that is used to plan, guide, and report aortic interventions, especially endovascular stent-grafting. Because the clinical success of thoracic aortic endovascular procedures is influenced by the proximal sealing zone, in this system the thoracic and abdominal aorta are divided into 11 landing zones, as detailed in Figure 3. Note that Roselli et al2 have proposed a modification of zone 0, dividing it into 3 subsegments, in which 0A extends from the annulus to the distal margin of the highest coronary, 0B extends above the coronary to the distal margin of the right pulmonary artery, and 0C extends from the right pulmonary artery to the distal end of the origin of the innominate artery. Circulation. 2022;146:e334–e482. DOI: 10.1161/CIR.0000000000001106 Isselbacher et al 2022 ACC/AHA Aortic Disease Guideline Downloaded from http://ahajournals.org by on November 28, 2023 2.3. Definitions of Dilation and Aneurysm of the Aortic Root and Ascending Thoracic Aorta The conventional definition of an arterial aneurysm is any artery that is dilated to at least 1.5 times its expected normal diameter.3 This definition applies well to the abdominal and descending thoracic aorta. However, it has long been recognized that this definition fails when it comes to defining aneurysms of the aortic root and ascending thoracic aorta. For example, a man in his 40s would be expected to have an average aortic root diameter of 3.5 cm; applying the standard definition of ≥1.5 times reference diameter, his aortic root would have to reach 5.25 cm before it would be considered an aneurysm, whereas most experts would consider his aorta to be an aneurysm well below that diameter. Indeed, if this patient had Marfan syndrome or a familial thoracic aortic aneurysm, aortic repair would be recommended at a diameter of ≤5.0 cm, a size that would not even be large enough to be termed an “aneurysm.” The most important consideration in deciding the diameter thresholds at which to call the root and ascending aorta dilated or aneurysmal is based on the natural history of such abnormal aortas. Borger et al4 studied 201 patients with bicuspid aortic valve (BAV) undergoing aortic valve replacement (AVR) (those undergoing concomitant replacement of the ascending aorta were excluded) and followed them for 10 to 15 years; they found that those with baseline aortic diameters of 4.5 cm to 4.9 cm had a significantly increased risk of aneurysm, Circulation. 2022;146:e334–e482. DOI: 10.1161/CIR.0000000000001106 December 13, 2022 e341 CLINICAL STATEMENTS AND GUIDELINES Table 2. Applying American College of Cardiology/American Heart Association Class of Recommendation and Level of Evidence to Clinical Strategies, Interventions, Treatments, or Diagnostic Testing in Patient Care* (Updated May 2019) 2022 ACC/AHA Aortic Disease Guideline CLINICAL STATEMENTS AND GUIDELINES Isselbacher et al Downloaded from http://ahajournals.org by on November 28, 2023 Figure 1. The Anatomy of the Aorta and Its Main Branches. dissection, or sudden death (P<0.001) compared with those with diameters <4.5 cm (Figure 4). To evaluate the risk of type A aortic dissection at various diameters below the traditional 5.5 cm threshold for prophylactic aortic repair, Paruchuri et al5 plotted a distribution curve of ascending aortic size in a community sample from the MESA (Multi-Ethnic Study of Atherosclerosis) e342 December 13, 2022 database. They then analyzed the number of dissections (numerator) at each aortic diameter and the population at risk at each aortic diameter (denominator). They found that, relative to a control aortic diameter of ≤3.4 cm, a diameter of 4.0 cm to 4.4 cm conferred an 89-fold increased risk of dissection, and a diameter of ≥4.5 cm conferred a 6000fold increased risk (Figure 5), albeit these are only relative Circulation. 2022;146:e334–e482. DOI: 10.1161/CIR.0000000000001106 Isselbacher et al 2022 ACC/AHA Aortic Disease Guideline CLINICAL STATEMENTS AND GUIDELINES Figure 2. A Simplified Diagram Depicting the Key Histologic Components of the Aortic Wall. The medial layer in human aortas contains >50 alternating layers of elastin and smooth muscle cells (whereas only 5 are shown in this simplified illustration). Adapted (cropped) from “Illustration of tunics of the arteries vs veins” by Malgosia Wilk-Blaszczak, used under CC-BY 4.0. “Illustration of tunics of the arteries vs veins” is adapted (cropped) from figure 20.3 in BC OpenStax Anatomy and Physiology used under CC-BY 4.0. Downloaded from http://ahajournals.org by on November 28, 2023 risk estimates and do not inform absolute risk. It follows that the increase in risk at 4.0 cm to 4.4 cm justifies defining an aorta of this size “dilated,” and the abrupt increase in risk at a diameter of ≥4.5 cm justifies defining an aorta of this size as an “aneurysm.” Using this approach, of the subjects in the MESA database, only 2.6% would be considered to have a dilated aorta and only 0.2% to have an aneurysm. This definition of a dilated ascending aorta being ≥4.0 cm is consistent with what was proposed in the 2014 European Society of Cardiology guidelines on the diagnosis and treatment of aortic diseases, in which aortic “dilation” was similarly defined as an aorta diameter of >4.0 cm.6 Finally, in the clinical setting, the term “dilation” is preferred to “ectasia” to describe mild aortic enlargement. Historically, there has been a lack of uniformity in the use of “ectasia” in image interpretation. Many radiologists use “ectatic” rather than “dilated” to describe a mildly enlarged aorta, whereas others use “ectatic” to describe an abnormal aortic shape, such as a “tortuous” aorta.7 Even more problematic is the fact that some imaging groups use the term “ectasia” to describe larger aortas, such as those 4.5 cm to 5.4 cm in diameter,8 which overlaps with what most experts would consider to be an aneurysm. Lastly, in imaging of the coronary arteries, “ectasia” is typically used to describe diffuse (rather than focal) coronary artery dilation,9 which may lead to some clinical uncertainty when “ectasia” is applied to the aorta. Figure 3. Classification of Aortic Anatomic Segments by 11 Landing Zones. Zone 0 (involves the ascending to distal end of the origin of the innominate artery); Zone 1 (involves the origin of the left common carotid; between the innominate and the left carotid); Zone 2 (involves the origin of the left subclavian; between the left carotid and the left subclavian); Zone 3 (involves the proximal descending thoracic aorta down to the T4 vertebral body; the first 2 cm distal to the left subclavian); Zone 4 (the end of zone 3 to the mid-descending aorta – T6); Zone 5 (the mid-descending aorta to the celiac); Zone 6 (involves the origin of the celiac; the celiac to the superior mesenteric); Zone 7 (involves the origin of the superior mesenteric artery; the superior mesenteric to the renals); Zone 8 (involves the origin of the renal arteries; the renal to the infrarenal abdominal aorta); Zone 9 (the infrarenal abdominal aorta to the level of aortic bifurcation ); Zone 10 (the common iliac); Zone 11 (involves the origin of the external iliac arteries). From Czerny et al.1 Copyright 2019, with permission from Elsevier, Inc., Now Medical Studios, and Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. 2.3.1. Normalizing Aortic Root and Ascending Aortic Diameters for Body Size As with the aortic diameter thresholds for surgery presented in this guideline, it recognized that the 4.0 cm and 4.5 cm diameter thresholds discussed previously Circulation. 2022;146:e334–e482. DOI: 10.1161/CIR.0000000000001106 December 13, 2022 e343 2022 ACC/AHA Aortic Disease Guideline CLINICAL STATEMENTS AND GUIDELINES Isselbacher et al Figure 4. Freedom From Ascending Aortic Complications for Patients With Bicuspid Aortic Valve Disease. Patients with moderate dilation of the ascending aorta (4.5 cm–4.9 cm) had a significantly increased risk of future aortic complications (aneurysm, dissection, or sudden death). Reprinted from Borger et al.4 Copyright 2004, with permission from Elsevier, Inc. and the American Association for Thoracic Surgery. Downloaded from http://ahajournals.org by on November 28, 2023 are intended for those whose height, body surface area (BSA), or both is within 1 to 2 standard deviations of the mean. For male and female patients who are significantly shorter or taller than average, these diameters need to be adjusted downward or upward, accordingly. Several methods to normalize aortic diameter are currently used in clinical practice and clinical research. The Z-Score The z-score is routinely used to assess aortic dilation in the pediatric population, as changes in a child’s age and body size make it especially challenging to define normal aortic size and to distinguish normal from pathologic aortic growth. Nomograms have been established correlating BSA and aortic root diameter to generate the z-score. One limitation of the reliance on BSA is that there are multiple formulae to calculate BSA that yield different results for the same patient. A second limitation is that multiple z-score calculators exist, each performing differently.10 Finally, most of the literature on the natural history of acute aortic syndromes (AAS) is based on aortic diameters, whereas reports of outcome based on z-scores are limited, so the z-score is not typically used to report the degree of aortic dilation in adults. The Aortic Size Index and Aortic Height Index Most often, in the clinical care of adult patients, aortic diameters are normalized using a ratio of aortic diameter Figure 5. Relative Risk of Aortic Dissection by Size Range. The relative risk of aortic dissection begins to increase appreciably at a diameter of 4.0 cm to 4.4 cm and then increases dramatically at a diameter of ≥4.5 cm. Reprinted from Paruchuri et al.5 Copyright 2005, with permission from Karger Publishers, Basel‚ Switzerland. e344 December 13, 2022 Circulation. 2022;146:e334–e482. DOI: 10.1161/CIR.0000000000001106 Isselbacher et al pler cross-sectional area to height ratio of ≥10 cm2/m (rather than >10 cm2/m) as the threshold predictive of increased risk.14,15 2.4. Definitions and Classification of Acute Aortic Syndrome (AAS) AAS are life-threatening conditions in which there is a breach in the integrity of the aortic wall. The most common AAS are aortic dissection, intramural hematoma (IMH), and penetrating atherosclerotic ulcer (PAU), all of which can lead to rupture (Figure 6). 2.4.1. Aortic Dissection Aortic dissection is the most common of the AAS. Aortic dissection occurs when there is an intimal tear that allows the blood to pass through the tear and into the aortic media, splitting the intima in 2 longitudinally, creating a dissection flap that divides the true lumen from a newly formed false lumen (Figure 6). The dissection flap can propagate in an antegrade or retrograde fashion and lead to a number of life-threatening complications, including acute aortic regurgitation (AR), myocardial ischemia, cardiac tamponade, acute stroke, or malperfusion syndromes. The blood surging in the false lumen Downloaded from http://ahajournals.org by on November 28, 2023 Figure 6. Acute Aortic Syndromes. In aortic dissection, a tear in the aortic intima allows blood to penetrate the aortic media, pushing the dissection flap into the middle of the aorta, separating the true from the false lumen. In intramural hematoma, blood leaks into the aortic media at low pressure, forming a thrombus that pushes the outer wall of the aorta outward, leaving a relatively normal appearing aortic lumen. A penetrating atherosclerotic ulcer allows blood to enter the aortic media, but atherosclerotic scarring of the aorta typically confines the blood collection, often resulting in a localized dissection or pseudoaneurysm. Adapted with permission from Springer Nature Customer Service Centre GmbH: Springer Nature, Clough et al‚1 Copyright 2015. Circulation. 2022;146:e334–e482. DOI: 10.1161/CIR.0000000000001106 December 13, 2022 e345 CLINICAL STATEMENTS AND GUIDELINES to BSA or aortic diameter to the patient’s height. In 2006, Davies et al11 showed that aortic size index (ASI), which is defined as aortic diameter (cm)/BSA(m2), is a better predictor of adverse aortic events than diameter alone, and that a simple nomogram could be used to stratify those with aortic aneurysms into low-, medium-, and high-risk groups. However, it is unclear whether the weight of an adult has a significant impact on the expected normal aortic diameter, and one would not expect a patient’s aorta to grow or shrink with significant fluctuations in weight. Zafar et al12 therefore examined whether aortic height index (AHI), which is defined as aortic diameter (cm)/patient height (m), might perform better than the ASI, and they reported that the AHI performed at least as well as the ASI12 and had the advantage of being simpler to calculate. The Cross-Sectional Area to Height Ratio Another approach to normalizing aortic size to height was proposed by Svensson et al in 200213 in which they calculated a ratio of the cross-sectional area of the aorta (cm) to the patient’s height (m). The initial studies used a cross-sectional area to height ratio of >10 cm2/m as a threshold for intervention because of a significant increase in risk of adverse events; notably, in more contemporary reports, this group has shown the sim- 2022 ACC/AHA Aortic Disease Guideline CLINICAL STATEMENTS AND GUIDELINES Isselbacher et al 2022 ACC/AHA Aortic Disease Guideline Table 3. Classification of Aortic Dissection Chronicity Based on the 2020 SVS/STS Reporting Standards Chronicity Time From Onset of Symptoms Hyperacute <24 h Acute 1–14 d Subacute 15–90 d Chronic >90 d Adapted with permission from Springer Nature Customer Service Centre GmbH: Springer Nature, Clough RE, et al.1 Copyright 2015. STS indicates Society of Thoracic Surgeons; and SVS, Society for Vascular Surgery. may rupture back through the intima into the true lumen, creating a reentry tear. If the blood in the false lumen instead tears through the outer media and adventitia, aortic rupture will result. The incidence of aortic dissection is estimated to be 5 to 30 cases per million people per year, with men more commonly affected. Most dissections occur in those between the ages of 50 to 70 years, although patients with Marfan syndrome, BAV, Loeys-Dietz syndrome, and vascular Ehlers-Danlos syndrome, present at younger ages. 2.4.1.1. Definition Aortic dissection has traditionally been defined as “acute” during the first 2 weeks after symptom onset and “chronic” when beyond the second week. Investigators from the International Registry of Acute Aortic Dissection (IRAD) proposed that aortic dissection be divided into 4 temporal types: hyperacute (<24 h), acute (2–7 d), subacute (8–30 d), and chronic (>30 d).2 The most contemporary temporal classification system, proposed by the SVS and STS, similarly divides aortic dissection into 4 temporal types, as shown in Table 3, to improve prognostication and guide decision making about the timing and types of potential intervention. Acute aortic dissection of the ascending aorta is highly lethal in symptomatic patients left untreated, with an early mortality of 1% to 2% per hour after symptom onset.3 The mortality rate is increased among patients who present with or develop complications of cardiac tamponade (with or without cardiogenic shock), acute myocardial ischemia or infarction, stroke, or organ malperfusion.3 Patients with uncomplicated acute type B aortic dissection have a 30-day mortality rate of 10%. However, when patients with acute type B aortic dissection develop complica- Downloaded from http://ahajournals.org by on November 28, 2023 Figure 7. Classification of Acute Aortic Dissection. The DeBakey and Stanford classification systems are used most commonly. The DeBakey system offers greater anatomic detail, whereas the Stanford system is simpler, essentially distinguishing those dissections that involve the ascending thoracic aorta from those that do not. e346 December 13, 2022 Circulation. 2022;146:e334–e482. DOI: 10.1161/CIR.0000000000001106 Isselbacher et al 2022 ACC/AHA Aortic Disease Guideline tions, such as malperfusion or rupture, the mortality rate increases to 20% by day 2 and to 25% by day 30.3 Downloaded from http://ahajournals.org by on November 28, 2023 2.4.1.2. Classification There are 2 commonly used anatomic classification systems for aortic dissection (Figure 7): the DeBakey system and the Stanford system. The DeBakey system categorizes dissections into types I, II, and III, based on the origin of the intimal tear and the extent of the dissection: ● Type I: Dissection tear originates in the ascending aorta and propagates distally to include the aortic arch and typically the descending aorta ● Type II: Dissection tear is confined only to the ascending aorta ● Type III: Dissection tear originates in the descending thoracic aorta and propagates most often distally ○ Type IIIa: Dissection tear is confined only to the descending thoracic aorta ○ Type IIIb: Dissection tear originates in the descending thoracic aorta and extends below the diaphragm The Stanford classification system divides dissections into 2 categories according to whether the ascending aorta is involved or not, regardless of the site of origin: ● Type A: All dissections involving the ascending aorta, irrespective of the site of the intimal tear ● Type B: All dissections that do not involve the ascending aorta (including dissections that involve the aortic arch but spare the ascending aorta) In 2019, the European Association for Cardio-Thoracic Surgery and the European Society for Vascular Surgery published an expert consensus document4 for the treatment of thoracic arch pathologies, in which they added a third category called “non-A-non-B dissection,” to be used for patients whose proximal dissection flap begins in the aortic arch.Most recently, in 2020, the SVS and the STS proposed an entirely new classification scheme that defines the aortic dissection anatomy in more granular detail5: Dissections are defined anatomically according to the location of intimal tears and the proximal and distal extent of the dissection process (Figure 8). AD indicates type A is used for any dissection with an entry tear in zone 0 and extends distally the zone denoted by the subscript D (eg, A9); B PD, type B is used for any dissection with an entry tear in zone 1 or beyond; the proximal and distal extents of the dissection are denoted by subscripts P and D, respectively (eg, B39). I D, when a dissection begins in zone 0 but the location of the entry tear has not been identified, it will be considered “Indeterminate”; it will be designated with an I and its distal extent denoted by the subscript D (eg, I9). 2.4.1.3. Malperfusion Malperfusion syndrome occurs when there is end-organ ischemia related to inadequate perfusion of the aortic branch vessels. The relationship of the true and false lumens in an aortic dissection has a critical role in maintaining stable perfusion of end-organs. Initially, the true lumen collapses because of the loss of transmural pressure across the dissection flap and the subsequent elastic recoil of the medial smooth muscle. Simultaneously, the false lumen expands immediately because of reduced elastic recoil, depth of the dissection plane within the media, and percentage of the wall circumference involved. Circulation. 2022;146:e334–e482. DOI: 10.1161/CIR.0000000000001106 December 13, 2022 e347 CLINICAL STATEMENTS AND GUIDELINES Figure 8. Anatomic Reporting of Aortic Dissection Based on the 2020 SVS/STS Reporting Standards. STS indicates Society of Thoracic Surgeons; and SVS, Society for Vascular Surgery. Reprinted from Lombardi et al.5 Copyright 2020, with permission from Elsevier, Inc., the Society of Thoracic Surgeons, and the Society for Vascular Surgery. CLINICAL STATEMENTS AND GUIDELINES Isselbacher et al 2022 ACC/AHA Aortic Disease Guideline Any of the aortic branches are at risk for malperfusion as the false lumen expands and compresses the true lumen and can occur in multiple vascular beds simultaneously as the dissection propagates distally. Dynamic obstruction occurs when the septum of the dissected intima prolapses across into the ostia of a branch, usually during systole, thereby not allowing adequate flow to perfuse the vessel (Figure 9). The ostia itself remains anatomically undamaged. When the dissection tear extends into the vessel proper and creates a stenosis or thrombosis in the artery, static obstruction occurs (Figure 9). Downloaded from http://ahajournals.org by on November 28, 2023 2.4.2. Intramural Hematoma IMH describes the presence of blood within the medial layer of the aortic wall in the absence of an overt intimal tear or patent false lumen. The blood may arise from either rupture of the vasa vasorum causing bleeding within the media7 or small intimal tears that are not visualized on standard imaging examinations.8 IMH is diagnosed by computed tomographic angiography (CTA), magnetic resonance imaging (MRI), and echocardiography by the presence of a circular or crescent-shaped thickening of the aortic wall of >5 mm in the absence of detectable blood flow9 (Figure 6). Of patients presenting with suspected AAS, studies suggest that 5% to 25% have IMH, a proportion that approaches 30% to 40% in the Asian literature.8-11 The natural history of IMH is variable. Fewer than 10% of IMH cases resolve spontaneously, whereas 16% to 47% progress to aortic dissection if the intimal layer ruptures and creates an entry tear.7,12 2.4.3. Penetrating Atherosclerotic Ulcer A PAU begins with an ulceration of an atherosclerotic plaque, which leads to a focal disruption in the aortic intima that allows blood to penetrate into the medial layer and is often associated with an IMH of variable size.10 PAUs most often appear in the middle or distal descending thoracic aorta, less frequently in the aortic arch and abdominal aorta, and rarely in the ascending aorta.8,10 PAUs can vary in size, and often multiple PAUs are present.10 The true incidence is unknown but is estimated to account for 2% to 7% of all cases of AAS.10 Typically, patients with PAU are older (>70 years of age) than those with classic aortic dissection and present more often with extensive and diffuse atherosclerotic disease involving both the aorta and coronary arteries.10 Additional common comorbidities include hypertension, tobacco use, chronic obstructive pulmonary disease, and renal insufficiency. PAU can occur in younger patients but often in the setting of a connective tissue disorder, and men are more commonly affected than women.8The natural history of PAU is not well defined, as they can remain stable, enlarge, or progress to either IMH, dissection, pseudoaneurysm, or aortic rupture.8 The risk of rupture has been reported to be up to 40%.13 The optimal management strategy must be individualized, e348 December 13, 2022 Figure 9. Mechanisms of Dynamic and Static Obstruction in Aortic Dissection. (A) Static obstruction occurs when the dissection flap extends from the aortic lumen into the ostium of the affected branch vessel, leading to localized thrombosis of the branch false lumen that narrows or colludes the branch true lumen and, consequently, impairs distal branch perfusion. (B) Dynamic obstruction occurs when the false lumen becomes persistently pressurized and compresses the true lumen, in turn pushing the dissection flap up against the ostium of the affected branch vessel, significantly reducing or occluding its flow. (C) Sometimes, a branch vessel can suffer from both static and dynamic obstruction at the same time. Adapted with permission from Grewal et al.6 Copyright 2021, Elsevier, Inc. Circulation. 2022;146:e334–e482. DOI: 10.1161/CIR.0000000000001106 Isselbacher et al 2022 ACC/AHA Aortic Disease Guideline CLINICAL STATEMENTS AND GUIDELINES Downloaded from http://ahajournals.org by on November 28, 2023 Figure 10. Classification of Thoracoabdominal Aortic Aneurysms. The classification of thoracoabdominal aortic aneurysms according to extent of aortic involvement as originally proposed by Crawford is as follows3: Extent I, below the left subclavian to above the celiac axis or opposite the superior mesenteric and above the renal arteries; Extent II, below the left subclavian and including the infrarenal abdominal aorta to the level of the aortic bifurcation; Extent III, below T6 intercostal space, tapering to just above the infrarenal abdominal aorta to the iliac bifurcation; and Extent IV, below T12, tapering to above the iliac bifur