CMS200 - Week 10

Peripheral Arterial Disease Module (CMS200)

• This module covers Peripheral Arterial Disease (PAD), Peripheral Vascular Disease (PVD), and Atherosclerosis.
• Learning outcomes include evaluating definitions, epidemiology, and presentation of PAD, PVD, and Atherosclerosis, including claudication and critical limb ischemia.
• Understanding prevalence in different populations and the impact of factors like age, ethnicity, and comorbidities on disease prevalence is also crucial.
• Analysis of risk factors for PAD and PVD, including smoking, diabetes, hypertension, hyperlipidemia, and chronic kidney disease, are key.
• Performing a comprehensive clinical history, review of symptoms, and physical examination, including skin examination, pulse examination, and grading peripheral pulses, is important for assessment.
• Analyzing the use, interpretation, and limitations of diagnostic tests like the ankle-brachial index (ABI), Doppler studies, CT angiography, MRA, and ECG for evaluating PAD and PVD is also covered.
• Investigating the importance of early detection, differential diagnosis, and the association between PAD, PVD, and other vascular diseases is vital.

Atherosclerosis: Epidemiology

• Atherosclerotic vascular disease is a major cause of morbidity and mortality worldwide.
• It's a leading cause of cardiovascular diseases and the most common, serious, and clinically relevant form of arteriosclerosis.
• Arteriosclerosis is a general term for disorders causing thickening and loss of elasticity in arterial walls.
• Atherosclerosis affects all large and medium-sized arteries, including coronary, carotid, cerebral, aorta, and major arteries of the extremities.
• Incidence is rapidly increasing in low and middle-income countries, correlating with longer lifespans.

Atherosclerosis: Epidemiology (continued)

• Atherosclerosis is primarily asymptomatic.
• Ischemic heart disease (IHD) and ischemic stroke are the first and fifth leading causes of death respectively, and major causes of long-term disability in adults in the US.
• In the US, 1 in 4 deaths is attributed to cardiovascular diseases.
• Atherosclerotic stenosis of the internal carotid or intracranial arteries can cause up to 15% of strokes.
• Peripheral artery disease affects one in five people aged 60+ years old in the US, and nearly half of those aged 85+.
• Renal artery stenosis can impact up to 5% of people with isolated hypertension and up to 40% of individuals with other atherosclerotic diseases.

Atherosclerosis: Demographics

• 75% of acute myocardial infarctions originate from plaque ruptures.
• Incidence is higher in men over 45 and women over 50.

Atherosclerosis: Risk Factors

• Modifiable risk factors include dyslipidemia (elevated LDL), hypertension, tobacco smoking, diabetes mellitus, and obesity.
• Non-modifiable risk factors include age and gender (lower estrogen mediated atheroprotection and lower HDL, higher LDL and lower estrogen) and heredity.
• Other risk factors include chlamydia pneumoniae infection, elevated levels of homocysteine, and lipoprotein-A (Lp(a)).

Atherosclerosis: Symptoms

• Symptoms depend on the affected arteries and the extent of blockage.
• Coronary heart disease presents with angina (chest pain), cold sweats, dizziness, tiredness, heart palpitations, shortness of breath, nausea, and weakness.
• Peripheral artery disease (PAD) symptoms include pain, aching, heaviness, or cramping in the legs during walking or climbing stairs, often relieved by rest.
• Vertebral artery disease (TIA) can manifest with memory issues, weakness/numbness on one side of the body/face, and vision problems.
• Mesenteric artery ischemia causes severe pain after meals, weight loss, and diarrhea.

Atherosclerosis: Signs (Physical Examinations)

• Physical examinations are important in assessing atherosclerosis. They include checking blood pressure, peripheral pulses, carotid or abdominal artery bruits, abdominal palpation, cardiovascular and peripheral vascular exams, respiratory exams and skin exams for xanthomas.

Atherosclerosis: Further Testing

• Laboratory tests include lipid profile (LDL-cholesterol), plasma glucose, and high-sensitivity C-reactive protein (hsCRP).
• Imaging tests include ultrasound of the abdomen to screen for abdominal aneurysms, Doppler device to measure the ankle-brachial index (ABI), sonography of the carotids, electrocardiogram (ECG), stress ECG, and electron beam computed tomography (EBCT).
• Angiography is a primary method for imaging atherosclerotic lesions in the coronary circulation, primarily used in high-risk patients with symptoms, and not a routine screening test.
• Computed tomography (CT) angiography is used in assessing ASCVD, detecting low-attenuated plaques, and predicting acute coronary events.
• Cardiovascular magnetic resonance imaging (cardiac MRI) is another imaging option, but is more expensive.

Atherosclerosis: Complications

• Occlusion of a blood vessel depends on which organ isn't getting adequate blood flow.
• Plaque disruption can cause hemorrhage or thrombus formation (a blood clot).
• Emboli (pieces of plaque) can travel farther down the vessel, potentially causing blockages.
• An aneurysm occurs when the wall of an artery weakens and dilates, increasing risk of rupture and hemorrhage.
• Peripheral vascular disease includes claudication (ache or cramping in extremities during exertion, relieved by standing still), cool extremities, diminished distal pulses, shiny/hairless skin and ischemic ulcerations.

Atherosclerosis: Clinical Course

• Complications of atherosclerotic cardiovascular disease (ASCVD) include coronary artery disease (CAD), cerebrovascular disease (CVA), transient ischemic attacks (TIA), peripheral artery disease (PAD), abdominal aneurysms, and renal artery stenosis.
• Prognosis can be good with management of risk factors such as LDL cholesterol with statin therapy, blood pressure control, diabetes management, smoking cessation, regular exercise, and dietary changes.
• Worse prognosis is linked with end-organ disease such as heart failure, stroke, and rupture of an abdominal aneurysm.

Atherosclerosis: Healthcare Teams

• All healthcare professionals should promote prevention.
• Patients should be educated on regular exercise, smoking cessation, and maintaining a healthy weight and diet.
• Use appropriate medications for lipid control when indicated.
• Manage risk factors like elevated LDL-C, blood pressure, diabetes, and obesity through medications (statins, antihypertensives, etc.).
• Patients should be instructed to exercise and eat a healthy diet including minimizing saturated and trans fats, reducing salt intake, increasing consumption of monounsaturated fats, fatty fish, fruits, and vegetables, and maintain a healthy weight.
• Smoking cessation is paramount.
• Consider revascularization procedures where appropriate (angioplasty, bypass).

Peripheral Vascular Disease (PVD)

• An overarching term encompassing vascular diseases resulting from circulatory dysfunction. This may affect blood vessels outside the heart (including arteries, veins, and lymphatic vessels).
• Most common PVD types are peripheral artery disease (PAD), chronic venous insufficiency (CVI), and deep vein thrombosis (DVT).
• A major driver is progressive atherosclerotic disease, leading to reduced organ blood flow and end-organ ischemia.

Peripheral Arterial Disease (PAD)

• PAD is a chronic, progressive atherosclerotic disease in the peripheral vascular circulation.
• It involves the blockage of major arteries distal to the aortic arch, particularly affecting the lower extremities, but can occasionally affect the upper extremities.
• Progressive occlusion leads to arterial stenosis, reduced blood flow, and claudication.

PVD/PAD Epidemiology

• American Heart Association estimates 8-12 million Americans have PAD (3-10% prevalence).
• Prevalence increases significantly with age (nearly 50% in those ≥85 yoa,29% in those ≥70).
• PAD and PVD prevalence in those >70 yoa range 15-20%.
• Risk factors include increasing age, male gender, and racial/ethnic disparities (e.g., African Americans having a 2.12 odds ratio for PAD).
• Socioeconomic factors such as lower poverty-income ratios and lower educational level are also related to PAD risk.

PVD/PAD Risk Factors

• Risk factors for PAD and PVD include advanced age, male gender, positive family history, history of coronary artery disease, sedentary lifestyle, cigarette smoking, diabetes, hypertension, and hyperlipidemia.
• Studies show 80% of PAD patients are current or former smokers, significantly increasing PVD risk.
• Cardiovascular mortality is significantly higher in current smokers with PAD.

PVD/PAD: Symptoms (Claudication)

• Classic claudication is characterized by fatigue, muscle discomfort, cramping, or pain in the lower limbs (often calves/buttocks).
• Symptoms are consistently brought on by exercise (especially walking a set distance), and relieved by rest within 10 minutes.
• Approximately 42% of patients with PAD are asymptomatic, while 47% have atypical, non-classical symptoms of leg pain.

PVD/PAD: Non-specific Symptoms/Findings

• Additional non-classical symptoms include (but aren't limited to) leg pain or sensations, skin/hair/nail changes, non-healing wounds, and edema.
• Symptoms are also associated with coldness in the lower legs/feet, changes in leg color/texture/temperature, slow toenail growth, fatigue, burning/numbness/tingling in the legs.

PVD/PAD: Diagnostic Tools (Edinburgh Claudication Questionnaire)

• Used to reliably identify intermittent claudication in symptomatic patients.
• The Questionnaire consists of six self-administered questions and a pain diagram.
• It has a high specificity (91%) and sensitivity (99%).

Case: Mr. T. with Leg Pain

• A case study of a 65-year-old male presenting with progressive leg pain, worse with walking and better with rest
  • Onset 6 months ago
  • Increasingly affects daily activities like walks with friends.
• Requires further investigation to ensure an accurate and informed diagnosis.

PAD: Physical Examination

• Evaluate blood pressure
• Assess gait and walking function (presence of claudication); ischemic rest pain.
• Inspect skin on the lower extremities; checking for non-healing wounds (ulcers), arterial ulcerations (well-demarcated "punched out" lesions).
• Inspect for ulcers between toes (kissing ulcers) and/or ulcers from ill-fitting shoes.
• Examine for lower extremity gangrene
• Look for perfusion (color changes when legs are raised, dependent rubor, and pallor with elevation).
• Palpate for pulses (grade noted) checking for decreased pulses.
• Auscultate for vascular bruits (aortic, carotid, femoral, iliac and popliteal).

PAD: Further Testing – Additional Diagnostics

• Complete blood count (CBC) with platelet count
• Electrolytes
• Fasting glucose
• Fasting lipid profile
• Kidney function tests (including serum creatinine)
• Urinalysis checking for glucosuria and proteinuria
• Ultrasound of the abdomen for detecting abdominal aneurysms
• Doppler devices
• Ankle Brachial Index (ABI)
• Carotid ultrasound
• ECG
• Stress ECG
• EBCT (electron beam computed tomography)
• Magnetic resonance angiography (MRA)/computed tomography angiography (CTA).
• Catheter-based angiography
• Transcutaneous oximetry

Critical Limb Ischemia (CLI)

• Is the severe manifestation of PVD/PAD (1-2% of PVD/PAD patients).
• Occurs with intermittent claudication in about 21%
• Develops through gradual ischemic conditioning (promoting collateral vessels) that maintain limb perfusion.
• Risk factors include diabetes, renal failure, heart failure, and prior stroke.
• Risk for limb loss (chronic limb threatening ischemia).

Critical Limb Ischemia (CLI): Symptoms

Symptoms include chronic (more than two weeks of):

• Ischemic rest pain.
• Ischemic wounds.
• Tissue loss.
• Gangrene (in one or both legs)
• Nocturnal/ischemic rest pain worsening when supine.
• Painful toes/forefoot/calves (complemented by cramping, coldness, numbness/pain).
• Relief of symptoms by dangling legs over the side of the bed (relieving dependent rubor).

Acute Limb Ischemia (ALI)

• Abrupt interruption of arterial blood flow to an extremity.
• Symptoms include coldness, pain, pallor, diminished/absent pulse, motor/sensory impairment.
• ALI threatens limb integrity without prompt revascularization (medical emergency).

Acute Limb Ischemia (ALI): Differential Diagnosis

• Congestive heart failure (CHF): superimposed on chronic arterial disease (pain, pallor, paresthesia, paralysis).
• Deep vein thrombosis (DVT): acute (painful, bluish/swollen leg with absent pulses).
• Acute spinal cord compression (pain, paraesthesia, paralysis, normal skin color and pulse).

PVD - Laboratory Screening

• Complete blood count (CBC) with platelet count
• Electrolytes
• Fasting glucose or A1C
• Fasting lipid profile
• Kidney function tests (including serum creatinine)
• Urinalysis for glucosuria and proteinuria

PVD/PAD: Further Investigations

• Duplex ultrasound/Doppler ultrasonography: cost-effective method of determining PAD location, stenosis severity/length or occlusion.
• Sensitivity/specificity depend on calcium presence in arterial wall, vessel location/depth, and the presence of multiple occlusions.
• Doppler ultrasonography is for post-procedure surveillance.

PVD/PAD: Further Investigations – Advanced Imaging

• Magnetic resonance angiography (MRA) or computed tomography angiography (CTA): excellent high-quality vascular imaging (used for diagnosis for bypass surgery versus angioplasty)
• Sensitivity/Specificity is 90-100% in detecting PAD
• MRA helps identify small runoff vessels.
• Digital subtraction angiography (DSA) used to determine lesion localization and when invasive or surgical intervention is needed.
• Catheter-based angiography (gold standard) and Transcutaneous oximetry (assessing perfusion in patients with ulcers).

Venous Thromboembolism (VTE)

• Includes deep venous thrombosis (DVT) and pulmonary embolism (PE).
• One-third of patients with VTE experience recurrence within 10 years.
• VTE is the third most common life-threatening cardiovascular disease in the US, after myocardial infarction (MI) and stroke.
• Causes cardiovascular death, chronic disability, and emotional distress (especially post-thrombotic syndrome and venous ulcers).

Venous Thrombosis (DVT)

• Blood clot forms in a deep vein, most often in the leg.
• Symptoms include (but aren't limited to) pain, swelling, warmth, and redness in the involved extremity.
• Coexists with other conditions: trauma, infection, peripheral artery disease, and other venous processes.

Pulmonary Embolism (PE)

• Blood clot (from DVT) breaks off and travels to the lungs.
• Symptoms are often clinically silent.
• May be associated with significant morbidity/mortality, with significant morbidity presented by decreased cardiac output, oxygenation deficit hypoxia), and increased risk of right-to-left shunting.
• Most common symptoms: . Dyspnea, pleuritic chest pain, • Tachypnea, • Cough, • Syncope.

Abdominal Aortic Aneurysm (AAA)

• A degenerative disease of the aorta
• Defined by the expansion of the vessel diameter by more than 50%.
• Characterized by inflammation and arterial wall degradation, potentially leading to dilatation and rupture.
• Prevalence increases with age, particularly in those older than 75.
• Symptoms may be asymptomatic until rupture or rapid expansion, presenting with severe abdominal pain radiating to the back.
• Abdominal aortic aneurysm screening with ultrasonography is reasonable for symptomatic PAD or a significant abdominal mass.

PVD/PAD: Clinical Course (Overview)

• Patients experience varying clinical courses (asymptomatic, intermittent claudication, critical leg ischemia, and death (cardiovascular morbidity/mortality)).
• Significant risk factors are the primary drivers for disease progression and complications.
• Outcomes including major amputation, cardiovascular events, and mortality are influenced by initial PAD presentation.
• Five-year prognosis shows most patients with PAD are stable with fewer progressing to significant complications like rest pain, other cardiovascular problems, and death.

PVD/PAD: Prognosis & Complications

• Short-term/long-term complications may include ischemia/gangrene, amputation, infection, ulceration, coronary artery disease, myocardial infarction, stroke, blood clots, erectile dysfunction, and/or depression.

PVD/PAD: ABI Testing and Prognosis

• Repeated ABI testing with functional status changes warrants further testing or clinician referral.
• An ABI score of <0.9 is strongly correlated with a 2-4 times higher risk of cardiovascular events and overall mortality.
• Low ABI is 92.7% specific for predicting incident coronary heart disease, with 20% of patients experiencing a nonfatal myocardial infarction in five years, and 15-30% of patients experiencing cardiovascular deaths.

PVD/PAD: Prognosis (Patient Studies)

• Studies from Scotland show higher mortality rates in PVD patients compared to control groups (3.8% PVD with claudication, 6.1% PVD without claudication symptoms, compared to 2.0% in the control group).
• Five-year prospective study (n=1,592) with PVD noted higher mortality for those with claudication.
• No evidence shows that early identification significantly reduces mortality/morbidity in PAD patients.

Table 1 - Risk Index for 10-Year Mortality in PAD Patients

• A validated prognostic index to stratify long-term mortality risk.
• Various risk factors for PAD (renal dysfunction, heart failure, age, hypercholesterolemia, ST/ECG changes, Ankle-brachial index, cerebrovascular disease, diabetes mellitus, and pulmonary disease, use of statin/aspirin/beta blockers) assign specific points.

PVD/PAD: Treatment Considerations (General)

• Ensure patients are not on vasoconstricting medications.
• Educate patients regarding foot hygiene and protective footwear.
• Educate patients on PAD/PVD signs and symptoms to identify changes immediately.
• Consider medication guidelines, such as statins and/or aspirin or cilostazol, in addition to lifestyle modifications.
• Surgical revascularization is indicated for patients with claudication symptoms not responding to other interventions and may be considered as an option in patients with critical limb ischemia.

PVD/PAD: Treatment Considerations (Prevention)

• Lifestyle changes are key to preventing/slowing progression of PVD.
• Smoking cessation is particularly crucial.
• Maintain healthy weight, control blood sugar/blood pressure/cholesterol.
• Encourage regular exercise, to improve walking capacity, in PAD patients.
• Consider aspirin as part of preventative measures.
• Use appropriate dietary modification and lipid lowering agents, as needed, to minimize cholesterol.
• Aggressive blood pressure reduction is important.

Summary

• Comprehensive evaluation of atherosclerosis, PAD, and PVD, including definitions, epidemiology, risk factors, and presentations (particularly claudication and critical limb ischemia).
• Analysis of various diagnostic tools, including ABI, Doppler studies, CT angiography, MRA, transcutaneous oximetry, and ECG, and their limitations/interpretations, was undertaken.
• Identification of comorbid presentations like abdominal aneurysms, intermittent claudication, and venous thromboembolism (VTE).
• Study of disease progression/complications (including those involving ischemia, amputation, infection, ulceration, coronary artery disease, stroke, blood clots, erectile dysfunction, and potentially depression).
• Evaluation of prognostic factors (detailed in Table 1) and prediction of 10-year mortality risk.
• Management options and treatment considerations including lifestyle changes (including smoking cessation, weight management, diet, blood sugar/lipid/blood pressure control, and regular exercise), and interventions like surgical revascularization in specific cases, or emergent consultation.
• Review references for further information.

Test your knowledge on cardiovascular health, focusing on atherosclerosis, its effects, and associated conditions. This quiz covers morbidity, mortality, and the assessment of Peripheral Arterial Disease. Assess how various risk factors impact heart conditions and their prevalence in different demographics.