Peripheral Artery Disease: Symptoms, Diagnosis, Treatment

Peripheral Artery Disease Peripheral artery disease (PAD): the blockage of the leg arteries by plaque, leading to gradual narrowing of the arteries in the lower extremities The resulting occlusion leads to a decreased blood flow to the muscles of the leg Severe PAD can lead to amput...

Peripheral Artery Disease Peripheral artery disease (PAD): the blockage of the leg arteries by plaque, leading to gradual narrowing of the arteries in the lower extremities The resulting occlusion leads to a decreased blood flow to the muscles of the leg Severe PAD can lead to amputation Highest prevalence of PAD in 70+ years of age Almost half of PAD patients have intermittent claudication Intermittent claudication: leg pain during exercise due to insufficient oxygen delivery (due to clogged arteries) to meet the metabolic demands of skeletal muscles Common risk factors of PAD: diabetes, hypertension, dyslipidemia, smoking -> damage to arterial lining and inflammation -> PAD Endothelial damage and atherosclerosis result in a stenosis (narrowing of an artery) or blockage of a peripheral artery from: ROS and chronic inflammation Increased BP Hyperglycemia Must slice through the plaque and remove it – angioplasty (PCI – ballooning) and stent Common sites of claudication: Obstruction in: Aorta or iliac artery Femoral artery or branches Popliteal artery or distal Ischemia in: Buttock, hip, thigh Thigh, calf Calf, ankle, foot Focus is down in legs (descending aorta down) Screening tests – imaging pictures -> invasive testing after if positive Signs and symptoms Have most signs/symptoms where the blockage is Patient becomes symptomatic at chronic point of ischemia (intermittent claudication) Intermittent claudication – most common symptom once the disease process reaches a certain point Occurs with physical exertion and diminishes with rest Chronic ischemia is associated with more severe PAD -> presence of ischemia at rest, foot ulcers, gangrene infection (tissue death from lack of blood flow causing amputation consideration) Signs of PAD: Pain in legs with exertion (intermittent claudication) Muscle atrophy Hair loss Smooth shiny skin Skin that is cool to the touch, especially if accompanied by pain while walking Decreased or absent pulses in the feet Nonhealing ulcers or sores in the legs or feet Cold or numb toes Clinical considerations Fontaine stages 1-5 - pain/intensity scale for PAD (based on 200m of walking) Scale used along with RPE during exercise training and testing Diagnostic testing Pressure (hemodynamic) studies BP test – measure at arms and legs Provide functional information Ex: ankle-brachial index, pulse volume recordings Imaging studies  Pictures – CT, MRI Provide anatomic detail Ex; noninvasive assessment – combine ABI with visual ultrasounds If either ABI or NIVA is positive -> CT angiogram/MR angiogram or lower extremity angiogram/catheterization Ankle brachial index – pressure study for diagnosing PAD Assesses arterial circulation Assesses pressure differences between the brachial artery, and dorsalis pedis and posterior tibial arteries using blood pressure cuffs and a doppler probe An ABI significant clinical improvements (build pain tolerance) Walk on treadmill Treadmill testing is useful for assessing claudication onset time or distance and peak walking time or distance ABI is measured before and after the test Abnormal study – ankle pressure drops by >= 20% from baseline or decrease of > 30 mmHg Treatment Very similar to treatment for CAD 1. Medical treatment a. Antiplatelet agents – slows down blood clotting to relieve claudication pain i. Fibrinolytics – catabolizer of fibrous caps ii. Aspirin – inhibits thromboxane A2 production iii. Statins – prevents buildup of atheromas (plaque) 2. Revascularization (surgical bypass, angioplasty-stent, and other endovascular techniques)  a. Surgical bypass – take a graft from other artery and bypass the blocked artery b. Directional atherectomy – removes plaque from blood vessel through a catheter with a rotating blade that slices through plaque or a laser that burns through plaque c. Stents – mimetic; mimics arterial elasticity so they can bend and cause no problem with obstructing blood flow (old conventional stents used to obstruct blood flow if they bent like with the knee bending) 3. Smoking cessation 4. Exercise a. Benefits i. Increased angiogenesis and collateral circulation -> increased blood flow ii. Reduction in blood viscosity – not sticky and won’t form clots iii. Increased pain tolerance – exercise longer without claudication pain iv. Attenuation of new atherosclerotic processes v. Increased amount of walking time vi. Increased amount of pain-free walking time vii. Increased time until feel leg pain with exercise b. Aerobic i. Walking – free or treadmill ii. Initially 30-45 mins (without breaks); gradually work up to 60 mins for up to a year iii. Intensity dependent on onset of claudication 1. Goal: score 3 out of 4 on pain scale (induce claudication to trigger growth of collateral vessels; build pain tolerance) 2. 40-60% HRR iv. 3-5 days/week v. Low-intensity, long duration vi. 6 months+ shows most clinical improvements vii. So, >=30 mins/day, >= 3 days/week, claudication scale of 3-4, > 6 months c. Anaerobic i. Similar to healthy adult guidelines ii. At least 2 days/week iii. 60-80% of 1-RM iv. 2-3 sets of 8-12 reps with all major muscle groups v. Free and machine weights vi. Not substituted for aerobic – aerobic training is primary focus vii. Proper footwear in case wounds on feet  5. Nutrition Statin therapy, atherectomy, aspirin therapy, and walking/cycling at 20-40% HRR are included in initial treatment options for PAD High intensity interval training is not included in initial treatment options for PAD Smoking, a high simple-sugar diet, a high saturated fat diet, and excessive abdominal obesity are known causes of PAD Elevated HDL is not a known cause of PAD The highest brachial SBP should be placed in the denominator for a right leg ABI ABI = ankle/brachial SBP