General Approach to Peripheral Arterial Disease Mahesh Raju MD Advocate Heart Institute
Objectives Identify signs & symptoms of lower extremity peripheral arterial disease (PAD) Significance of early recognition and treatment options for PAD Discuss tests and interventions specific to arterial disease Describe pharmacologic therapies for treatment of arterial disease Describe when endovascular treatment is an option
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Peripheral Arterial Disease Vascular disease caused primarily by atherosclerosis & thromboembolic pathophysiological processes that alter the normal structure and function of the aorta, its visceral arterial branches, and the arteries of the lower extremities
Prevalence of PAD Very common Increasing incidence with age 20% of people over age 70 have PAD 5% of people over age 40 have PAD Prevalence of PAD: 11 Million, compared to stroke: 4.4 Million, and MI: 7 Million Progressive disease in 25% with progressive intermittent claudication/limb threatening ischemia Outcomes Impaired Quality of Life Limb Loss Premature Mortality
PAD and Mortality
Survival for PAD patients IC: intermittent claudication CLI: critical limb ischemia J Vasc Surg 2007;45,Suppl S Overall Mortality Rate: Claudicant patient 2.5 x Survival for PAD patients
Mortality / Morbidity About 5% of PAD patients will need treatment for limb related issues 25% will die within 5 years from other causes such as cardiac, cerebral, or other vascular events Aronow, 1994
Risk Factors Race: Non-Hispanic blacks (2x) Gender: Male 2:1 Age: > 65 (2x) Smoking (3x) Diabetes mellitus (4x) Hypertension Dyslipidemia (2x) Chronic renal insufficiency J Vasc Surg 2007; 45, Suppl S
Risk Factors: Framingham Heart Study Reduced Increased Smoking Diabetes Hypertension Hypercholesterolemia Hyperhomocysteinemia Fibrinogen Mean follow-up 38 years C- Reactive Protein Alcohol Relative Risk.5 1 2 3 4 5 6
Clinical Presentation Asymptomatic Claudication Critical limb ischemia Acute limb ischemia Prior revascularization
Typical vs Atypical Symptoms Typical Symptoms 1 Intermittent claudication Exertional calf pain that causes the patient to stop walking resolves within 10 minutes of rest Other nonspecific leg symptoms that may be indicative of PAD Atypical Symptoms 1 Exertional leg pain that may involve areas other than the calves may not stop the patient from walking may not resolve within 10 minutes of rest 33% 2 >50% 2 1. McDermott MM et al. JAMA. 2001;286:1599-1606. 2. Hiatt WR. N Engl J Med. 2001;344:1608-1621.
Femoral & Popliteal arteries: 80-90% Tibial & Peroneal arteries: 40-50% Aorta & Iliac arteries: 30% Harrison s Principles of Int Med
Rutherford Classification Stage Stage Clinical Claudication 0 Asymptomatic 1 Mild claudication 2 Moderate claudication 3 Severe claudication 4 Ischemic rest pain Critical limb ischemia 5 Minor tissue loss 6 Major tissue loss Rutherford RB, et al, J Vasc Surg 1986;4:80-94
Critical Limb Ischemia Resting ischemic pain PAD with skin breakdown Nonhealing ulcers Gangrene
Rutherford 4 Ischemic rest pain Rutherford 5 Minor tissue loss Rutherford 6 Major tissue loss
Spectrum of Peripheral Arterial Disease Claudication Limb-Threatening Ischemia "Normal Fatigue, Heaviness Mild Moderate- Severe Rest pain Poor wound healing Impending or overt gangrene Worsening flow limitation
History and Physical Leg pain, particularly when walking or exercising, which disappears after a few minutes of rest Numbness, tingling, or coldness in the lower leg or feet Sores or infection on feet or legs that heal slowly Many patients/family think it is a part of normal aging
PVD Differential Diagnosis Deep venous thrombosis Musculoskeletal disorders OA Restless leg syndrome Peripheral neuropathy Spinal Stenosis (pseudoclaudication) Better by sitting or lying down. Can find relief by leaning forward and straightening the spine
Intermittent Claudication Intermittent claudication A reproducible discomfort that is induced by exercise and relieved with rest. Supply Demand Location depends upon the location of the disease. Buttock, thigh, calf or foot claudication, either alone or in combination.
Differential Diagnosis of Intermittent Claudication Intermittent Claudication Venous Claudication Neurogenic Claudication Quality of pain Cramping "Bursting" Electric shock-like Onset Gradual, consistent Gradual, can be immediate Can be immediate, inconsistent Relieved by Standing still Elevation of leg Sitting down, bending forward Location Muscle groups (buttock, thigh, calf) Whole leg Poorly localized, can affect whole leg Legs affected Usually one Usually one Often both
Location Buttock/hip Usually indicates aortoiliac occlusive disease Thigh Occlusion of the common femoral artery leads to claudication in the thigh, calf, or both. Calf Symptoms in upper 2/3 is usually due to SFA Lower 1/3 is due to popliteal disease.
PVD History Asymptomatic patients with abnormal ABI have 50% increased risk of cardiovascular complications Very important part of diagnosing the condition Hirsch AT, et al. JAMA 2001; 286: 1317 Hooi JD, et al. J Clin Epidem 2004; 57:294
Physical Exam Trophic Signs Skin atrophy, thickened nails, hair loss, dependent rubor Ulceration, gangrene Pulse exam May miss more than 50% Criqui M, et al. Circulation, 1985: 71; 516-521
Arterial Pulse Exam 0 = absent pulse 1 = faint, but detectable 2 = reduced can count pulse 3 = normal pulse 4 = bounding
Diagnostic Modalities Ankle-Brachial Index (ABI) Toe Brachial Index (TBI) Segmental pressure measurement Pulse volume recording Ultrasound: CW and duplex Exercise treadmill, 6 minute walk test
Ankle Brachial Index (ABI)
Ankle-Brachial Index Values and Clinical Classification Clinical Presentation ABI Normal > 0.90 Claudication 0.50-0.90 Rest pain 0.21-0.49 Tissue loss < 0.20 Values >1.25 falsely elevated; commonly seen in diabetics Am J Cardiol 2001; 87 (suppl): 3D-13D NEJM 2001; 344: 1608-1621
Ankle Brachial Index (ABI) ABI= Right Arm Pressure 136 mm Hg Lower extremity systolic pressure Highest brachial artery systolic pressure Left Arm Pressure 140 mm Hg Highest Right Pedal Pressure 154 mm Hg Highest Left Pedal Pressure 54 mm Hg Right ABI 154/140= 1.1 Left ABI 54/140 = 0.4
Limitations Noncompressible vessels Diabetes Renal Failure ABI >1.5 Use toe-brachial index Normal >0.7 Rest pain <0.2 Subclavian/Brachiocephalic Occlusive disease
Survival is directly related with ABI severity J Vasc Surg 2007;45 Suppl S:5A
Duplex in SFA Disease
Doppler Waveform Analysis: Hemodynamic Information 95% accuracy in the detection of bypass graft stenosis, but can overestimate stenosis. Polack JF. Duplex Doppler in peripheral arterial disease. Radiol Clin N Amer 1995; 33 : 71-88.
Arterial Vascular Study Doppler Waveform Normal Doppler Arterial Signal Triphasic Biphasic Abnormal Doppler Arterial Signal Reduced Bi. Monophasic Absent
Radiologic Imaging: MRA and CTA Reserved for planning interventions Identifies location and severity of disease Duplex is still used as a first line modality
DSA vs. MRA
MRA: Current Technique 3D gradient echo Gadolinium Enhanced 20-40 cc Renal arteries to toes Stepping table or bolus chase 45-min exam
Limitations of MRI Uncooperative patient Claustrophobia Metal artifact Pacemakers/ICDs Lack of visualization of calcium
CTA of PVD Multidetector CT scanner Iodinated contrast volume similar to angiography 80-150 cc 20-minute exam High powered post processing software needed
CTA of PVD
CT Limitations With significant and dense calcifications, a false diagnosis of patency can result. Uncooperative patient Pregnancy Decreased EF Inconsistent pedal vessel visualization Renal failure/contrast allergy
Digital Subtraction Angiography (DSA) Gold standard of arterial imaging Compares a pre contrast image with a post contrast image using a computer, and "subtracts" elements common to both. Bone eliminated Radiation exposure and contrast volumes are lower than conventional angiography Interventional procedures can be performed Images reviewed and stored
Digital Subtraction Angiography (DSA) Not a screening test: Technique is invasive Requires arterial puncture Longer study than CT Contrast nephrotoxicity
Treatment Goals Relieve symptoms and improve walking ability Improve quality of life Reduce total mortality along with both cardiac and cerebrovascular morbidity and mortality
Cardiovascular risk reduction Lipid lowering drugs Antihypertensive drugs Diabetes therapies Smoking cessation Antiplatelet drugs
Claudication Exercise and lower extremity PAD rehabilitation Exercise program Improves walking ability Needs motivation Needs to be maintained Pharmacological treatment Cilostazol Pentoxifylline
Revascularization Severe claudication not improved with risk factor or medical control Limb-threatening ischemia pain at rest non healing ulcers infections / gangrene
Treatment Approach to Intermittent Claudication Assess severity of claudication Mild to moderate claudication Severe claudication Exercise & drug therapy Symptoms Symptoms improve debilitating Continue present therapy Aortoiliac or femoral dz Consider percutaneous intervention Localize lesion Popliteal-tibial dz Exercise & drug therapy unless debilitating
Poor Invasive or Surgical Candidate Medical comorbidity Lack of suitable outflow vessel Patient preference
Rogers, J. H. et al. Circulation 2007;116:2072-
Iliac Artery Intervention
SFA Intervention
Infrapopliteal Intervention for CLI
PAD Summary PAD is common disorder and has a significant impact upon cardiovascular outcomes Treatment, even if asymptomatic, should focus on risk factor modification/risk reduction Treatment of intermittent claudication should include a combination of exercise therapy, drug therapy and selective use of revascularization Treatment for critical limb ischemia needs aggressive efforts at revascularization to reduce the risk of amputation