Introduction to Peripheral Arterial Disease Stacey Clegg, MD Interventional Cardiology August 20 2014
Outline (and for the ABIM board exam * ** ***) Prevalence* Definitions Lower Extremity: Aorta*** Claudication*** Critical Limb Ischemia (CLI)*** Acute Limb Ischemia (ALI)* Carotids** Diagnosis Non invasive testing*** When to refer to a vascular specialist** Peripheral Vascular Anatomy Treatment Medical Therapy*** Interventional Therapy
Peripheral Arterial Disease PAD is the preferred clinical term used to denote Stenotic, occlusive, and aneurysmal disease Of the aorta and its branch arteries Exclusive of the coronary arteries Domains Carotid/Vertebral/Subclavian Aortic Renal/Mesentery Lower Extremity Hirsch AT, et al. Circulation. 2006;113:e463-654
Aortic Aneurysms**
Screening for AAA Men aged 65-75 who have ever smoked should undergo a one time screening abdominal ultrasound (AHA/ACC Class IIA, USPSTF) Men aged 60 or older who have a sibling or parent with a history of AAA should have a physical exam and ultrasound screening for AAA (AHA/ACC Class I)
When to refer for AAA repair? AAA > 5.5 cm = REPAIR AAA 4-5.4 cm = abdominal u/s or CT scan q 6 months to 1 year to monitor for enlargement
Board Question 1 A 68 yo male smoker presents to the ED with 1 day of lower back pain. He has a regular PCP and underwent screening ultrasound for AAA at age 65 and was found to have a 4.0 cm infrarenal aneurysm. On exam he is uncomfortable. His blood pressure is 85/40 with a HR of 110. His distal pulses are easily palpable and LE are warm. His abdominal exam is difficult due to obesity but you hear a bruit and suspect a pulsatile mass. What is the next best step? A. Contrast CT of the abdomen and abdominal aorta B. Beta Blocker administration C. Vascular surgery consultation D. Narcotics for back pain and follow up with PCP in 1 week.
Symptomatic AAA = EMERGENCY REPAIR Endovascular vs Open Triad of hypotension, back pain, pulsatile mass are buzz words for emergent surgical evaluation regardless of the size of the aneurysm
Aortic Dissections***
Carotid Artery Disease
Board Question A 65 yo smoker presents to your office for a new patient visit. On exam you note a left carotid bruit. A routine ultrasound with Doppler is ordered and reports a 100% occluded right internal carotid artery and a 40% stenosis of the left internal carotid artery. What do you recommend to reduce the risk of a future stroke? 1. Refer to vascular specialist for revascularization of the left carotid artery B. Refer to vascular specialist for revascularization of the right carotid artery C. Check lipid panel and prescribe atorvastatin and aspirin D. Order an exercise stress test because his risk of concomitant CAD is very high
Screening USPTF does NOT recommend routine screening for carotid disease Detection of an asymptomatic bruit should prompt initiation of medical therapy for CAD/PAD risk factors
Carotid Disease: Asymptomatic vs Symptomatic Symptomatic Carotid disease: TIA or a stroke (symptoms contralateral to side of the carotid stenosis) Amaurosis Fugax: Vision loss ipsilateral to side of carotid disease Emergent/Urgent vascular referral for stenting or surgery Symptomatic carotid disease is usually EMBOLIC
Carotid Disease Asymptomatic 60% by ultrasound/doppler refer to vascular specialist Less than 60% can be treated with risk factor modification All patients should be on ASA and a statin
Carotid Disease Summary If carotid disease is found, institute medical therapy for CAD/PAD with ASA statin Symptomatic carotid artery disease warrants urgent revascularization Asymptomatic disease is more tricky refer to specialist for >60% stenosis Never revascularize 100% occlusions
Lower Extremity
Natural History and Prognosis CV Risk cardiovascular events cerebrovascular events Lower Extremity Symptoms Claudication Critical Limb ischemia Acute limb ischemia functional capacity
Claudication: Definition Discomfort, cramping or aching in the calves, buttocks or thighs that is reproducible with exertion and relieved with rest
Critical Limb Ischemia (CLI) Rest Pain Non healing ulcers Gangrene
Board Question 2 A 78 yo male with a history of CABG in 1999 and ongoing smoking presents to your office for routine follow up. He has recently started cardiac rehab after PCI to the SVG to OM during a hospitalization for NSTEMI. He has no symptoms of angina since PCI. He states that he has a feeling of burning in his left calf extending to the L thigh during rehab sessions that goes away with rest. Physical exam shows no evidence of lower extremity wounds and the feet are warm with normal capillary refill. What is the most appropriate next step in this patients management?
Board Question 2 Continued A. Referral to vascular surgery B. Referral to interventional cardiology C. Lower Extremity arterial ultrasound with Doppler D. Ankle Brachial Index E. Exercise Stress Test
Acute Limb Ischemia 4 P s: Pallor, Pain, Parasthesias, Pulseless Arterial clot is usually due to an Embolic event (THINK AFIB) or HYPERCOAGULABLE DISORDER or loss of a lower extremity bypass graft Vascular emergency
Claudication vs CLI Treatment and Prognosis very different CLI: Prognosis at 1 yr: Alive with two limbs 50% Amputation 25% Cardiovascular mortality 25% Treatment is aimed at limb salvage, includes aggressive revascularization Claudication: Prognosis at 5 years: 70% will have stable claudication 30% will have a cardiovascular event or death Treatment aimed at symptoms and risk factors
Claudication: Sites of Obstruction Buttock & Hip Claudication ±Impotence Leriche s Syndrome Thigh Claudication Calf Claudication Foot Claudication
Comprehensive Vascular Examination Key components of the vascular physical examination include: Bilateral arm blood pressure (BP) Cardiac examination Palpation of the abdomen for aneurysmal disease Auscultation for bruits Examination of legs and feet Pulse Examination Carotid Radial/ulnar Femoral Popliteal Dorsalis pedis Posterior tibial Scale: 0=Absent 1=Diminished 2=Normal 3=Bounding (aneurysm or AI) Ankle Brachial Index (ABI)
Board Question What is a normal ABI? A.) 0.8-1.0 B.) 0.90-1.29 C.) 0.9-1.20 D.) 0.8-1.29
Ankle Brachial Index Why should we care? In clinical practice Aids in diagnosis and assessment of patients with symptoms suggestive of PAD Role in primary prevention since PAD is a powerful independent predictor of CV morbidity and mortality regardless of symptomatic status of PAD.
Peripheral Arterial Disease: ABI: Impact of Diagnosis on Survival Resnick et al. Circulation 2004;109;733-739
Severity of PAD and Survival 100 Survival (% of patients) 80 60 40 ABI >0.85 ABI 0.4-0.85 ABI <0.4 20 0 2 4 6 8 10 Year ABI = ankle-brachial index, PAD = peripheral arterial disease. McKenna M et al. Atherosclerosis. 1991;87:119-128.
Ankle Brachial Index Performance Calculation Interpretation
Ankle Brachial Index Performance - Equipment
Ankle Brachial Index Performance - Review Patient Position No activity for 4-5 minutes Supine position
Ankle Brachial Index Performance Arm Pressure Arm Appropriate cuff size Doppler over brachial artery NOT STETHESCOPE (underestimate SBP) Record right AND left arm brachial pressures Why?
Ankle Brachial Index Diagnosis of PAD 90 80 70 60 50 40 30 20 10 0 Sensitivity Specificity Accuracy Niazi et al, Cath Cardiovasc Interv 2006;68:788-792
Ankle Brachial Index Calculation - Rationale Patient DP 100, PT 150, Highest brachial 150 Method 1. Higher of the two pressures ABI 150/150 = 1 Sensitivity Specificity Method 2. Lower of the two pressures ABI 100/150 = 0.66 Sensitivity Specificity
Ankle Brachial Index Interpretation What is a normal ABI?
Ankle Brachial Index Interpretation Normal ankle pressure is 8-15% higher than arm pressure Epidemiological studies have used ABI of 0.9 as cutoff of normal from abnormal for diagnosis of PAD.
Interpreting the Ankle-Brachial Index ABI Interpretation 0.90 1.29 Normal 0.41 0.90 Abnormal 0.40 Severe disease 1.30 Noncompressible Adapted from Hirsch AT, et al. J Am Coll Cardiol. 2006;47:e1-e192. Figure 6.
Other Non Invasive Diagnostic Tests Segmental Limb Pressures Pulse Volume Recordings Doppler/Lower Extremity ultrasound CTA angiography MR Angiography
Suspected PAD Clinical Assessment Non Invasive Evaluation ABI Segmental Limb Pressures Doppler PVRs PAD Likely PAD Unlikely If intervention considered: Ultrasound with Doppler CTA MRA Diagnostic Angiography Surgical Treatment Angiography Conservative Treatment Endovascular Treatment
ABI and Localization of Disease Segmental Limb Pressures Brachial Thigh Aorto iliac disease SFA disease Calf Tibial disease Ankle Toe Small Vessel disease (normal TBI: 0.8-0.9) Toe pressure in claudicants 60-70mmHg, CLI <30mmHg)
Doppler Waveforms
Doppler Waveforms
When to refer to a vascular specialist? Any patient with a history of typical or atypical claudication symptoms Any patient with an abnormal ABI Any patient with non healing lower extremity wounds or suspicious rest pain. Especially diabetics, patients with known CAD or PAD
Board Question 3 A 75 yo male presents with typical claudication symptoms at 1 block, ABI 0.75 on the right, without rest pain or LE wounds. Segmental limb pressures suggest isolated SFA disease. Initial claudication therapy consists of A.) Formal supervised exercise therapy B.) Daily aspirin C.) Revascularization D.) A and B E.) A, B and C
Treatment: 1. RISK FACTOR MODIFICATION: a) Smoking Cessation b) Rigorous DM control c) BP reduction d) Lipid Lowering Therapy 2. EXERCISE: a) Claudication exercise rehabilitation program b) 45-60mins 3x weekly for 12 weeks c) 6 months later +6.5mins walking time (before pain) 3. MEDICAL MANAGEMENT: a) Antiplatelet therapy e.g. Aspirin/Clopidogrel b) Phosphodiesterase Inhibitor e.g. Cilostazol c) Foot Care
When to Image (CTA/MRA/Angiography): To image= To intervene Patients with disabling symptoms where revascularization is considered or CLI To accurately depict the anatomy of stenosis and plan for stent or surgery Occasionally when there is a discrepancy in history and clinical findings
Indications: Revascularization Claudication: Poor response to exercise rehabilitation + pharmacologic therapy. Significantly disabled by claudication, poor QOL The patient is able to benefit from an improvement in claudication Morphology of the lesion (low risk + high probabilty of operation success) CLI for wound healing, limb salvage, prior to amputation ALI
Revascularization Endovascular Angioplasty and Stenting Should be offered first to patients with significant comorbidities who are not expected to live more than 1-2 years Bypass Surgery Hybrid Procedure Amputation: Last Resort
Question A 54 you man was referred for evaluation because a abdominal CT done in the ED for a bout of gastroenteritis notes a 50% stenosis of the R iliac artery. He is active, frequently taking morning runs of 5-8 miles without any difficulties. According to PAD guidelines which of the following is a class I treatment recommendation for this lesion: A.) Endovascular intervention with a bare metal stent B.) Cilostazol C.) HMG CoA Reductase Inhibitor D.) Surgical evaluation for aorto iliac bypass grafting
Summary Treat PAD and CAD risk factors first and aggressively Make the diagnosis: ABI, non invasive studies Initiate supervised exercise therapy and possibly cilostazol for symptomatic claudication Refer to vascular specialist for abnormal ABI, symptoms of claudication and urgently for CLI, emergently for ALI.
Board Question Who is considered a vascular specialist: 1. Vascular Surgeon 2. Cardiologist 3. Interventional Cardiologist 4. Interventional Radiologist 5. All of the Above
Stacey Clegg MD Interventional Cardiology/Vascular Medicine University of New Mexico Hospital sclegg@salud.unm.edu Mark Sheldon MD Interventional Cardiology/Vascular Medicine University of New Mexico Hospital masheldon@salud.unm.edu VASCULAR MEDICINE INTERVENTIONAL CARDIOLOGY