Peripheral Arterial Disease. Westley Smith MD Vascular Fellow

Transcription

1 Peripheral Arterial Disease Westley Smith MD Vascular Fellow

2 Background (per 10,000) Goodney P, et al. Regional intensity of vascular care and lower extremity amputation rates. JVS. 2013; 6:

3 Background Goodney, P. et al. Variation in the Use of Lower Extremity Vascular Procedures for Critical Limb Ischemia. Circulation. 2012;5:94-102

4 Background Approximately 2 million living amputees Primary cause being PVD Nearly 200,000 new amputations every year Amputation associated hospital costs 2009 were $8.3 billion dollars

5 Classification Claudication Rest Pain Tissue Loss

6 Classification Claudication Most commonly calf pain ranging from fatigue to aching while walking Less commonly thigh or buttock pain with or without impotence (Leriche s) From ischemic neuropathy involving unmyelinated sensory fibers and anaerobic muscular acidosis Reproducible Alleviated by rest

7 Classification Claudication Disease Location Single level most common from iliac or SFA (MC) Inflow disease: Aorto-iliac disease (supra-inguinal) Outflow disease: femoral to pedal vessels (infra-inguinal) Multi-level disease less common

8 Classification Critical Limb Ischemia Rest pain Burning sensation, uncomfortable coldness, paresthesia improved with dependent positioning of forefoot Associated with high risk of limb loss without revascularization Tissue loss usually result of repetitive tissue trauma, mild though it may be in the setting of inadequate perfusion to allow healing Ischemic Gangrene occurs with resting limb blood flow is insufficient to maintain cellular viability

9 Classification Critical Limb Ischemia Usually requires presence of two or more levels of disease Most commonly two sequential vascular beds i.e. femoral-popliteal & tibial Less commonly parallel vascular beds i.e. SFA & PFA

10 Epidemiology Natural History of Disease Edinburgh Arterial Study: Age matched patients to those with normal ABI > 0.9 had increased risk of mortality. Further augmentation of lifestyle to alleviate symptoms demonstrated a worsened prognostic factor. McDermott found women me be more likely to alleviated symptoms with lifestyle changes and ultimately more rapid decline and poorer prognosis Cardiovascular Health Study (1993): 4705 participants with depressed ABI s found to have an increased risk mortality from MI and stroke as MET s achieved decreased

11 Epidemiology Prevalence Based on Risk Factors Norgen et al: TASC II Working-Group, Inter-Society Concensus for Management of Peripheral Vascular Disease. JVS 45; S9A, 2007

12 Epidemiology Impact of Claudication on Extremity: only 1 of 4 claudicants will progress to Critical Limb Ischemia. At risk factors included insulin dependent DM, and failure to stop smoking. Overall risk of progression to amputation ~5% over a 5 year period Impact of Critical Limb Ischemia 40% Limb loss 20% mortality 6 months from onset Norgen et al: TASC II Working-Group, Inter-Society Concensus for Management of Peripheral Vascular Disease. JVS 45; S9A, 2007

13 Diagnosis History & Physical Exam Differentiate vascular etiologies and non-vascular / neurogenic etiologies Focused pulse exam Risk Factors Age, HTN, DM, CKD, HLD, Smoking Atypical presentation consider atypical risk factors Hypercoagulable disorders, Aneurysms, Embolic sources,popliteal Entrapment

14 Diagnosis Initial Hematologic Studies Characterize risk factors and identify end organ damage (MC creatinine) CBC, glucose, A1c, Creatinine, HLD Hypercoagulable Disorders Coagulation Panel, Protein C & S, Factor V, AT III, Anticardiolipin, fibrinogen, Lupus assay, homocysteine Vascular Lab Studies

15 Diagnosis Vascular Laboratory and Imaging Ankle Brachial Index and Segmental Pressures with toes pressures Pulse Volume Recording ABI Severity normal abnormal.6-.9 mild.4-.6 moderate.<.4 severe

16 Diagnosis Duplex imaging B Mode Velocities and Waveforms Gerhard-Herman M, et al. Guidelines for Noninvasive Vascular Laboratory Testing: A Report from the American Society of Echocardiography and the Society of Vascular Medicine and Biology. Journal American Society of Echocardiography;19:

17 Diagnosis MRI/MRA Aorto-iliac and femoral-popliteal disease MRA is equal to Digital Subtraction Angiography Infrapopliteal disease Non-contrast MRI superior to MRA because of venous artifact, but DSA superior to non-contrast MRI

18 Diagnosis CTA Timing bolus dependent Generally good Aorto-iliac imaging More limited tibial imaging Artifacts secondary to Calcified vessels

19 Diagnosis Angiography The Gold Standard

20 Diagnosis Modality Advantages Disadvantages ABI Quick, no radiation, easily repeated Multilevel disease difficult, poorly localizing, unreliable in calcified vessels Duplex MRI Some retroperitoneal capabilities, quick, some role for specific delineation Improved RP capabilities, no radiation, contrast and noncontrast capabilities Technically dependent, multilevel disease challenging multilevel disease may be difficult, in stent restenosis limited, expensive, timely CTA Quick, readily accessible Image quality and artifact limiting, radiation exposure DSA Treatability Radiation, invasive, expensive

21 Non-Invasive Treatment Considerations of both disease process/symptoms and functionality/health of patient must be considered when deciding on medical management vs revascularization Smoking Cessation Improved by physician assistance at 5 years from 5% to 22% Buproprion, Varenicline Diabetes Management Each 1% increase in HbA1c may increase risk of PVD by 28% 2016 American Diabetic Association recommends HbA1c level 6.5 HTN Current BP recommendations 140/90 in high risk groups including PAD Tighter management of 130/80 in DM and CKD patients ACE inhibitors may provide some cardiovascular protectiveness, but overall BP reduction seems most beneficial

22 Non-invasive Treatment High Cholesterol levels >200mg/dL, low HDL levels <40, and high LDL levels >130 have demonstrated increased cardiovascular risk Stabilize existing plaques Minimize oxidative stress Reduce vascular inflammation PAD disease benefits of statins have been limited to sub-group analyses with view independently designed PAD studies American Heart Association recommends LDL<100 in PAD patients and <70 in patients with well known more systemic atherosclerosis Hyperhomocysteinemia Promotes endothelial dysfunction and platelet aggregation Supplementation with B vitamins and folate However failure of high dose folate therapy proof to be cardio protective

23 Non-invasive Treatment Antiplatelet Therapy Antiplatelet Trialist Collaboration: demonstrated fatal and non-fatal absolute reduction of 2.5% benefit for those on anti-platelet therapy CAPRIE trial: ASA vs Plavix demonstrated benefit in secondary prevention in patients with known cardiovascular those taking Plavix over ASA with concomitant PAD (relative risk reduction 24%) Other Antiplatelet medications with ongoing studies some not yet available in US

24 Non-invasive Treatment Exercise Therapy for Claudication

25 Non-Invasive Treatment Medications Specific for Claudication Several not available in US Or no longer approved

26 Non-Invasive Treatment Medications Specific for Claudication

27 The old and the new