280.1 🎓 醫孞生版

280.1.0.1 📌 䞀頁重點

280.1.0.1.1 Definition + Epidemiology
280.1.0.1.1.1 PAD
  • Atherosclerotic disease of non-coronary arteries (lower extremity > upper)
  • Affects ~ 200 million worldwide; 12% of adults ≥ 60
  • Increasing in elderly + DM
  • Often co-exists with CAD + cerebrovascular disease (polyvascular disease)
  • 5-year all-cause mortality 25% (worse than many cancers)
280.1.0.1.1.2 Risk Factors
  • Smoking (#1, dose-dependent, 5-10x risk)
  • Diabetes (4x risk, plus accelerated progression)
  • Hypertension
  • Dyslipidemia
  • Age (esp > 65)
  • CKD
  • Hyperhomocysteinemia
280.1.0.1.2 Classification
280.1.0.1.2.1 Anatomic
  • Aorto-iliac (inflow): from aorta to common iliac
  • Femoro-popliteal: from femoral to popliteal (most common)
  • Tibial / infrapopliteal: tibial / peroneal vessels (esp in DM)
280.1.0.1.2.2 Severity (Fontaine + Rutherford)

Fontaine Classification: | Stage | Symptoms | |——-|———-| | I | Asymptomatic | | IIa | Mild claudication (> 200 m) | | IIb | Moderate-severe claudication (< 200 m) | | III | Rest pain | | IV | Ulcer / gangrene |

Rutherford Classification (more detailed): - 0: Asymptomatic - 1-3: Claudication (mild/moderate/severe) - 4: Rest pain - 5: Minor tissue loss - 6: Major tissue loss

280.1.0.1.2.3 WIfI (2014 — for CLTI)
  • Wound (0-3)
  • Ischemia (0-3)
  • fInfection (0-3)
  • Risk-stratifies amputation risk and benefit of revascularization
280.1.0.1.3 Clinical Presentation
280.1.0.1.3.1 Intermittent Claudication
  • Reproducible, exertion-induced muscle pain
  • Calf > thigh > buttock
  • Relieved by 2-10 min rest
  • “Vascular claudication”
  • Different from “neurogenic claudication” (spinal stenosis):
    • Neurogenic worsens with standing, improves with flexion
    • Vascular relieved purely by rest
280.1.0.1.3.2 Rest Pain
  • Pain at rest, esp at night
  • Hangs leg over edge of bed for relief
  • Severe disease
280.1.0.1.3.3 Chronic Limb-Threatening Ischemia (CLTI)
  • Replaces “critical limb ischemia”
  • Rest pain ≥ 2 weeks + ulcer / gangrene + objective ischemia (ABI < 0.40 or TBI < 30)
  • Limb amputation risk ↑
  • 1-year mortality ~ 25%
  • Emergency revascularization
280.1.0.1.3.4 Acute Limb Ischemia (ALI)
  • Sudden ↓ flow → “6 Ps”:
    • Pain
    • Pallor
    • Pulselessness
    • Paresthesias
    • Paralysis
    • Poikilothermia (cold)
  • Etiology: embolism (AF), thrombosis (acute on chronic), trauma, dissection
  • EMERGENCY: heparin + revascularization (lysis, thrombectomy, surgery) within 6 hours
280.1.0.1.4 Physical Examination
  • Pulse exam: femoral, popliteal, dorsalis pedis, posterior tibial
  • Auscultation: bruits over femoral, abdominal aorta
  • Skin:
    • Hair loss
    • Cool, pale, shiny skin
    • Atrophy
    • Ulcers (location, characteristics)
    • Gangrene
  • Capillary refill: > 4 sec abnormal
  • Buerger’s test: pallor on elevation, rubor on dependency
280.1.0.1.5 Diagnosis
280.1.0.1.5.1 Ankle-Brachial Index (ABI)
  • Highest ankle systolic / Highest brachial systolic
  • ABI ≀ 0.90 = PAD
  • 0.91-1.00 = borderline
  • 1.01-1.40 = normal

  • 1.40 = non-compressible (calcified, DM/CKD) → use TBI

  • < 0.50 = severe
  • < 0.40 = CLTI threshold
280.1.0.1.5.2 Toe-Brachial Index (TBI)
  • For non-compressible vessels (DM, CKD)
  • TBI < 0.70 = abnormal
  • TBI < 0.30 = CLTI
280.1.0.1.5.3 Exercise ABI
  • For symptomatic patients with normal resting ABI
  • Confirms claudication
280.1.0.1.5.4 Pulse Volume Recording (PVR)
  • Segmental waveforms localize disease
280.1.0.1.5.5 Duplex Ultrasound
  • Identifies stenosis location, severity
  • Visualizes plaque
  • Useful for follow-up
280.1.0.1.5.6 CT Angiography (CTA)
  • First-line for anatomy if intervention planned
  • Calcification can be problematic in DM/CKD
280.1.0.1.5.7 MR Angiography (MRA)
  • Alternative to CTA
  • Gadolinium concerns in CKD
280.1.0.1.5.8 Catheter Angiography
  • Gold standard
  • During endovascular intervention
280.1.0.1.6 Management
280.1.0.1.6.1 Risk Factor Modification (Foundation)
  • Smoking cessation (most important; reduces MACE 30%+)
  • DM: HbA1c < 7% (individualized); SGLT2i / GLP-1 RA for CV protection
  • BP: < 130/80; ACEi/ARB first-line (HOPE trial)
  • Lipid: high-intensity statin → LDL < 55 mg/dL (very high risk)
  • Lifestyle: Mediterranean diet, weight loss
280.1.0.1.6.2 Antiplatelet Therapy
  • ASA 81-100 mg daily OR
  • Clopidogrel 75 mg daily (CAPRIE — slightly better than ASA)
  • Don’t combine ASA + clopidogrel routinely (CHARISMA — no benefit)
280.1.0.1.6.3 Antithrombotic Combination
  • COMPASS (2017): rivaroxaban 2.5 mg BID + ASA vs ASA alone
    • ↓ MACE 24%, ↓ MALE 46%
    • ↑ bleeding 70%
  • VOYAGER PAD (2020): rivaroxaban 2.5 mg BID + ASA post-PCI/surgery
    • ↓ MALE, ↓ MACE
    • Class IIa for symptomatic PAD post-revascularization
280.1.0.1.6.4 Statin Therapy
  • High-intensity statin (atorvastatin 80 mg or rosuvastatin 20-40 mg)
  • LDL target < 55 mg/dL
  • Adjunct: ezetimibe, PCSK9 inhibitor, bempedoic acid
280.1.0.1.6.5 Supervised Exercise Therapy (SET)
  • Class I recommendation for claudication
  • 12-week program, 3x/week, 30-45 min walking near maximal pain
  • Improves walking distance more than meds
  • Mechanisms: collaterals, mitochondrial function, endothelial improvement, gait efficiency
  • HBET (home-based) — alternative if SET unavailable
280.1.0.1.6.6 Pharmacotherapy for Claudication
  • Cilostazol 100 mg BID
    • Phosphodiesterase III inhibitor
    • ↑ walking distance 40-60%
    • Contraindicated in HFrEF (↑ mortality)
  • Pentoxifylline — older, less effective
  • Statin — itself improves walking distance
280.1.0.1.6.7 Revascularization
  • Indications:
    • Lifestyle-limiting claudication despite OMT + exercise + 3 months
    • CLTI (rest pain, ulcer, gangrene)
    • Acute limb ischemia
280.1.0.1.6.8 Endovascular (PTA + stenting)
  • First-line for short segment, focal lesions, aorto-iliac
  • DCB (drug-coated balloon) — better patency for SFA
  • DES (drug-eluting stent) — for some
  • Atherectomy for calcified
  • Distal extremity smaller vessels — angioplasty
280.1.0.1.6.9 Surgical Bypass
  • Aorto-bifemoral for aorto-iliac
  • Femoral-popliteal / femoral-tibial for distal
  • Single-segment greater saphenous vein (GSV) best conduit
  • Prosthetic graft (PTFE) if no vein available
  • BEST-CLI 2022 — see below
280.1.0.1.6.10 Endovascular vs Surgical (BEST-CLI 2022)
  • N = 1830 CLTI patients
  • Cohort 1: single-segment GSV available
    • Bypass surgery → ↓ MALE compared to endo
  • Cohort 2: GSV not available
    • Bypass = endo
  • Implications:
    • GSV available + young + fit: surgery
    • No GSV / old / unfit: endo
    • Combined approach (endo first, surgery if fails) reasonable
280.1.0.1.6.11 Wound Care + Amputation
  • Multidisciplinary team (vascular, wound, ID, PT, prosthetist)
  • Off-loading, debridement, antibiotics, hyperbaric O₂ (selected)
  • Major amputation: BKA > AKA when possible (better function)
280.1.0.1.7 Acute Limb Ischemia (ALI)
280.1.0.1.7.1 Rutherford ALI Classification
  • I: Viable; not threatened immediately (no sensory loss, no muscle weakness)
  • IIA: Marginally threatened; salvage with prompt Rx
  • IIB: Immediately threatened; salvage with immediate Rx
  • III: Irreversible; major tissue loss / amputation regardless
280.1.0.1.7.2 Management
  • Heparin bolus 80 U/kg + infusion ASAP
  • Class I + IIA: catheter-directed thrombolysis (CDT) or thromboembolectomy
  • IIB: surgical thromboembolectomy or hybrid
  • III: amputation
  • Hemodynamic resuscitation
  • Investigate source (echo, telemetry for AF)
280.1.0.1.8 Differential — Non-Atherosclerotic PAD
  • Thromboangiitis obliterans (Buerger’s): young smokers, distal vessels
  • Vasculitis (Takayasu, GCA, polyarteritis)
  • Fibromuscular dysplasia: young women, “string of beads”
  • Popliteal entrapment syndrome: anatomic compression
  • Adventitial cystic disease
  • Radiation-induced
  • Cocaine-related

280.1.0.2 🩺 床邊速查

  • ABI ≀ 0.90 = PAD (≀ 0.40 = CLTI; > 1.40 = non-compressible)
  • Claudication: calf > thigh, reproducible, relieved by rest 2-10 min
  • CLTI = rest pain ≥ 2 wk or ulcer/gangrene; 1-yr mortality 25%
  • ALI 6 Ps: pain, pallor, pulselessness, paresthesias, paralysis, poikilothermia
  • Treatment: smoking cessation + supervised exercise + ASA/clopidogrel + statin + cilostazol; rivaroxaban 2.5 mg BID + ASA (COMPASS, VOYAGER)
  • CLTI revasc: BEST-CLI 2022 — surgery if GSV available, endo otherwise