Ankle-Brachial Index for Peripheral Artery Disease Diagnosis

Rationale for ABI as Initial Test

The American Heart Association and American College of Cardiology recommend resting ABI for patients ≥65 years of age, or ≥50 years with risk factors including diabetes mellitus and hypertension 1, 2, 3
The American College of Cardiology suggests that patients with diabetes and hypertension are at high risk for PAD, even without symptoms, and ABI testing is appropriate for this population 1, 2
ABI results should be reported as abnormal (≤0.90), borderline (0.91-0.99), normal (1.00-1.40), or noncompressible (>1.40) 1, 2, 3

Approximately 21-23% of patients older than 55-65 years have PAD, with more than 40% being asymptomatic 4, 1
Patients with a family history of PAD have an increased risk for the disease 1, 2, 3

In diabetic patients, ABI may be falsely elevated (>1.40) due to arterial calcification, and toe-brachial index (TBI) measurement may be necessary 1, 2, 3
If ABI is abnormal (≤0.90), PAD is confirmed, and aggressive cardiovascular risk reduction should be initiated, including smoking cessation, statin therapy, antiplatelet agents, and blood pressure control 5, 6

Early detection of PAD is crucial as it classifies patients as "very high cardiovascular risk," requiring aggressive risk factor modification 5
Patients with PAD are at increased risk for cardiovascular death and all-cause mortality, making identification important even in asymptomatic individuals 4