Ankle Brachial Index

Health Care Comments Off
  • Normal ABI is ≥0.9 to as high as 1.3.
  • A normal test generally excludes arterial occlusive disease.
  • Mild disease and arterial entrapment syndromes can produce false negative tests.
  • If ABI is normal at rest but symptoms strongly suggest claudication, exercise testing should be done.
  • An ABI >1.3 suggests the presence of calcified vessels and the need for additional vascular studies, such as pulse volume recordings, measurement of the toe pressures and toe-brachial index, or arterial duplex studies.
  • An ABI ≤0.9 is diagnostic of occlusive arterial disease in patients with symptoms of claudication or other signs of ischemia and has 95% sensitivity (and 100% specificity) for detecting arteriogram-positive occlusive lesions associated with ≥50% stenosis in one or more major vessels.
  • An ABI of 0.4 to 0.9 suggests a degree of arterial obstruction often associated with claudication.
  • An ABI below 0.4 represents multilevel disease (any combination of iliac, femoral or tibial vessel disease), associated with non-healing ulcerations, ischemic rest pain or pedal gangrene.
  • A low ABI is associated with a higher risk of coronary heart disease, stroke, transient ischemic attack, progressive renal insufficiency, and all-cause mortality
  • Patients are exercised with the treadmill at a constant speed with no change in the incline of the treadmill over the course of the study – walking on the treadmill at 2 mph at a 12% incline for five minutes or until the patient is forced to stop due to pain (not due to SOB or angina). The walking distance, time to the onset of pain and nature of any symptoms are recorded. The ABI is recorded at rest, one minute after exercise, and every minute thereafter (up to 5 minutes) until it returns to the level of the resting ABI. The ABI in patients with severe disease may not return to baseline within the allotted time period.