Helpful in diagnosis of peripheral arterial disease
Also, decreased ABI associated with high-risk CAD, stroke, TIA, renal insufficiency and all-cause mortality.
Normal: 0.9 – 1.3
> 1.3 = calcified, sclerotic vessels
< 0.9 if occlusive arterial disease (95% sens, 100% spec)
< 0.4 suggestive of multilevel disease (iliac, femoral, tibial) and associated with non-healing ulcers and gangrene
For diabetics, a toe-brachial index is preferred because of sparing from calcification
- TBI 0.7-0.8 is normal range.