Toe- Brachial Index: Utility, Futility, and Diagnostic Criteria

Authors:
Publisher website
Google Scholar
Abstract
Ankle brachial index (ABI) can be unreliable in patients with non-compressible vessels. Our aim is to determine the feasibility of toe brachial index (TBI) and reporting criteria in a large population. We evaluated Doppler waveforms and segmental pressures in 26,719 limbs. TBI was obtained in 92.7%, mean TBI = 0.61 ± 0.25. TBI was obtained in 82%of limbs with unobtainable ABI. In hemodynamically normal subgroup (defined as those with normal ankle-brachial indices at rest and after exercise) the mean TBI was 0.84 ± 0.14. In severe PAD subgroup (defined as ABI < 0.5 and monophasic waveforms) the mean TBI was 0.16 ± 0.12. Limbs with a diagnosis of a PAD (ABI ≤ 0.9) had a TBI <0.8 in 99.5% of the cases, and <0.6 in 90% of the cases. A TBI of 0.8 had a negative predictive value for PAD of 0.99. A TBI cutoff of 0.6 had a positive predictive value for PAD of 0.95. Based on these results we propose defining normal TBI above 0.8, borderline between 0.8 and 0.61, abnormal TBI ≤ 0.6 and severe PAD as TBI ≤ 0.2. In conclusion TBI can be reliably measured in patients with PAD and offer valuable information when diagnosing PAD. We present our diagnostic criteria based on clinical data.

This publication has 23 references indexed in Scilit: