Validation of the relationship between ankle–brachial and toe–brachial indices and infragenicular arterial patency in critical limb ischemia

Abstract

The relationship between ankle-brachial index (ABI) remains uncertain relative to clinical and angiographic features of critical limb ischemia (CLI). From July 2011 to February 2013, 89 consecutive patients with CLI had non-invasive testing for indications of rest pain (n=23, 26%), as well as minor (n=29, 33%) and major (n=37, 42%) ischemic tissue loss. All patients subsequently underwent ABI testing and lower extremity angiography with visualization of the infragenicular arteries. Toe-brachial index (TBI) testing was available among 31 of these patients. Among patients with any ischemic tissue loss, 29% had an ABI between 0.7 and 1.4. Patients with rest pain alone had reduced odds of abnormal arterial runoff in univariate (OR 0.75, 95% CI 0.63-0.90; p=0.002) but not multivariate (p=0.50) analysis. Advanced age, increased ABI, reduced creatinine clearance, hyperlipidemia, and prior coronary artery disease were predictive of abnormal infragenicular runoff. Despite limitations in statistical power, median TBI, compared to ABI, tended to increase when infragenicular arterial runoff was preserved. Overall, the association of TBI with abnormal runoff was not significant (p=0.38). In conclusion, in the evaluation of CLI, nearly one-third of patients with any ischemic tissue loss had a normal or mildly reduced ABI. Assessment of TBI may augment the diagnostic accuracy of ABI in the evaluation of CLI.

Hospital Readmissions Following Endovascular Therapy for Critical Limb Ischemia: Associations With Wound Healing, Major Adverse Limb Events, and Mortality

“…Although reasons for this are unclear, rest pain is often caused by multilevel obstruction to arterial flow rather than discrete blockage (as is more commonly observed in patients with wounds) 19, 20. Furthermore, the occurrence of wound healing suggests response to therapy and adequate tissue perfusion, which may infer better outcomes than patients with persistent rest pain.…”

Treatment of lower limb ischaemia in patients with diabetes

“…A falsely elevated ABI may result from autonomic neuropathy and medial arterial calcinosis. Combination testing thus helps to improve diagnostic accuracy in this subgroup . Nonetheless, PAD is a less likely diagnosis in the presence of ABI 0.9 to 1.3, TBI ≥ 0.75 and triphasic pedal Doppler waveforms…”

Analysis of IN.PACT DEEP trial on the association between changes in perfusion from pre‐ to postrevascularization and clinical outcomes in critical limb ischemia

“…Furthermore, the recommended changes in ankle pressure, ABI, toe pressure, and TBI do not reflect an association with major adverse limb events (MALE) . Recent studies , including an analysis from the core laboratory‐adjudicated multicenter IN.PACT DEEP (randomized amphirion DEEP DEB vs standard PTA for the treatment of below the knee critical limb ischemia) trial, had showed that baseline TBI and toe pressure were markedly superior to ABI and ankle pressure in uncovering the presence of CLI by accurately reflecting the degree of hemodynamic impairment . Given the clinical and outcome differences among patients with claudication and CLI, especially in those with severe infragenicular disease, we sought to describe observed changes in ankle pressure, ABI, toe pressure, and TBI following revascularization and their association with MALE in this multicenter international core lab‐adjudicated clinical trial.…”