Non-compressible ABIs are associated with an increased risk of major amputation and major adverse cardiovascular events in patients with critical limb ischemia

Abstract

Ankle-brachial indices (ABIs) are important for the assessment of disease burden among patients with peripheral artery disease. Although low values have been associated with adverse clinical outcomes, the association between non-compressible ABI (ncABI) and clinical outcome has not been evaluated among patients with critical limb ischemia (CLI). The present study sought to compare the clinical characteristics, angiographic findings and clinical outcomes of those with compressible (cABI) and ncABI among patients with CLI. Consecutive patients undergoing endovascular evaluation for CLI between 2006 and 2013 were included in a single center cohort. Major adverse cardiovascular events (MACE) were then compared between the two groups. Among 284 patients with CLI, 68 (24%) had ncABIs. These patients were more likely to have coronary artery disease ( p=0.003), diabetes ( p<0.001), end-stage renal disease ( p<0.001) and tissue loss ( p=0.01) when compared to patients with cABI. Rates of infrapopliteal disease were similar between the two groups ( p=0.10), though patients with ncABI had lower rates of iliac ( p=0.004) or femoropopliteal stenosis ( p=0.003). Infrapopliteal vessels had smaller diameters ( p=0.01) with longer lesions ( p=0.05) among patients with ncABIs. After 3 years of follow-up, ncABIs were associated with increased rates of mortality (HR 1.75, 95% CI: 1.12-2.78), MACE (HR 2.04, 95% CI: 1.35-3.03) and major amputation (HR 1.96, 95% CI: 1.11-3.45) when compared to patients with cABIs. In conclusion, ncABIs are associated with higher rates of mortality and adverse events among those undergoing endovascular therapy for CLI.

Association of Ankle-Brachial Indices With Limb Revascularization or Amputation in Patients With Peripheral Artery Disease

“…In prior studies, for the subset of patients with PCA and CLI, there was angiographic evidence of extensive disease with long lesions and small vessel diameters. 40 , 41 Accordingly, our hypothesis is that the mechanism for increased risk for amputation in patients with PCA was likely due to presence of a combination of the following factors: underrecognition of CLI, extensive atherosclerotic disease with long lesions, and small vessel diameter more likely to occur in patients with diabetes and chronic kidney disease.…”

“…Prior studies have shown that patients with PCA were more likely to have diabetes, to have chronic kidney disease, and to undergo limb amputation. 40 , 41 Weinberg et al 42 have shown by angiography that patients with PCA have high rates of PAD with predilection for the infrapopliteal arteries. In prior studies, for the subset of patients with PCA and CLI, there was angiographic evidence of extensive disease with long lesions and small vessel diameters.…”

Comparison of different methods of ABI acquisition for detection of peripheral artery disease in diabetic patients

“…Therefore, these patients should be considered as likely to have PAD and always sent for further examination (bear in mind that we are discussing a screening test now, not a diagnostic test). Such a decision is also supported by the conclusions of Aboyans 7 and others 8,9 that high ABI bears a significant risk of development of serious complications and should be considered as PADequivalent 7 .…”

“…ABI values of 0.91 to 0.99 are considered "borderline" while values over 1.40 indicate non-compressible arteries [4][5][6] associated with vascular calcifications, potentially bearing an even more serious effect on the quality of life than low ABI (ref. [7][8][9] ). The guidelines recommend use of the higher SBP from the two arteries at the ankle level for ABI calculation.…”

Perfusion Assessment in Critical Limb Ischemia: Principles for Understanding and the Development of Evidence and Evaluation of Devices: A Scientific Statement From the American Heart Association

“…Finally, among 284 patients with CLI, the presence of noncompressible vessels was associated with a greater likelihood of amputation (hazard ratio, 1.75 [95% CI, 1.12-2.78]) and major adverse cardiovascular events (hazard ratio, 2.04 [95% CI, 1.35-3.03]) over 3 years of follow-up than in those with CLI and compressible vessels. 20 It is noteworthy that the ABI may be partially compressible, with resultant values that underestimate the severity of disease; in a series of 5984 patients with CLI who were undergoing revascularization in a large statewide registry, 21% had normal ABI and 53% had only mildly reduced ABI. 13 Infrapopliteal PAD is present among a large proportion of patients presenting with CLI.…”