Impact of critical limb ischemia on long-term cardiac mortality in diabetic patients undergoing percutaneous coronary revascularization

Abstract

Objective: Development of critical limb ischemia (CLI) has been reported as an independent predictor of cardiac mortality in diabetic patients. We aimed to determine whether CLI, managed in a structured setting of close collaboration between different vascular specialists and treated with early endovascular intervention, has any impact on long-term cardiac mortality of diabetic patients initially presenting with symptomatic coronary artery disease (CAD).

Research design and methods: We designed a prospective observational study of 764 consecutive diabetic patients undergoing percutaneous coronary intervention (PCI) in whom development of CLI was assessed by a dedicated diabetic foot clinic. Cardiac mortality at 4-year follow-up was the primary end point of the study.

Results: Among the 764 patients, 111 (14%) developed CLI (PCI-CLI group) and underwent revascularization of 145 limbs, with procedural success in 140 (96%). PCI-CLI patients at baseline had lower left ventricular ejection fraction (51 ± 11% vs. 53 ± 10%, P = 0.008), higher prevalence of dialysis (7% vs. 0.3%, P < 0.0001), and longer diabetes duration (13 ± 8 vs. 11 ± 7 years, P = 0.02) compared with PCI-only patients. At 4-year follow-up, cardiac mortality occurred in 10 (9%) PCI-CLI patients vs. 42 (6%) PCI-only patients (P = 0.2). Time-dependent Cox regression model for cardiac death revealed that CLI was not associated with an increased risk of cardiac mortality (hazard ratio 1.08 [95% CI 0.89-3.85]; P = 0.1).

Conclusions: The development of promptly assessed and aggressively treated CLI was not significantly associated with increased risk of long-term cardiac mortality in diabetic patients initially presenting with symptomatic CAD.

Trial registration: ClinicalTrials.gov NCT01676519.

Figure 1

Cox survival model for total mortality and cardiac mortality at 4-year follow-up in the overall study population.

Figure 2

Time-sensitive Cox proportional hazard regression model for independent predictors of cardiac death at 4-year follow-up in the overall study population. HR is reported with relative 95% CI. LVEF, left ventricular ejection fraction.