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

Abstract

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). 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. 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). 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.