Renal dysfunction predicts long-term mortality in patients with lower extremity arterial disease.

BACKGROUND: Patients with renal insufficiency tend to suffer from advanced atherosclerosis and exhibit a reduced life expectancy. OBJECTIVES AND DESIGN: This prospective study investigated the relation between renal dysfunction and long-term all-cause and cardiovascular mortality in a population of nonsurgical patients with lower extremity arterial disease (LEAD). SUBJECTS AND METHODS: A total of 357 patients with symptomatic LEAD underwent baseline glomerular filtration rate (GFR) estimation by the 4-variable Modification Diet in Renal Diseases equation, and were then followed for 4.2 years (range: 1-17). RESULTS: During follow-up, 131 patients died (8.6 deaths per 100 patient-years), 79 of whom (60%) from cardiovascular causes. All-cause death rates were 3.8, 6.6, and 15.5 per 100 patient-years, respectively, in the groups with normal GFR, mild reduction in GFR (60-89 mL min(-1) per 1.73 m2) and chronic kidney disease (CKD; <60 mL min(-1) per 1.73 m2; P < 0.001 by log-rank test). Compared to patients with normal renal function, the risk of all-cause and cardiovascular death was significantly higher in patients with CKD [hazard ratio, respectively, 2.23, 95% confidence interval (CI): 1.16-4.34, P = 0.017; 2.15, 95% CI: 1.05-4.43, P = 0.03]. The association of CKD with all-cause and cardiovascular mortality were independent of age, LEAD severity, cardiovascular risk factors and treatment with angiotensin-converting enzyme (ACE)-inhibitors, hypolipidaemic and antiplatelet drugs. The power of GFR in predicting all-cause death was higher than that of ankle-brachial pressure index (P = 0.029) and Framingham risk score (P < 0.0001). CONCLUSION: Chronic kidney disease strongly predicts long-term mortality in patients with symptomatic LEAD irrespective of disease severity, cardiovascular risk factors and concomitant treatments.