Renal function and mortality following cardiac resynchronization therapy

Abstract

Cardiac resynchronization therapy (CRT) improves outcomes in heart failure, yet selection of patients likely to have survival benefit is problematic. Chronic kidney disease (CKD) is an important determinant of mortality in patients with congestive heart failure therefore we sought to determine the impact of CKD on mortality benefit after CRT. All CRT device implantations in patients not on dialysis at Mayo Clinic between January 1999 and December 2005 were included. Of 482 patients, 342 (71%) had CKD (defined as a glomerular filtration rate (GFR) of ≤60 mL/min/1.73 m(2)) at the time of device implantation. Patients with CKD were older (71 ± 10 vs. 63 ± 14 years, P < 0.01) than patients without CKD, and more often anaemic (12.70 ± 1.73 vs. 13.24 mg/L, P < 0.01), with similar ejection fraction (22 ± 8 vs. 23 ± 8%, P = 0.32). Survival was superior in patients with normal or mild renal dysfunction compared with patients with CKD (72 vs. 57% at 3 years, P < 0.01). After multivariate analysis, CKD remained a significant predictor of poor survival following CRT. Chronic kidney disease is common in patients undergoing CRT and associated with a higher mortality and should be considered when evaluating patients for CRT.