The Effect of Chronic Kidney Disease on Mortality with Cardiac Resynchronization Therapy.

BACKGROUND: Cardiac resynchronization therapy (CRT) improves functional status, reduces heart failure hospitalizations, and decreases mortality. Several comorbidities including renal function affect outcomes with CRT. However, moderate to severe chronic kidney disease (CKD) was an exclusion criterion in the large randomized control trials.

OBJECTIVE: To evaluate the association of renal function on survival following CRT implantation.

METHODS: This was a retrospective analysis of 432 consecutive patients implanted with an implantable cardioverter defibrillator with CRT (CRT-D). The primary end point was defined as death by any cause, and it was determined using hospital records and the U.S. Social Security Death Index. A Kaplan-Meier analysis was performed separating renal dysfunction into renal stage based on glomerular filtration rate. Multivariate analysis was performed to assess the clinical predictors of mortality.

RESULTS: Patients were followed for up to 12 years with a mean follow-up time of 4.3 ± 3.2 years. A total of 164 patients (39.3%) died over the course of the study. Patients with normal and mild renal diseases (Stages 1 and 2) had improved survival compared with those with moderate-, severe-, or end-stage (Stages 3-5) renal disease. This effect remained statistically significant after multivariate analysis. The estimated 5-year mortality was 36.3% for stage 1, 33.4% for stage 2, 40.6% for stage 3, and 62.1% for stage 4/5 kidney disease (P = 0.004 by log-rank test).

CONCLUSION: CKD is a strong and an independent predictor of long-term mortality among patients undergoing CRT-D implantation.