Renal Response in Patients with Chronic Kidney Disease Predicts Outcome Following Cardiac Resynchronization Therapy

BACKGROUND: Chronic kidney disease (CKD) severity is associated with increased morbidity and mortality in congestive heart failure. There is a paucity of data regarding renal improvement after cardiac resynchronization therapy (CRT) and its potential impact on clinical outcomes, especially in patients with severe CKD. METHOD: This was a retrospective analysis of a prospectively collected cohort of 260 patients with CKD undergoing CRT at a single center. Renal function was compared before and after CRT. The primary end point was a composite of death, heart transplant, and left ventricular assist device (LVAD), assessed at 5 years. RESULTS: Patients with more severe CKD demonstrated increased risk of death, transplant, or LVAD following CRT (P = 0.015). Renal response (estimated glomerular filtration rate improvement ≥10 mL/min/1.73 m(2) ) was observed in 14% of all patients and 28% of patients with stage IV CKD. Independent predictors of renal response included left ventricular ejection fraction improvement (odds ratio [OR] 1.06, confidence interval [CI] 1.01-1.10), angiotensin-converting enzyme inhibitor/angiotensin receptor blocker use (OR 4.31, CI 1.08-17.23), and advanced CKD stage (OR 2.19, CI 1.14-4.23). Renal response independently decreased hazard of the primary outcome (HR 0.24, CI 0.08-0.73, P = 0.01). Renal responders with stage IV CKD had 80% 5-year event-free survival, compared to 0% for nonrenal responders in stage IV (P = 0.03). CONCLUSION: Although severity of CKD is associated with poorer outcome after CRT, improvement in renal function can occur in patients across all CKD stages. Renal responders, including those with stage IV CKD, demonstrate favorable 5-year outcomes. Assessment of renal response may help better prognostic outcomes following CRT.