Prognostic value of renal function in patients with cardiac resynchronization therapy

Background Renal insufficiency is prevalent in patients with heart failure and indicates poor prognosis. We examine (i) the relationship between left ventricular (LV) reverse remodeling (RR) and renal function and (ii) the prognostic value of renal function in patients receiving cardiac resynchronization therapy (CRT). Methods The relationship between LV-RR, defined as a 10% reduction in LV end-systolic volume, and renal function was examined in 85 consecutive patients receiving CRT. Echocardiographic assessment and renal function tests were performed before and 3 months after CRT. All-cause mortality and the composite of mortality or heart failure hospitalization between those with preserved or deteriorated renal function at 3 months were assessed by Kaplan Meier analysis. Results There was a slight improvement in glomerular filtration rate (GFR) in those with LV-RR (n = 44; 51.7 ± 20.4 vs. 54.2 ± 19.1 ml/min/1.73m2; p = 0.024) while a significant deterioration (n = 41; 61.9 ± 17 vs. 48.8 ± 13.0 ml/min/1.73m2; p < 0.001) was observed in those without LV-RR. The change (Δ) in GFR was significantly correlated with ΔLV end-systolic/diastolic volumes and ΔLV ejection fraction. After follow up of 856.4 ± 576.8 days, patients with preserved renal function had significant lower all-cause mortality (log rank χ2 = 4.82, p = 0.029) and the composite endpoints (log rank χ2 = 5.04, p = 0.025). Conclusion Preservation of renal function was observed in patients with systolic heart failure and renal insufficiency responding to CRT and provided prognostic information. A rapid decline in renal function after CRT was associated with worse clinical outcomes.