An Impaired Renal Function: A Predictor of Ventricular Arrhythmia and Mortality in Patients with Nonischemic Cardiomyopathy and Heart Failure

Background: This study investigated the overall mortality and the incidence of ventricular tachyarrhythmia (VT) in 99 patients with nonischemic cardiomyopathy (NICM) and with an implantable cardioverter defibrillator (ICD) suffering from heart failure. Methods: We performed a stepwise regression model to identify independent risk factors for the occurrence of ventricular arrhythmias. Using a Cox regression model, independent risk factors for total mortality were evaluated and, subsequently, a Kaplan-Meier analysis was applied. The primary endpoint of this study was the identification of independent predictors of overall mortality and the incidence of malignant arrhythmias. Results: One hundred twenty-five VT (>= 310 ms), 51 fast VT (between 310 ms and 240 ms), and 48 episodes of ventricular fibrillation (<= 240 ms) were documented in 32 patients. Independent predictors of arrhythmias detected and treated by the ICD included female gender (odds ratio [OR] 3.4), lack of statin therapy (OR 3.5), and increased serum creatinine (OR 3.7). The Kaplan-Meier analysis showed no difference in survival between participants with or without VT. Total mortality was predicted by increased age (OR 2.3) and an impaired renal function (OR 1.9), independently. Conclusions: In this cohort of NICM patients with heart failure, female gender, lack of statin therapy, and increased creatinine represented independent risk factors for the incidence of malignant arrhythmias. Furthermore, renal insufficiency and age favored total mortality. Considering these results, impaired renal function might represent a valuable noninvasive tool to identify NICM patients who, despite ICD implantation, have the highest risk of mortality and therefore require a particularly thorough follow-up. (PACE 2011; 34: 894-899)