Abstract 5700: Worsening Renal Function and Arrhythmic Event in Implantable Cardioverter Defibrillator Patients with Nonischemic Heart Failure
Purpose: Implantable Cardioverter Defibrillator (ICD) prevents sudden cardiac death in high risk patients with heart failure (HF). Worsening renal function (WRF) is associated with mortality in patients with myocardial infarction or HF, but its effect on lethal arrhythmia is unknown. We evaluated the influence of WRF on the occurrence of arrhythmic events in patients with nonischemic HF and ICD.
Methods: A total of 286 nonischemic HF patients who underwent ICD implantation between 1990 and 2007 were studied. Estimated Glomerular Filtration Rate (eGFR) was calculated using the Modification of Diet in Renal Disease. Renal dysfunction was defined as eGFR <60mL/min/1.73m2 and WRF was defined as 15mL/min/1.73m2 per year. Differences in arrhythmia recurrences according to the eGFR and WRF were compared by Kaplan-Meier survival curves.
Results: During a mean follow-up time of 2.2+/−1.0 years, 94 (33%) of 286 patients (mean age; 57+/−15 years, 72% male) experienced appropriate ICD shock therapy. There was a significantly higher cumulative rate of appropriate ICD shock therapy (p<0.05) and electrical storm (p<0.05) in patients with renal dysfunction than others. The patients with renal dysfunction at baseline experience WRF more frequently than other patients (53% vs. 23%, respectively, p<0.01). After correcting for age, sex, left ventricular ejection fraction (LVEF), indication for ICD implantation, and use of beta-blockers in a Cox regression model, WRF was still an independent predictor of the time to first appropriate shock (HR 2.21, 95% CI 1.32–3.69, p<0.05) and electrical storm (HR 2.22, 95% CI 1.19 – 4.13, p<0.05). The result of subgroup analysis of 147 patients with low LVEF (LVEF<35%) indicated that the patients with WRF experienced electrical storms more frequently (p<0.05).
Conclusion: WRF is associated with increased rate of arrhythmic event in nonischemic HF patients. Especially, those patients with low LVEF and WRF experience more frequent ICD shocks.