Clinical Outcomes in Patients with Severe Renal Dysfunction Including Dialysis Following Defibrillator Implantation

Background: Renal dysfunction is associated with increased mortality in heart failure (HF) patients. However, there are limited data regarding clinical and arrhythmic outcomes associated with implantable cardioverter defibrillator (ICD) therapy in this population. Methods: We evaluated outcomes associated with the severity of renal dysfunction with or without dialysis among 2,289 patients who were enrolled and prospectively followed up in the Israeli ICD Registry. The primary endpoint of the study was all-cause mortality. Secondary endpoints included cardiac mortality, HF hospitalization, non-cardiac hospitalization, and appropriate and inappropriate ICD therapy. Results: Severe renal dysfunction patients (estimated glomerular filtration rate <30 ml/min/1.73 m²; n = 144 patients; 6%) were older, with higher comorbidities prevalence, and more likely to suffer from advanced HF. Among severe renal dysfunction patients, those on dialysis had a lower prevalence of wide QRS and complete left bundle branch morphology, resulting in lower cardiac resynchronization therapy defibrillator (CRTD) implantation rates. Dialysis was associated with an overall increased risk for all-cause mortality (hazard ratio (HR) 3.22; 95% CI 1.69-6.13; p < 0.01) and for noncardiac hospitalizations (HR 2.80; p < 0.001) compared to all other study patients. However, within the subgroup of patients with severe renal dysfunction, the presence of dialysis was not an independent risk factor for all-cause mortality (HR 0.99; p = 0.97) as compared to non-dialysis. The rate of appropriate ICD therapy for ventricular tachyarrhythmias increased with declining renal function, with the highest rate observed among those undergoing dialysis. Conclusions: The present findings suggest that dialysis does not significantly modify the adverse outcomes associated with severe renal dysfunction following ICD/CRTD implantation.