Poor prognosis for patients with chronic kidney disease despite ICD therapy for the primary prevention of sudden death

Introduction: Chronic kidney disease (CKD) has been independently associated with increased cardiovascular mortality. Little is known about the benefit of implantable cardioverter defibrillator (ICD) therapy for prevention of sudden death in this large, high-risk population. We sought to evaluate the impact of CKD on survival in patients who received an ICD for primary prevention of sudden death. Methods and Results: In this retrospective study of patients who underwent ICD implantation for primary prevention of sudden death, patients were stratified by CKD, defined as serum creatinine >= 2 mg/dL or dialysis use. Primary endpoint was mortality. CKD was identified in 35 of 229 patients (15.3%). There were 33 deaths during a follow-up period of 18.0 +/- 15.2 months: 17 of 35 CKD patients and 16 of 194 patients without CKD (48.6% vs 8.2%, P < 0.00001 by log-rank). One-year survival for patients with and without CKD was 61.2% and 96.3%, respectively. Cox regression analysis controlling for age, sex, comorbidities, ejection fraction, and medications proved CKD to be the strongest independent predictor of death (hazard ratio 10.5; 95% confidence interval 4.8-23.1; P = 0.0001). This risk was dependant on severity of CKD; a 10 mL/min reduction in creatinine clearance was associated with a 55% increase in hazard of death (P < 0.0001). Conclusions: In patients receiving an ICD for primary prevention of sudden death, CKD significantly reduced long-term survival. This poor prognosis may limit the impact of primary prevention ICD therapy in this patient population.