Abstract 2433: Renal Insufficiency in Patients with Prophylactic ICD is Associated with Worse Survival but not Increased Risk of ICD Therapy
Background: Prophylactic ICD implantation in patients (Pts) with ejection fraction (EF) < 30% (MADIT II criteria) is associated with survival benefit due to prevention of sudden death. However, the impact of comorbid conditions such renal impairment (RI) on outcomes and frequency of ICD therapies is unknown.
Methods: We determined outcomes and frequency of ICD therapies in consecutive Pts undergoing ICD implantation for MADIT II indication at Mayo Clinic between 2000 and 2005 according the presence of RI (creatinine clearance (CrCl) by Modification of Diet in Renal Disease equation). RI was defined as CrCl < 60 ml/min/1.73m2. ICD therapies were defined as appropriate if triggered by sustained ventricular arrhythmias, and inappropriate if triggered by sinus tachycardia or atrial fibrillation.
Results: A total of 270 Pts were included. Of these, 163 (60%) had RI (mean MDRD 44.3 ± 10.6 ml/min/1.73m2 versus 77.1 ± 11.0 ml/min/1.73m2 in Pts without RI, p<0.01). Mean age of Pts with RI was 72 ± 9 years (140 male; 86%) versus 66 ± 11 years (107 male; 96%) in Pts without RI, p<0.01 for age and gender. Mean ejection fraction was similar (23% ± 6% vs. 23% ± 5%, p>0.05). Survival and frequency of appropriate ICD therapies is shown. RI was associaetd with worse survival (p<0.01) but not increased frequency of ICD therapies (p>0.05).
Conclusions: In Pts undergoing prophylactic ICD implantation for MADIT II criteria, RI is common and associated with significantly worse survival. However, frequency of ICD therapies is similar to that in Pts with normal renal function, suggesting that mortality benefit of ICD therapy in this population is limited.