Implantable Cardioverter-Defibrillators in Patients with CKD: A Propensity-Matched Mortality Analysis

Background and objectives Benefits of transvenous implantable cardioverter-defibrillators (ICDs) in prevention of sudden cardiac death among the general population are proven. However, the benefit of ICDs remains unclear in CKD. A propensity-matched analysis was conducted to examine the survival benefits of ICDs placed for primary prevention in those with CKD not on dialysis (eGFR<60 ml/min per 1.73 m(2)). Design, setting, participants, & measurements The Cleveland Clinic CKD registry was utilized to identify individuals who had an echocardiogram at the institution (between 2001 and October 2011). A propensity score of the likelihood of receiving an ICD was developed with the following variables: demographics, comorbid conditions, use of cardioprotective medications, eGFR, left ventricular ejection fraction, and ventricular arrhythmia. One-to-one greedy matching was used with 0.1 caliper width to match patients with and without an ICD. A Cox proportional hazards model was used to examine survival of matched patients with and without an ICD. Results This study included 1053 ICD patients and 9435 potential controls. Of 1053 ICD patients (60%), 631 were matched to the control group. During a median follow-up of 2.9 years (25th and 75th percentiles, 1.5, 4.7), 578 patients died. After adjusting for covariates, the hazard of mortality among propensity-matched patients was 0.69 (95% confidence interval [95% CI], 0.59 to 0.82) for the ICD group compared with the non-ICD group. A significant interaction was found between ICDs and eGFR (P=0.04). Presence of an ICD was associated with a lower risk of death among those with eGFRs of 45-59 ml/min per 1.73 m2 (hazard ratio [HR], 0.58; 95% CI, 0.44 to 0.77) and 30-44 ml/min per 1.73 m2 (HR, 0.65; 95% CI, 0.50 to 0.85), but not among those with eGFRs<30 ml/min per 1.73 m2 (HR, 0.98; 95% CI, 0.71 to 1.35). Conclusions Transvenous ICDs placed for primary prevention are associated with a survival benefit in those with stage 3 CKD, but not in those with stage 4 CKD.