BACKGROUND Prior studies have reported that more than 20% of implantable cardioverter-defibrillator (ICD) implantations in the United States do not adhere to trial-based criteria. OBJECTIVE We sought to investigate the patient characteristics associated with not meeting the inclusion criteria of the clinical trials that have demonstrated the efficacy of primary prevention ICDs. METHODS Using data from the National Cardiovascular Data Registry's ICD Registry, we identified patients who received ICDs for primary prevention from January 2006 to December 2008. We determined whether patients met the inclusion criteria of at Least 1 of the 4 ICD primary prevention trials: Multicenter Automatic Defibrillator Implantation Trial (MADIT), MADIT-II, Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT), and the Multicenter Unsustained Tachycardia Trial (MUSTT). RESULTS Among 150,264 patients, 86% met criteria for an ICD implantation based on trial data. The proportion of patients who did not meet trial-based criteria increased as age decreased. In multivariate analysis, the significant predictors for not meeting trial criteria included prior cardiac transplantation (odds ratio [OR] 2.1), pediatric electrophysiology operator (OR 2.0), and high-grade atrioventricular conduction disease (OR 1.4). CONCLUSION Among National Cardiovascular Data Registry registrants receiving first-time ICDs for primary prevention, the majority met trial-based criteria. Multivariate analyses suggested that many patients who did not meet the trial-based criteria may have had clinical circumstances that warranted ICD implantation. These findings caution against the use of trial-based indications to determine site quality metrics that could penalize sites that care for younger patients. The planned incorporation of appropriate use criteria into the ICD registry may better characterize patient- and site-level quality and performance.
