Characteristics and outcomes of patients receiving new and replacement implantable cardioverter-defibrillators: results from the NCDR

BACKGROUND: Little is known about the clinical features, procedural risks, or survival of patients receiving replacement versus new implantablecardioverter-defibrillators (ICDs). METHODS AND RESULTS: Entries in the National Cardiovascular Data Registry (NCDR) ICD Registry from 2005 through 2010 were eligible for inclusion (n=463,978). Baseline demographic data, clinical information, and procedural variables were compared between patients receiving new(n=359,993; 77.6%) and replacement (n=103,985; 22.4%) ICDs and entered into a propensity match model to determine adjusted survival rates.Patients receiving replacement ICDs were older (70.7 versus 67.5 years of age) and more likely to have atrial fibrillation (41.8% versus 31.4%; P