Survival of Patients With Implantable Cardioverter Defibrillators in the Era of Remote-Monitoring: The 5000-Foot, High-Altitude View

Large randomized trials have demonstrated unequivocally that implantable cardioverter defibrillators (ICDs) improve outcome for individuals with defined clinical characteristics known to be associated with a high risk of ventricular arrhythmias. However, less is known about outcomes of patients receiving ICDs in the “real world.” The National Cardiovascular Data Registry provides extensive and detailed clinical information about patients receiving ICDs at the time of implant, but does not include longitudinal data on mortality or shocks except in a small subset.1 Industry databases of ICD patients undergoing remote (transtelephonic) monitoring, which provide extensive information on therapies received, thus present a unique opportunity to fill this gap in knowledge.Article see p 2359In this issue of Circulation , Saxon et al2 describe data on 69 556 patients followed remotely (in addition to in-office) and 124 450 patients followed in-office alone, which was generated by the Altitude project, a prospectively designed database generated by a single ICD manufacturer to store data regarding patients receiving its devices. Survival data are obtained through cross-referencing with the Social Security death index, and data on treated arrhythmias are obtained from the transtelephonic transmissions. The authors use this database to answer four distinct questions: (1) whether remote monitoring impacts survival; (2) whether shocks are associated with mortality; (3) how survival compares among patients receiving ICDs, ICDs with cardiac resynchronization (CRT) capability (CRT-D), and CRT devices without defibrillation capability; and (4) how survival of “real-world” patients compares with that of patients enrolled in trials. The study is limited by lack of detailed information about the patients' …