Abstract 317: Outcomes after Primary Prevention Implantable Cardioverter Defibrillator Placement: Results of the Cardiovascular Research Network Longitudinal Study of Implantable Cardioverter Defibrillators
Background: Implantable cardioverter defibrillators (ICDs) are commonly used for the primary prevention of sudden cardiac death. Controversies persist, however, about outcomes in representative cohorts and in clinically important patient subgroups. Observational studies of outcomes following primary prevention ICD implantation are typically limited to relatively restricted cohorts (e.g. Medicare) or with short follow up.
Methods: In the Cardiovascular Research Network (CVRN), we conducted a study in 7 integrated health care delivery systems to identify patients undergoing primary prevention ICD implantation for left ventricular systolic dysfunction between 2006-2010. Baseline procedural and clinical data were obtained from the NCDR ICD Registry; longitudinal data to ascertain outcomes after implantation were obtained through clinical health system data from the CVRN Virtual Data Warehouse. We assessed the occurrence of complications at 90 days and mortality, all-cause hospitalization, and heart failure hospitalization up to 5 years after implantation in clinical strata designated a priori. Multivariable models accounting for clustering of patients within site were used to assess the relationship between clinical variables and each outcome. Clinical variables of interest (Table) were included in all models; additional variables were assessed with forward selection to account for possible confounders.
Results: Among 2953 eligible patients, median age was 69 years and 26% were women Coexisting conditions, including hypertension (74%), atrial fibrillation (32%), COPD (20%), and diabetes (42%), were common. Overall event rates (per 1000 patient years) were 110 for death, 438 for any hospitalization, and 58 for heart failure hospitalization. The association between clinically important variables and outcomes are shown in the Table.
Conclusions: In a diverse population of patients undergoing ICD implantation in contemporary practice we identified specific clinical variables associated with adverse outcomes. These data can inform prognosis in clinical care and guide the design of future trials of this therapy.
Author Disclosures: F.A. Masoudi: H. Other; Significant; American College of Cardiology. A.S. Go: None. D.J. Magid: None. L.M. Reifler: None. K.A. Glenn: None. A.E. Cassidy-Bushrow: None. J.H. Gurwitz: None. K. Reynolds: None. D.H. Smith: None. F. Fiocchi: None. R.J. Goldberg: None. N. Gupta: None. P.N. Peterson: None. C. Schuger: None. H. Vidaillet: None. R.T. Greenlee: None.
- © 2014 by American Heart Association, Inc.