Abstract 12202: New York Heart Association Class and the Mortality Benefit From Primary Prevention Implantable Cardioverter Defibrillator Use: A Pooled Analysis of 4 Randomized Control Trials
Introduction: Primary prevention implantable cardioverter defibrillators (ICDs) reduce all-cause mortality by reducing sudden cardiac death. There are conflicting data regarding whether patients with more advanced heart failure (HF) derive ICD benefit owing to the competing risk of death from pump failure.
Methods: We performed a patient level data meta-analysis of 4 primary prevention ICD trials (MADIT-I, MADIT-II, DEFINITE, SCD-HeFT) to determine the effect of ICD use on all-cause mortality by NYHA class. We included ICD and control patients with EF ≤35%, NYHA II or III HF, and myocardial infarction ≥40 days prior to randomization. Bayesian-Weibull survival regression models were employed to assess the impact of the ICD on mortality among the study population and by NYHA class.
Results: Of the 2,763 patients who met study criteria, 68% (n=1,867) were NYHA II and 52% (n=1,435) were randomized to an ICD. In a multivariable model including all study patients, the ICD reduced mortality [HR 0.65, 95% posterior credibility interval (PCI) 0.40-0.99]. The interaction between NYHA class and ICD use on mortality was significant (posterior probability of no interaction = 0.036). The unadjusted effect of the ICD on mortality by NYHA class is depicted in Figures A&B. In stratified multivariable models including an interaction term for the NYHA class and ICD therapy, the ICD reduced mortality among NYHA II (HR 0.55, 95% PCI 0.35-0.85) and there was a trend toward reduced mortality in NYHA III patients (HR 0.76, 95% PCI 0.48-1.24). Between trial differences in mortality rates were observed across the NYHA III control patients (Figure C) suggesting heterogeneous risk profiles.
Conclusions: Primary prevention ICDs reduce mortality in NYHA II patients and trend towards reducing mortality in NYHA III patients. An improved understanding of the heterogeneous natural history of NYHA III patients may help improve patient selection for primary prevention ICDs in this important subgroup.
Author Disclosures: D.J. Friedman: Other; Modest; Boston Scientific, St. Jude. S.M. Al-Khatib: None. E.P. Zeitler: None. J. Han: None. G.H. Bardy: None. J.T. Bigger: None. A.E. Buxton: Research Grant; Significant; Medtronic research grant; not in this subject area. A.J. Moss: Research Grant; Significant; grant support from Boston Scientific. K.L. Lee: None. R. Steinman: None. P. Dorian: Research Grant; Modest; Bayer, BI, BMS, and Pfizer. Honoraria; Modest; Bayer, BI, BMS, and Pfizer. A. Hallstrom: None. R. Cappato: None. A.H. Kadish: None. P.J. Kudenchuk: None. D.B. Mark: Research Grant; Significant; St Jude Medical, Medtronic. L.Y. Inoue: None. G.D. Sanders: None.
- © 2016 by American Heart Association, Inc.