Abstract 17223: The Risk of Ventricular Tachyarrhythmias or Death in Black and White Cardiac Patients - a MADIT-CRT Sub-Study
Background: Previous sub-study from MADIT-CRT showed attenuated effect of cardiac resynchronization therapy (CRT) in blacks vs. whites to reduce heart failure or death. However, the effect of race on ventricular tachyarrhythmias (VTA) is unknown.
Objectives: This study sought to analyze the risk of life threatening ventricular tachyarrhythmias or death in black and white subjects implanted with implantable cardioverter defibrillators (ICD) or defibrillator and combined cardiac resynchronization therapy (CRT-D), enrolled in MADIT-CRT.
Hypothesis: We hypothesized that black patients have a higher risk of VTA’s or death, independent of treatment assignment.
Methods: The risk for first VTA’s (<180 beats/min) or death was evaluated in black versus white patients using Kaplan-Meier survival analyses and Cox proportional hazards regression models after adjustment for relevant clinical covariates.
Results: A total of 139 (8%) black patients were included in the current analysis of which 84 (60%) received a CRT-D. At 2.5-years of follow-up, 32% of the black vs. 22% of the white patients had first VTA or death (see Figure, p log-rank=0.006), and 26% of blacks vs. 18% of whites had VTA’s (p log-rank=0.015). Multivariate analysis confirmed the significantly higher risk of VTA or death (HR=1.60, 95% CI: 1.18-2.17, p=0.002), and higher risk of VTA alone (HR=1.71, 95% CI: 1.22-2.41, p=0.002) in blacks compared to whites. The findings were similar in both ICD and CRT-D implanted patients, with no significant race-to-treatment-interaction (interaction p-values > 0.10).
Conclusion: In MADIT-CRT, black patients had a significantly higher rate of ventricular tachyarrhythmias or death compared to whites, with either an implanted ICD or a CRT-D.
Author Disclosures: A. sabbag: None. I. Goldenberg: None. A. Moss: None. S. McNitt: None. S. Polonsky: None. W. Zareba: None. V. Kutyifa: Research Grant; Significant; Boston Scientific, Zoll.
- © 2014 by American Heart Association, Inc.