Abstract 13060: Assessment of Baroreflex Sensitivity by Bivariate Phase-Rectified Signal Averaging and Prediction of Mortality Post Myocardial Infarction
Background: Assessment of spontaneous baroreflex sensitivity (BRS) provides prognostic information in post-myocardial infarction (MI) patients. Fully noninvasive methods for BRS assessment were proposed. However, they are limited by non-stationarities and noise in both ECG and arterial pressure signals. We validate a novel method of assessing spontaneous BRS based on bivariate Phase-Rectified Signal Averaging (BRSPRSA) in a cohort of post MI patients.
Methods: A two-hospital, observational, prospective study of 941 survivors of acute MI aged ≤ 80 years who presented with sinus rhythm underwent 30-minute recordings of ECG and arterial blood pressures (BP, Portapres) within the first 2 weeks after MI. BRSPRSA was assessed according to a previously published technology and prospectively dichotomized at 1.14ms. Primary end-point was total mortality within 5 years. Multivariate analyses included BRSPRSA ≤1.14ms versus >1.14ms, LVEF ≤35% versus >35%, age ≥65 years versus 1.14ms) with a 5-year mortality of 3.8% (p<0.0001). On multivariate analysis, BRSPRSA ≤1.14ms was a strong and independent predictor of death. Predictive power of BRSPRSA ≤1.14ms was particularly strong in patients with LVEF ≤35% in whom it indicated a 35.8% risk of death (see Figure, p<0.0001).
Conclusion: BRSPRSA is a novel method to assess BRS and has a strong and independent predictive value of mortality in survivors of MI. It can provide additional stratification benefits when combined with current established risk predictors to identify individuals at greatest risk for sudden cardiac death post MI.
- Autonomic nervous system
- Reflexes, cardiovascular
- Ejection fraction
- Heart rate/Heart rate variability
- Myocardial infarction
- © 2010 by American Heart Association, Inc.