Prognostic value of non invasive baroreflex sensitivity in chronic heart failure patients

Non-invasive baroreflex sensitivity (BRS) by the classical transfer function (TF) method very often cannot be assessed in chronic heart failure (CHF) patients, due to a lack of coherence between the heart period and the systolic pressure. On the grounds of a previous investigation, we devised a new BRS index based on the whole-band average (WBA) of the TF in the whole low-frequency band (WBA-BRS), which does not require a coherence check. In this study, we assessed the clinical relevance of this index by testing its prognostic value in a population of 149 CHF patients. During a 20± 2 months follow-up, 28 patients died or were urgently transplanted. The univariate relation of the WBA-BRS index with mortality was assessed by the Cox proportional hazards model, and survival functions were estimated using the Kaplan-Meier method. We also investigated the independent effect of WBA-BRS, adjusting for the NYHA (New York Heart Association) class, LVEF (left ventricular ejection fraction), peak V_O2 and Na⁺ . WBA-BRS showed a significant univariate association with the risk of cardiac events. When its predictive value was assessed in multivariate analysis, WBA-BRS displayed independent prognostic information (risk ratio=3.0, 95% confidence interval: 1.1-7.9, p=0.03). These preliminary data suggest that BRS assessed by a modified version of the classical TF method is a potential prognostic marker in CHF patients