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 heart period and systolic pressure. On the grounds of a previous investigation, we devised a new BRS index based on the average of the TF in the whole low frequency band (WBA-BRS), which does not require 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 +/- 12 months follow-up, 28 patients died or were urgently transplanted. Univariate relation of WBA-BRS 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 NYHA class, LVEF, peak VO2, 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%Cl: 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.