Arterial baroreflex modulation of heart rate in chronic heart failure: Clinical and hemodynamic correlates and prognostic implications

Background: In chronic heart failure (CHF), arterial baroreflex regulation of cardiac function is impaired, leading to a reduction in the tonic restraining influence on the sympathetic nervous system. Because baroreflex sensitivity (BRS), as assessed by the phenylephrine technique, significantly contributes to postinfarction risk stratification, the aim of the present study was to evaluate whether in CHF patients a depressed BRS is associated with a worse clinical hemodynamic status and unfavorable outcome. Methods and Results: BRS was assessed in 282 CHF patients in sinus rhythm receiving stable medical therapy (age, 52 ± 9 years; New York Heart Association [NYHA] class, 2.4 ± 0.6; left ventricular ejection fraction [LVEF], 23 ± 6%). The BRS of the entire population average 3.9 ± 4.0 ms/mm Hg (mean ± SD) and was significantly related to LVEF and hemodynamic parameters (LVEF, P3 ms/mm Hg). During a mean follow-up of 15 ± 12 months, 78 primary events (cardiac death, nonfatal cardiac arrest, and status 1 priority transplantation) occurred (27.6%). BRS was significantly related to outcome (log rank, 9.1; P