PROGNOSTIC VALUE OF HEART-RATE-VARIABILITY DURING LONG-TERM FOLLOW-UPIN PATIENTS WITH MILD-TO-MODERATE HEART-FAILURE

Objectives. We sought to assess the prognostic value of heart rate var iability measures, including Poincare plots, in patients with mild to moderate chronic heart failure. Background. Mortality is high in patie nts with heart failure, and many of them die suddenly. However, identi fication of high risk patients, particularly those,vith an increased r isk for sudden death, has remained difficult. Methods. We studied 95 p atients with heart failure (mean [+/-SD] age 60 +/- 8 years, left vent ricular ejection fraction 0.29 +/- 0.09, Nea York Heart Association fu nctional class II [81%] and III [19%]) during up to 4 years of follow- up. Heart rate variability measures and Poincare plots were obtained f rom 24-h Holter recordings. Results. During follow up, 17 (18%) of the 95 patients died. In 15 patients, death was cardiac related (11 patie nts experienced sudden death). None of the conventional time and frequ ency domain measures of heart rate variability were related to surviva l. In contrast, abnormal Poincare plots identified a significantly hig her risk for all-cause cardiac death (Cox proportional hazards ratio 5 .7, 95% confidence interval [CI] 1.6 to 20.6, univariate analysis);Ind for sudden cardiac death (hazards ratio 6.8, 95% CI 1.5 to 31.4) comp ared with those with normal Poincare plots. Patients with abnormal Poi ncare plots were shown to have a lower left ventricular ejection fract ion (0.26 +/- 0.10 vs. 0.31 +/- 0.08, p < 0.05) and higher plasma nore pinephrine concentrations (506 +/- 207 pg/ml vs. 411 +/- 175 pg/ml, p < 0.05). In multivariate analysis, abnormal Poincare plots still had i ndependent prognostic value, both for all cause cardiac mortality and for sudden cardiac death (hazards ratio 5.3, 95% CI 1.2 to 17.1, hazar ds ratio 4.5, 95% CI 1.0 to 27.5, respectively. Conclusions. Heart rat e variability analysis, as assessed by Poincare plots, has independent prognostic value in patients with mild to moderate chronic heart fail ure and identifies an increased risk for all cause and sudden cardiac death in these patients.