Abstract 13236: Prognostic Value of Heart Rate Depends on the Degree of Beta-Adrenergic Blockade in Chronic Heart Failure Patients with Reduced Ejection Fraction
Background: The BEAUTIFUL-study has shown that a heart rate >70 bpm is associated with a worse prognosis in patients with ischemic heart disease and reduced ejection fraction. This finding supported the rationale of the SHIfT-trial which investigated the effects of selective heart rate reduction by ivabradine on top of optimized beta-blocker therapy in heart failure patients with reduced ejection fraction. Since the degree of beta-blockade might influence the prognostic importance of heart rate and thus the effectiveness of selective heart rate reduction on outcome, we evaluated the prognostic power of heart rate at different levels of beta-blockade.
Methods: 642 chronic heart failure patients (17% female, age 59±13y, LVEF <40%) were subgrouped according to their beta-blocker medication in terms of percent recommended target dose: low: 6%–25% (n=236), intermediate: 26%–75% (n=243), high: >75% (n=163).
Results: 246 (38%) patients died after a follow-up period of 60months. We found a significant, positive interaction (p=0.026) between high heart rate and beta-blocker dosage showing that the power of heart rate >70 bpm to predict mortality increases as the beta-blocker dosage increases. Although in the total population high heart rate alone was not significantly associated with mortality risk, in the subgroup of patients with highest beta blockade high heart rate was a significant predictor of mortality (HR: 1.709 [1.061–2.754], p=0.0276), in contrast to patients with intermediate (HR: 1.151 [0.722–1.836], p=0.5536) and low beta-blocker dosages (HR: 0.992 [0.621–1.366], p=0.683).
Conclusions: The prognostic importance of elevated heart rate in patients with chronic heart failure and reduced ejection fraction depends on beta-blocker dosage. The prognostic power of heart rate was only apparent in patients with highest doses of beta-blocker medication. These findings might be useful in interpreting the results of the SHIfT-Trial and in estimating the potential benefit of selective heart rate reduction in chronic heart failure.
- © 2010 by American Heart Association, Inc.