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Meta-analysis: beta-blocker dose, heart rate reduction, and death in patients with heart failure
Finlay A McAlister1, Natasha Wiebe, Justin A Ezekowitz
1University of Alberta Hospital, 2F1.21 Walter Mackenzie Health Sciences Centre, 8440 112 Street, Edmonton, Alberta, Canada. finlay.mcalister@ualberta.ca
Insights
Beta-blockers improve survival in heart failure patients. The survival benefit is linked to heart rate reduction, not the beta-blocker dose. Achieving a lower heart rate is key for better outcomes.
Area of Science:
- Cardiology
- Pharmacology
- Clinical Trials
Background:
- Current guidelines recommend specific beta-blocker doses for heart failure patients based on trial efficacy.
- While beta-blockade adverse effects are dose-dependent, the relationship between beta-blocker dose and survival benefit in heart failure remains unclear.
Purpose of the Study:
- To investigate whether the survival benefits of beta-blocker therapy in heart failure are associated with the achieved reduction in heart rate or the administered beta-blocker dose.
- To clarify the optimal therapeutic strategy for beta-blocker use in heart failure management.
Main Methods:
- A systematic review and meta-analysis of randomized, placebo-controlled heart failure trials reporting all-cause mortality.
- Data extraction included study characteristics, beta-blocker dosing, heart rate reduction, and mortality outcomes.
- Searches were conducted across multiple databases (MEDLINE, EMBASE, CINAHL, SIGLE, Web of Science, Cochrane Central Register).
Main Results:
- Analysis of 23 trials involving 19,209 patients with systolic dysfunction showed an overall reduced risk ratio for death (0.76).
- Moderate heterogeneity was observed among trials (I² = 30%), significantly associated with the magnitude of heart rate reduction (P=0.006).
- Each 5 beats/min reduction in heart rate correlated with an 18% decrease in mortality risk; no significant association was found between beta-blocker dose and mortality.
Conclusions:
- The magnitude of heart rate reduction achieved with beta-blocker therapy is significantly associated with survival benefits in heart failure.
- Beta-blocker dosage itself was not significantly associated with the observed survival benefits in this meta-analysis.
- Findings suggest focusing on achieving heart rate reduction rather than solely on high-dose titration for optimal outcomes in heart failure.
Background:
Guidelines recommend that patients with heart failure receive beta-blockers in doses used in the trials that have proven their efficacy. Although the adverse effects of beta-blockade are dose-related, it is unclear whether the benefits are.
Purpose:
To determine whether the survival benefits of beta-blockade in heart failure are associated with the magnitude of heart rate reduction or the beta-blocker dose.
Data Sources:
MEDLINE, EMBASE, CINAHL, SIGLE, Web of Science, and the Cochrane Central Register of Controlled Trials, supplemented by hand-searches of bibliographies.
Study Selection:
Randomized, placebo-controlled heart failure trials that reported all-cause mortality.
Data Extraction:
Two reviewers independently extracted data on study characteristics, beta-blocker dosing and heart rate reduction, and death.
Data Synthesis:
The mean left ventricular ejection fraction in the 23 beta-blocker trials ranged from 0.17 to 0.36, and more than 95% of the 19 209 patients had systolic dysfunction. The overall risk ratio for death was 0.76 (95% CI, 0.68 to 0.84); however, heterogeneity testing revealed moderate heterogeneity among trials (I (2) = 30%), which was associated with the magnitude of heart rate reduction achieved within each trial (P for meta-regression = 0.006). For every heart rate reduction of 5 beats/min with beta-blocker treatment, a commensurate 18% reduction (CI, 6% to 29%) in the risk for death occurred. No significant relationship between all-cause mortality and beta-blocker dosing was observed (risk ratio for death, 0.74 [CI, 0.64 to 0.86]) in high-dose beta-blocker trials vs. 0.78 [CI, 0.63 to 0.96] in low-dose beta-blocker trials; P for meta-regression = 0.69).
Limitations:
The analysis is based on aggregate data and resting heart rates. Few patients in these trials had bradycardia or diastolic dysfunction at baseline.
Conclusion:
The magnitude of heart rate reduction is statistically significantly associated with the survival benefit of beta-blockers in heart failure, whereas the dose of beta-blocker is not.
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