Challenging the status quo: β-blockers for HF plus AF

Beta-blockers and 1-year clinical outcomes in hospitalized heart failure patients with atrial fibrillation

OBJECTIVE

To assess the association between beta-blockers and 1-year clinical outcomes in heart failure (HF) patients with atrial fibrillation (AF), and further explore this association that differs by left ventricular ejection fraction (LVEF) level.

METHODS

We enrolled hospitalized HF patients with AF from China Patient-centered Evaluative Assessment of Cardiac Events Prospective Heart Failure Study. COX proportional hazard regression models were employed to calculate hazard ratio of beta-blockers. The primary outcome was all-cause death.

RESULTS

Among 1762 HF patients with AF (756 women [41.4%]), 1041 (56%) received beta-blockers at discharge and 1272 (72.2%) had an LVEF > 40%. During one year follow up, all-cause death occurred in 305 (17.3%), cardiovascular death occurred in 203 patients (11.5%), and rehospitalizations for HF occurred in 622 patients (35.2%). After adjusting for demographic characteristics, social economic status, smoking status, medical history, anthropometric characteristics, and medications used at discharge, the use of beta-blockers at discharge was not associated with all-cause death [hazard ratio (HR): 0.86; 95% Confidence Interval (CI): 0.65−1.12; P = 0.256], cardiovascular death (HR: 0.76, 95% CI: 0.52−1.11; P = 0.160), or the composite outcome of all-cause death and HF rehospitalization (HR: 0.97, 95% CI: 0.82−1.14; P = 0.687) in the entire cohort. There were no significant interactions between use of beta-blockers at discharge and LVEF with respect to all-cause death, cardiovascular death, or composite outcome. In the adjusted models, the use of beta-blockers at discharge was not associated with all-cause death, cardiovascular death, or composite outcome across the different levels of LVEF: reduced (< 40%), mid-range (40%−49%), or preserved LVEF (≥ 50%).

CONCLUSION

Among HF patients with AF, the use of beta-blockers at discharge was not associated with 1-year clinical outcomes, regardless of LVEF.

How Heart Rate Should Be Controlled in Patients with Atherosclerosis and Heart Failure

PURPOSE OF REVIEW

Resting heart rate is an independent risk factor for all-cause and cardiovascular mortality in patients with heart failure. The main objectives are to discuss the prognosis of heart rate, its association with coronary atherosclerosis, and the modalities of control of the heart rate in sinus rhythm and in the rhythm of atrial fibrillation in patients with chronic heart failure.

RECENT FINDINGS

As a therapeutic option for control heart rate, medications such as beta-blockers, digoxin, and finally ivabradine have been studied. Non-dihydropyridine calcium channel blockers are contraindicated in patients with heart failure and reduced ejection fraction. The influence of the magnitude of heart rate reduction and beta-blocker dose on morbidity and mortality will be discussed. Regarding the patients with heart failure and atrial fibrillation, there are different findings in heart rate control with the use of a beta-blocker. Patients eligible for ivabradine have clinical benefits and increased ejection fraction. Vagal nerve stimulation has low efficacy for the control of heart rate. Complementary therapies such as tai chi and yoga showed no effect on heart rate. In this review, we discuss the main therapeutic options for the control of heart rate in patients with atherosclerosis and heart failure. More research is needed to examine the effects of therapeutic options for heart rate control in different population types, as well as their effects on clinical outcomes and impact on morbidity and mortality.

Decreased Mortality With Beta-Blockers in Patients With Heart Failure and Coexisting Atrial Fibrillation: An AF-CHF Substudy

OBJECTIVES

The impact of beta-blockers on mortality and hospitalizations was assessed in the largest randomized trial of patients with both atrial fibrillation (AF) and heart failure with a reduced ejection fraction (HFrEF): the Atrial Fibrillation-Congestive Heart Failure trial.

BACKGROUND

Although beta-blockers are the cornerstone of therapy for HFrEF, a recent patient-level meta-analysis cast doubt on their efficacy in patients with coexisting AF.

METHODS

From a total of 1,376 subjects randomized in the AF-CHF trial, those without beta-blockers at baseline were propensity matched to a maximum of 2 exposed patients. All absolute standardized differences after matching were ≤10%. Primary analyses respected the intention-to-treat principle. In on-treatment sensitivity analyses, beta-blocker status was modeled as a time-dependent covariate.

RESULTS

Baseline characteristics were comparable among the matched cohorts (mean age 70 ± 11 years, 81% male, and mean left ventricular ejection fraction 27 ± 6%). During a median follow-up of 37 months, beta-blockers were associated with significantly lower all-cause mortality (hazard ratio [HR]: 0.721, 95% confidence interval [CI]: 0.549 to 0.945; p = 0.0180) but not hospitalizations (HR: 0.886; 95% CI: 0.715 to 1.100; p = 0.2232). Similar results were obtained in sensitivity analyses that modeled beta-blockers as a time-dependent variable (HR: 0.668 for all-cause mortality; 95% CI: 0.511 to 0.874; p = 0.0032; HR: 0.814 for hospitalizations; 95% CI: 0.653 to 1.014; p = 0.0658). There were no significant interactions between beta-blockers and patterns (i.e., persistent vs. paroxysmal) or burden of AF with respect to mortality or hospitalizations.

CONCLUSIONS

In propensity-matched analyses, beta-blockers were associated with significantly lower mortality but not hospitalizations in patients with HFrEF and AF, irrespective of the pattern or burden of AF. These results support current evidence-based recommendations for beta-blockers in patients with HFrEF, whether or not they have associated AF.