Abstract
AIMS: Current guidelines recommend beta-blocker therapy in chronic heart failure with reduced ejection fraction (HFrEF) titrated according to tolerated target dose. The efficiency of this strategy to obtain adequate heart rate (HR) control remains unclear in clinical practice. The aim of this study was to determine, in a real-world setting, the proportion of HFrEF patients who fail to achieve beta-blocker target doses, whether target doses of beta-blockers have a relationship with the adequacy in reducing resting HR over time. METHODS AND RESULTS: Beta-blocker dose and resting HR of consecutive ambulatory patients with a diagnosis of HFrEF (ejection fraction ≤ 35%) in sinus rhythm were reviewed at the first outpatient contact in the Cleveland Clinic Health System from the year 2000 to 2015. Patients who did not receive beta-blocker therapy, have congenital heart disease and hypertrophic cardiomyopathy, were not in sinus rhythm, or have a history of heart transplant were excluded. Patients were followed up until their last known visit at the Cleveland Clinic. Median resting HR was 71 b.p.m. [inter-quartile range (IQR) 60-84 b.p.m.] in 8041 patients (median age 65; 68% male) with 67% on carvedilol, 32% on metoprolol succinate, and 1% on bisoprolol. In 3674 subjects (56%), resting HR was ≥70 b.p.m. At final follow-up after a median of 21 months (IQR 0.1-7.2 years), resting HR was 72 b.p.m. (IQR 60-84 b.p.m.) in the subset of patients with persistently low ejection fraction ≤ 35%. HR ≥ 70 b.p.m. was observed in 55% of this group. Beta-blocker target dose was achieved in 19%, 5%, and 15% of those receiving carvedilol, metoprolol succinate, and bisoprolol, respectively. In the subset of patients who experienced beta-blocker up-titration, reduced mortality or hospitalization due to heart failure was observed in patients who experienced the lowest HR after titration. CONCLUSIONS: In our single-centre experience, the majority of patients with chronic HFrEF treated with beta-blocker therapy did not achieve target doses over time, and a substantial proportion had inadequate control of resting HR. There was no relationship between achieved beta-blocker target dose and resting HR control.