Prognostic Significance of Resting Heart Rate and Use of β-Blockers in Atrial Fibrillation and Sinus Rhythm in Patients With Heart Failure and Reduced Ejection Fraction

Abstract

Background— In heart failure and reduced ejection fraction, the prognostic role of heart rate (HR) in atrial fibrillation (AF) is unknown and the effectiveness of β-blockers has recently been questioned in AF. Methods and Results— A total of 18 858 patients with heart failure and reduced ejection fraction registered with Swedish Heart Failure Registry were included in this study: patients with sinus rhythm (SR; n=11 466) and patients with AF (n=7392). The outcome measure was all-cause mortality. Compared with HR ≤60 beats per minute, the adjusted hazard ratios for mortality in SR were 1.26 for HR=61 to 70 beats per minute, 1.37 for HR=71 to 80 beats per minute, 1.52 for HR=81 to 90 beats per minute, 1.63 for HR=91 to 100 beats per minute, and 2.69 for HR >100 beats per minute. However, in AF, the hazard ratio increased only for HR >100 beats per minute (1.30; P =0.001). β-blocker use was associated with reduced mortality in SR (hazard ratio, 0.77; P =0.011) and in AF (hazard ratio, 0·71; P <0.001). For β-blocker use in SR, the hazard ratio gradually increased with HR increment, whereas in AF, the hazard ratio significantly increased only for HR >100 beats per minute (1.29; P =0.003) compared with HR ≤60 beats per minute. Conclusions— In patients with heart failure and reduced ejection fraction, a higher HR was associated with increased mortality in SR, but in AF, this is true only for HR >100 beats per minute. β-blocker use was associated with reduced mortality both in SR and in AF.