Heart Rate and Prognosis of Heart Failure with Reduced Ejection Fraction in Women and Men in Sinus Rhythm

<b>Background</b>: A resting heart rate (RHR) is a guideline-recommended therapeutic target for all patients with heart failure with reduced ejection fraction (HFrEF), with reductions to 60 bpm linked to improved outcomes. Conversely, elevated RHR is associated with increased mortality in HFrEF. However, sex-specific differences in mortality, particularly for women in sinus rhythm, remain unclear. We evaluated mortality rates at RHR thresholds of ≤60 bpm and ≤70 bpm in women and men with HFrEF. <b>Methods</b>: From February 2017 to January 2022, we assessed 2984 patients (61 ± 13.8 years, 64.4% men) with HFrEF in sinus rhythm. Clinical and echocardiographic data were analyzed to examine RHR's influence on mortality. <b>Results</b>: Over a mean follow-up of 3.7 ± 1.6 years, left ventricular ejection fraction improved in men (29.5 ± 6.7% to 36.7 ± 12.9%; <i>p</i> < 0.001) and women (29.9 ± 6.4% to 38.0 ± 13.4%; <i>p</i> < 0.001). Men had higher mortality (43.7% vs. 36.7%; <i>p</i> < 0.001), with cumulative death incidence greater at an RHR > 60 bpm (<i>p</i> < 0.001) and >70 bpm (<i>p</i> = 0.011). Cox regression identified an RHR as an independent predictor of mortality for men (HR = 1.008; <i>p</i> = 0.008) but not women. <b>Conclusions</b>: An elevated RHR increases mortality risk in men, suggesting a target near 60 bpm and closer to 70 bpm in women, supporting individualized RHR management.