Resting heart rate and outcomes in patients with heart failure: impact of AF from the Thai-Heat Failure Registry (THFR - HRAF study)

Abstract Introduction Heart rate (HR) is a significant prognosis factor and target of the treatment in patients with heart failure (HF) but this relationship in heart failure patients with atrial fibrillation (AF) is uncertain. Methods A total of 2,996 patients with HF were enroll in the Thai-Heart Failure registry between 2023 to 2024, from 37 heart failure clinics in Thailand. Patients were classified by resting HR and whether having AF or not. The primary outcomes are all-cause death and/or HF. The continuous prognostic relationship and interaction were determined by Cubic-spline model. Results Total of 2,932 patients with available resting heart rate and AF status were analyzed (mean age 59.3±14.5 years, 67.9% male, mean LVEF 31.9%, 12.4% having AF). There were 273, 1,497, 895 and 267 patients have HR <60, 60-80, 80-100 and >100 bpm, respectively. From the lowest HR to the highest group, the all-cause death and/or HF were 16.5%, 10.4% 13.7% and 14.0%. Interestingly, the patients in the lowest, high and highest HR group were associated with poorer outcomes when compared to patients with normal HR (60-80 bpm). (p <0.001, 0.004 and 0.033, respectively). There were no statistic significances in patient with LVEF >40% (p= 0.37, 0.48 and 0.41, respectively). The hazard ratio is lowest between 64 to 91 bpm. The relationship is the same in patient with AF (p for interaction 0.071) but higher hazard ratio at any giving heart rate. Conclusion The normal heart rate (between 60-80 bpm) is associated with the best outcomes, not lower is better. HR is a significant prognosis factor whether having AF or not. The relationship is mainly in patient with HFrEF.Figure