Abstract
BACKGROUND: Heart rate control during the vulnerable period (1-3 months post-discharge) is critical for improving outcomes in heart failure (HF). Prognostic implications for sinus rhythm (SR) versus atrial fibrillation (AF) patients remain unestablished. METHODS: We conducted an observational study of 438 heart failure patients to evaluate heart rate associations with HF readmission and all-cause mortality, alongside analysis of MIMIC-III database records assessing vulnerable period mortality relationships. This primary investigation was supplemented by systematic review and meta-analysis of cohort studies and randomized trials from PubMed, Embase, and Cochrane Library databases through February 2025 examining heart rate-prognosis correlations during the vulnerable period. RESULTS: The observational study demonstrated that, in SR patients, heart rates < 76 bpm at 1 month reduced mortality (P = 0.008), while 77-129 bpm increased HF readmission (P < 0.05) and composite all-cause mortality and/or HF readmission risk. AF patients with rates < 71 bpm at 3 months reduced HF readmission and or mortality (P < 0.05). MIMIC-III analysis confirmed that the mortality risk for SR increased with rates > 94 bpm (P = 0.037). Meta-analysis (6 studies) indicated elevated mortality (HR = 1.20, 95%: CI 0.98-1.46) and readmission risk (HR = 1.25, 95% CI: 0.88-1.79) at higher rates. CONCLUSIONS: Maintaining heart rates < 77 bpm (SR) and < 71 bpm (AF) during the vulnerable period reduces readmission and mortality. These thresholds provide clinically actionable guidance for rhythm-stratified heart rate management in HF.