Rhythm-specific heart rate thresholds during the vulnerable period: integrated analysis for prognostic optimization in heart failure.

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.