Prognostic Role of Minimum Heart Rate in Elderly Heart Failure Patients with Hypertensive Heart Disease: An Analysis of MIMIC-IV Database

Background Heart rate has been documented as a predictive factor in heart failure. However, its prognostic role in specific heart failure patients are diverse and not comprehensively identified. Methods A retrospective cohort study was conducted based onthe MIMIC-IV database. 2476 elderly (³ 60 years old) patients with heart failure and hypertensive heart disease were recruited. The participants were divided into a low minimum heart rate (MHR) (< 60 bpm) group and a high MHR (³ 60 bpm) group. Multivariable Cox proportional hazards regression analysis was implemented to evaluate the relationship between the two MHR groups and mortality. The association between prognosis and MHR as a continuous variable was elucidated via the restricted cubic spline model. The association in subgroups was assessed as well. Results Compared with high MHR, low MHR was significantly associated with higher 30-day all-cause mortalities (hazard ratio 1.309, 95% confidence interval 1.061 to 1.615, p = 0.012), 90-day all-cause mortality (hazard ratio 1.221, 95% confidence interval 1.020 to 1.462, p = 0.03), and 1-year all-cause mortality (hazard ratio 1.197, 95% confidence interval 1.028 to 1.393, p = 0.02) after adjustment for confounding variables. A U-shaped relationship between outcomes and MHR as a continuous variable was observed, with a nadir at MHR of approximately 50 to 60 bpm. The predictive value of low MHR was significant in women, but not in men. Conclusions We demonstratedthat MHR plays a prognostic role in elderly patients with heart failure and hypertensive heart disease. Low MHR predicts higher all-cause mortality, and the association conforms to a U-shaped pattern. Our findings extend those of previous studies and suggest the potential predictive value of HR in specific heart failure patients.