Elevated Resting Heart Rate in Hospitalized Patients With Atrial Fibrillation Is Associated With Increased Cardiovascular Risk

Background: Effective rate control is important in the management of atrial fibrillation (AF). However, the relationship between resting heart rate (RHR) and adverse outcomes in hospitalized patients remains uncertain. Objective: This study was to evaluate the association between RHR and in-hospital outcomes. Methods: Data from the Improving Care for Cardiovascular Disease in China-AF project from 2014 to 2019 were retrospectively analyzed. The primary outcome was the composite of in-hospital all-cause mortality and in-hospital acute heart failure (AHF). Secondary outcomes included stroke/transient ischemic attack (TIA) and bleeding during hospitalization. Logistic regression analyses were used to assess the association between RHR and outcomes. Results: Our study included 12,775 patients hospitalized for AF in 236 hospitals. Logistic regression analyses using different models showed a significant association between RHR exceeding 80 bpm and an increased risk of the primary outcome (adjusted OR: 1.79 [95% CI: 1.44–2.22]). A positive association between RHR and the primary outcome was identified with RHR ≥ 80 bpm. Marginal effect analyses showed that patients with advanced AF types were at higher risk across the range of RHR. Conversely, catheter ablation, but not antiarrhythmic drug use, was associated with a decreased risk. Conclusion: A significant association was identified between RHR and adverse outcomes in patients hospitalized for AF, where RHR exceeding 80 bpm was associated with an increased risk. Trial Registration: ClinicalTrials.gov identifier: NCT02309398.