Insufficient Reduction in Heart Rate During Hospitalization Despite Beta-Blocker Treatment in Acute Decompensated Heart Failure: Insights from the ASCEND-HF Trial

AIMS: Heart failure (HF) can be associated with a higher resting heart rate (HR), and an elevated HR is associated with adverse long-term events. However, the mechanistic and causal role of HR in HF is unclear. This study aimed to investigate changes in HR during hospitalization, and the association between discharge HR and clinical outcomes as well as an interaction with beta-blocker therapy in patients with acute decompensated HF (ADHF). METHODS AND RESULTS: We studied 2906 patients with an LVEF ≤35%, without AF, who were enrolled in the ASCEND-HF trial. A total of 2492 (85.8%) patients had a HR ≥70 b.p.m. at baseline and 1580 (54.4%) patients were on beta-blocker treatment. Although HR was gradually reduced from baseline to discharge (85.5 ± 15.9 b.p.m. at baseline, 81.7 ± 14.1 b.p.m. at 24 h from treatment initiation, and 79.1 ± 12.2 b.p.m. at discharge), 80.2% of the patients still had a HR ≥70 b.p.m. at discharge. Patients with a HR ≥70 b.p.m. at discharge had significantly lower survival rates than those with a HR <70 b.p.m. (adjusted hazard ratio 1.02, 95% confidence interval 1.01-1.04, P = 0.002). Moreover, HR at discharge had a curvilinear association with mortality, and had no significant interaction effect with beta-blocker therapy at discharge (P = 0.82). CONCLUSIONS: Despite current beta-blocker therapy, many patients with hospitalized ADHF with reduced LVEF have relatively high discharge HR, and discharge HR is associated with higher mortality. Further studies are warranted to determine the optimal strategy for HR control to improve outcomes.