Effect of Optimal Heart Rate on Left Ventricular Remodeling in Patients with Systolic Heart Failure Following Acute Coronary Syndrome A Proof of Concept Study

The optimal therapeutic approach to facilitate reverse remodeling is desired in patients with systolic heart failure following acute coronary syndrome (ACS). The association between heart rate (HR) and reverse remodeling in this cohort has remained elusive. Patients with left ventricular ejection fraction (LVEF) < 50% who received echocardiography assessments following ACS were retrospectively included. Theoretically ideal HR was calculated using a previously established formula: 93-0.13 × (deceleration time [msec]). Impacts of HR on echocardiographic left ventricular (LV) reverse remodeling during the 2-year observational period were compared between 2 groups stratified by the HR difference between theoretically ideal and actual values: optimal HR group (HR difference ≤10 bpm) versus sub-optimal HR group (HR difference > 10 bpm). A total of 27 patients (median 72 years old, 23 males) were included. There were no significant differences in the baseline characteristics including maximum serum creatinine kinase level and the dose of beta-blocker between the 2 groups. LV ejection fraction increased significantly only in the optimal HR group at follow-up (from 42% to 54%; P = 0.001). The optimal HR group exhibited a more pronounced decrease in LV end-diastolic diameter (from 57 to 52 mm) compared to the sub-optimal HR group (from 58 to 56 mm). Optimal HR, which was calculated using a previously proposed formula, was associated with more substantial post-infarct LV reverse remodeling. The implications of aggressive HR modulation targeting theoretically ideal HR among those with systolic heart failure following ACS are the focus of our investigation here.