Early administration of ivabradine in patients with acute anterior ST-elevation myocardial infarction: a prospective, randomized, open-label study on in-hospital and short-term major adverse cardiac events and left ventricular function

BACKGROUND: Elevated heart rate (HR) in acute anterior ST-elevation myocardial infarction (STEMI) increases myocardial oxygen demand and limits perfusion, worsening outcomes. Ivabradine selectively reduces HR without negative inotropy. This open-label randomized controlled study investigates the efficacy and safety of early ivabradine administration in patients with acute anterior STEMI. METHODS: This randomized controlled prospective study included 300 patients with acute anterior STEMI (sinus rhythm, HR > 70 bpm) at Ain Shams University hospitals. Patients were randomized 1:1 to receive either standard beta-blocker therapy plus ivabradine (Ivabradine group, n = 150) or standard beta-blocker therapy alone (Control group, n = 150). Echocardiographic assessors and clinical event adjudicators were blinded to treatment allocation. Primary outcomes were changes in left ventricular ejection fraction (LVEF), left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV), HR, cardiac biomarkers (CK-MB, Troponin), and the incidence of major adverse cardiac events (MACE) at 3-month follow-up. Procedural variables (door-to-balloon time, final TIMI flow, myocardial blush grade, no-reflow phenomenon), Killip class, arrhythmic events, and guideline-directed medical therapy use were documented. RESULTS: Baseline demographic, angiographic, and medical therapy characteristics were similar between groups. At 3 months, the Ivabradine group demonstrated a significantly greater improvement in LVEF compared to controls (mean ± SD: 51.96 ± 6.09% vs. 49.79 ± 4.47%, p < 0.001). LVEDV significantly decreased in the Ivabradine group (from 101.44 ± 13.84 mL to 83.65 ± 8.76 mL) but increased in the control group (from 100.49 ± 12.73 mL to 120.67 ± 10.15 mL) (p < 0.001 for final LVEDV between groups). Final HR was significantly lower in the Ivabradine group (62.31 ± 1.79 vs. 76.13 ± 3.54 bpm, p < 0.001). The incidence of heart failure hospitalization (1.3% vs. 11.3%, p < 0.001) and total MACE (12.7% vs. 32.0%, p < 0.001) were significantly reduced in the Ivabradine group. No significant differences were observed in no-reflow rates (12.0% vs. 14.7%, p = 0.491) or ventricular arrhythmias (2.7% vs. 4.0%, p = 0.523) between groups. CONCLUSION: Early administration of ivabradine in patients with acute anterior STEMI and elevated HR without cardiogenic shock was associated with better heart-rate control and favorable short-term echocardiographic outcomes, while the clinical outcome findings require confirmation in prospectively registered, adequately powered multicenter trials. These findings apply to Killip class I-III patients; Killip class IV patients (cardiogenic shock) were excluded from this study.