Comparison of Early Vs Delayed Beta Blocker Initiation in Acute Myocardial Infarction and's impact on left ventricular ejection fraction recovery: Comparison of Early Versus Delayed Beta Blocker Initiation on LVEF Recovery in AMI

Samina  Bashir

doi:10.69750/dmls.02.010.0158

Authors

Samina Bashir Punjab Institute of Cardiology (PIC), Lahore, Pakistan Author

DOI:

https://doi.org/10.69750/dmls.02.010.0158

Keywords:

Acute myocardial infarction, Beta-blockers, Left ventricular ejection fraction, Early initiation, Cardiac remodeling, Ventricular arrhythmia

Abstract

Background: Beta-blockers are an established cornerstone in the management of acute myocardial infarction (AMI) due to their cardioprotective, antiarrhythmic, and anti-remodeling effects. However, the optimal timing of their initiation remains clinically debated, particularly regarding their impact on the recovery of left ventricular ejection fraction (LVEF).

Objective: To compare early (within 24 hours) versus delayed (after 72 hours) initiation of beta-blockers in patients with acute myocardial infarction and to assess their effects on LVEF recovery and short-term clinical outcomes.

Methods: This comparative cross-sectional study was conducted at the Punjab Institute of Cardiology, Lahore, Pakistan, from July 2024 to July 2025. A total of 70 patients aged 35–70 years with confirmed AMI were enrolled and divided equally into two groups. Group A received beta-blockers within 24 hours, while Group B received them after 72 hours. LVEF was measured using echocardiography at baseline and at three-month follow-up. Secondary outcomes included arrhythmias, readmissions, and mortality.

Results: Baseline characteristics were similar between groups. Mean LVEF improved significantly in Group A (38.5 ± 5.3% to 49.8 ± 6.2%) compared to Group B (38.9 ± 5.1% to 44.1 ± 5.9%, p < 0.001). Early initiation also reduced ventricular arrhythmias (5.7% vs. 17.1%) and readmission rates (8.6% vs. 20%). No significant differences in bradycardia or hypotension were noted.

Conclusion: Early initiation of beta-blockers within 24 hours after AMI leads to superior LVEF recovery and fewer arrhythmic events compared to delayed therapy. Early beta-blockade should be encouraged in all hemodynamically stable AMI patients.

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