Impact of Cardio-Selective Beta-Blockers on Infarct Size After Acute Myocardial Infarction

The Impact of Sympathetic Drive Control With Cardio-Selective Beta-Blockers on Infarct Size After Acute Myocardial Infarction

Introduction: The effect of intravenous beta-blockers on the extent of the necrotic area, after primary percutaneous transluminal coronary angioplasty (PTCA), for acute myocardial infarction is not well established.

Purpose: The present study aims to investigate, whether the early intravenous administration of landiolol, a highly cardioselective b-blocker, reduces the extent of the necrotic area after ST-elevation myocardial infarction (STEMI).

Methods: This prospective observational cohort study will enroll patients presenting with STEMI, who undergo primary PCI and receive either intravenous landiolol or standard oral β-blocker therapy, in accordance with current European Society of Cardiology (ESC) guidelines. Eligibility will be determined by predefined inclusion and exclusion criteria. Treatment selection will be based solely on the clinical judgment of the attending cardiologist, without randomization.

Results: Final infarct size will be quantified by cardiac magnetic resonance imaging (CMR) performed at least three months after the STEMI to minimize edema-related overestimation. Myocardial function will be assessed during hospitalization using transthoracic echocardiography, including measurement of global longitudinal strain (GLS). Additional data will include serial high-sensitivity troponin and creatine phosphokinase (CPK) measurements, 24-hour continuous electrocardiographic monitoring for arrhythmia burden, and predefined safety outcomes collected throughout hospitalization.

Inclusion Criteria:

• Age between 18 and 80 years
• Patients with electrocardiogram showing ST-segment elevation ≥2 mm in 2 or more contiguous leads for more than 30 minutes
• Estimated time from symptom onset to reperfusion ≤12 hours
• Patients scheduled to undergo primary angioplasty
• Patients who have signed a consent form

Exclusion Criteria:

• Patients receiving chronic medication with beta-adrenergic blockers
• Patients with a previous myocardial infarction
• Persistent systolic blood pressure <90 mmHg
• Persistent heart rate <55 beats per minute
• Patients with Killip class III (acute pulmonary edema) or IV (cardiogenic shock) on initial examination
• 12-lead electrocardiogram with PR interval >200 milliseconds
• 12-lead electrocardiogram showing second- or third-degree atrioventricular block
• Bronchospasm requiring bronchodilator treatment
• Possible pregnancy or postpartum period
• Inability or refusal to sign the consent form