Long-Term Benefit of Early Pre-Reperfusion Metoprolol Administration in Patients With Acute Myocardial Infarction

• Published in: Journal of the American College of Cardiology Vol. 63; no. 22; pp. 2356 - 2362
• Main Authors: Pizarro, Gonzalo, Fernández-Friera, Leticia, Fuster, Valentin, Fernández-Jiménez, Rodrigo, García-Ruiz, José M., García-Álvarez, Ana, Mateos, Alonso, Barreiro, María V., Escalera, Noemí, Rodriguez, Maite D., de Miguel, Antonio, García-Lunar, Inés, Parra-Fuertes, Juan J., Sánchez-González, Javier, Pardillos, Luis, Nieto, Beatriz, Jiménez, Adriana, Abejón, Raquel, Bastante, Teresa, Martínez de Vega, Vicente, Cabrera, José A., López-Melgar, Beatriz, Guzman, Gabriela, García-Prieto, Jaime, Mirelis, Jesús G., Zamorano, José Luis, Albarrán, Agustín, Goicolea, Javier, Escaned, Javier, Pocock, Stuart, Iñiguez, Andrés, Fernández-Ortiz, Antonio, Sánchez-Brunete, Vicente, Macaya, Carlos, Ibanez, Borja
• Format: Journal Article
• Language: English
• Published: New York Elsevier Inc 10.06.2014; Elsevier Limited
• Subjects: beta-adrenergic receptors; Cardiology; Cardiovascular; Heart attacks; heart failure; ICD; infarct size; LVEF; magnetic resonance imaging; metoprolol; Mortality; myocardial infarction; NMR; Nuclear magnetic resonance; PCI; STEMI; heart failure; magnetic resonance imaging; MRI; infarct size; CI; myocardial infarction; LVEF; HR; LV; ICD; IV; pPCI; metoprolol; MACE; beta-adrenergic receptors; PCI; STEMI; primary percutaneous coronary intervention; left ventricular ejection fraction; intravenous; left ventricular; implantable cardioverter-defibrillator; major adverse cardiac event(s); hazard ratio; confidence interval; ST-segment elevation myocardial infarction
• ISSN: 0735-1097; 1558-3597
• DOI: 10.1016/j.jacc.2014.03.014

The goal of this trial was to study the long-term effects of intravenous (IV) metoprolol administration before reperfusion on left ventricular (LV) function and clinical events. Early IV metoprolol during ST-segment elevation myocardial infarction (STEMI) has been shown to reduce infarct size when used in conjunction with primary percutaneous coronary intervention (pPCI). The METOCARD-CNIC (Effect of Metoprolol in Cardioprotection During an Acute Myocardial Infarction) trial recruited 270 patients with Killip class ≤II anterior STEMI presenting early after symptom onset (<6 h) and randomized them to pre-reperfusion IV metoprolol or control group. Long-term magnetic resonance imaging (MRI) was performed on 202 patients (101 per group) 6 months after STEMI. Patients had a minimal 12-month clinical follow-up. Left ventricular ejection fraction (LVEF) at the 6 months MRI was higher after IV metoprolol (48.7 ± 9.9% vs. 45.0 ± 11.7% in control subjects; adjusted treatment effect 3.49%; 95% confidence interval [CI]: 0.44% to 6.55%; p = 0.025). The occurrence of severely depressed LVEF (≤35%) at 6 months was significantly lower in patients treated with IV metoprolol (11% vs. 27%, p = 0.006). The proportion of patients fulfilling Class I indications for an implantable cardioverter-defibrillator (ICD) was significantly lower in the IV metoprolol group (7% vs. 20%, p = 0.012). At a median follow-up of 2 years, occurrence of the pre-specified composite of death, heart failure admission, reinfarction, and malignant arrhythmias was 10.8% in the IV metoprolol group versus 18.3% in the control group, adjusted hazard ratio (HR): 0.55; 95% CI: 0.26 to 1.04; p = 0.065. Heart failure admission was significantly lower in the IV metoprolol group (HR: 0.32; 95% CI: 0.015 to 0.95; p = 0.046). In patients with anterior Killip class ≤II STEMI undergoing pPCI, early IV metoprolol before reperfusion resulted in higher long-term LVEF, reduced incidence of severe LV systolic dysfunction and ICD indications, and fewer heart failure admissions. (Effect of METOprolol in CARDioproteCtioN During an Acute Myocardial InfarCtion. The METOCARD-CNIC Trial; NCT01311700)