South Korea: The medical therapy with beta-blockers or RAS inhibitors at discharge is tied to better 2-year clinical outcomes in patients with mildly reduced left ventricular ejection fraction (EF) after acute myocardial infarction (AMI), states a recent study. The study was published in medRxiv.org as a preprint and has not yet been peer-reviewed.
There has been an increase in the number of patients with mildly reduced left ventricular ejection fraction (41 - 49%) in the era of the initial optimal interventional and medical therapy for acute myocardial infarction. Considering this, Seung-Jae Joo, Department of Internal Medicine, Jeju National University Hospital, Jeju, Republic of Korea, and colleagues aimed to investigate the association between the medical therapy with oral beta-blockers or inhibitors of the renin-angiotensin system (RAS) and 2-year clinical outcomes in patients with mildly reduced EF after AMI in an observational study.

For this purpose, propensity-score matched patients who survived the initial attack and had mildly reduced EF were selected according to beta-blocker or RAS inhibitor therapy at discharge among patients enrolled in the Korea Acute Myocardial Infarction Registry-National Institute of Health.
The study revealed the following findings:
Beta-blocker therapy at discharge was associated with lower 2-year major adverse cardiac events which was a composite of cardiac death, myocardial infarction, revascularization and re-hospitalization due to heart failure (8.7 vs. 12.8/100 patient-years; hazard ratio [HR] 0.68), and no significant interaction between EF ≤45% and >45% was observed.
This association was mainly driven by lower myocardial infarction in patients with beta-blockers (HR 0.50).
Inhibitors of RAS at discharge were associated with lower re-hospitalization due to heart failure (1.8 vs. 3.5/100 patient-years; HR 0.53) without significant interaction between EF ≤45% and >45%.
"Our findings revealed that The medical therapy with beta-blockers or RAS inhibitors at discharge in patients with mildly reduced EF after AMI was associated with better 2-year clinical outcomes without significant interaction between EF ≤45% and >45%," wrote the authors.
"The data suggest that beta-blockers and RAS inhibitors can be considered in patients with mildly reduced LVEF after an acute MI in the era of early coronary reperfusion therapy and contemporary optimal medical therapies," they concluded.
Reference:
The preprint research study titled, "Association of the medical therapy with beta-blockers or inhibitors of the renin-angiotensin system with clinical outcomes in patients with mildly reduced left ventricular ejection fraction after acute myocardial infarction," appears in medRxiv.org.
DOI: https://doi.org/10.1101/2022.03.01.22271686
KEYWORDS: medRxiv.org, beta-blockers, RAS inhibitor, myocardial infarction, discharge, left ventricular ejection fraction, EF, acute MI, Seung-Jae Joo, MI, medical therapy, LVEF