Prognostic Impact of β-Blocker Dose After Acute Myocardial Infarction

Area of Science:

• Cardiology
• Clinical Medicine
• Pharmacology

Background:

• The prognostic significance of beta-blocker dosage following acute myocardial infarction (AMI) remains debated.
• Existing research lacks definitive conclusions on optimal beta-blocker dosing strategies post-AMI.

Purpose of the Study:

• To investigate the comparative clinical outcomes based on varying beta-blocker doses in patients after AMI.
• To evaluate the impact of low-dose versus high-dose beta-blocker therapy on cardiac mortality in AMI survivors.

Main Methods:

• Analysis of 11,909 patients from the Korea Acute Myocardial Infarction Registry-National Institutes of Health (KAMIR-NIH) database.
• Patients were stratified into three groups: no beta-blocker, low-dose (<25% target), and high-dose (≥25% target).
• Primary endpoint was cardiac death at one year, assessed using multivariable and inverse probability weighted analyses.

Main Results:

• Both low-dose and high-dose beta-blocker groups demonstrated significantly reduced cardiac death risk compared to the no beta-blocker group (HR 0.435 and 0.519, respectively).
• No significant difference in cardiac death risk was observed between the high-dose and low-dose beta-blocker groups (HR 1.194).
• These findings remained consistent after multivariable adjustment and inverse probability weighted analysis.

Conclusions:

• Beta-blocker utilization post-AMI confers a significant survival advantage over non-use.
• High-dose beta-blockers do not provide additional mortality benefit compared to low-dose regimens in the first year after AMI.