Clinical Impact of Beta Blockers in Patients with Myocardial Infarction from the Korean National Health Insurance Database

Abstract

Background and Objectives: Whether beta blockers favorably impact the clinical outcome in patients with acute myocardial infarction (AMI) remains in debate. We investigated the impact of beta blocker on major clinical outcomes during 2 years after percutaneous coronary intervention (PCI) in patients with AMI. Methods: All patients with the first AMI treated with PCI for the period of 2005 to 2014 from the Korean National Health Insurance Service claims database were enrolled. We defined the regular user as medication possession ratio (MPR) >= 80% and non-user as MPR=0%. We compared the occurrence of all cause death, myocardial infarction (MI) and stroke according to adherence of beta-blockers. A 1:1 propensity score-matching was conducted to adjust for between-group differences. Results: We identified a total 81,752 patients with met eligible criteria. At discharge, 63,885 (78%) patients were prescribed beta blockers. For 2 years follow tip period, regular users were 53,991 (66%) patients, non-users were 10,991 (13%). In the propensity score matched population, regular use of beta blocker was associated with a 36% reduced risk of composite adverse events (all death, MI or stroke) (hazard ratio [HR], 0.636; 95% confidence interval [CI], 0.555-0.728; p<0.001). Compared to no use of beta blocker, regular use significantly reduced all death (HR, 0.736; 95% CI, 0.668-0.812; p<0.001), MI (HR, 0.729; 95% CI, 0.611-0.803; p<0.001) and stroke (HR, 0.717; 95% CI, 0.650-0.791; p<0.001). Conclusions: Prescription of beta blocker in patients with AMI after PCI was sequentially increased. Continuous regular use of beta blocker for 2 years after AMI reduced major adverse events compared to no use of beta blocker.