Angiotensin receptor blocker in patients with ST segment elevation myocardial infarction with preserved left ventricular systolic function: prospective cohort study

Objective To investigate the association between treatment with an angiotensin receptor blocker and clinical outcomes in patients with ST segment elevation myocardial infarction with preserved left ventricular systolic function. Design A prospective cohort study using data from a nationwide large scale registry. Setting 53 hospitals involved in treatment of acute myocardial infarction in Korea. Participants Between November 2005 and September 2010, we studied 6698 patients with ST segment elevation myocardial infarction who underwent primary percutaneous coronary intervention and had a left ventricular ejection fraction >= 40%. Main outcome measures Cardiac death or myocardial infarction. Patients were divided into an angiotensin receptor blocker group (n=1185), an angiotensin converting enzyme (ACE) inhibitor group (n=4564), and a group who did not receive any renin angiotensin system blocker (n=949). Propensity score matching analysis was also performed. Results Cardiac death or myocardial infarction occurred in 21 patients (1.8%) in the angiotensin receptor blocker group, 77 patients (1.7%) in the ACE inhibitor group, and 33 patients (3.5%) in the no renin angiotensin system blocker group. After propensity score matching (1175 pairs), there was no significant difference in the rate of cardiac death or myocardial infarction between the angiotensin receptor blocker group and ACE inhibitor group (21 (1.8%) v 23 (2.0%), adjusted hazard ratio 0.65, 95% confidence interval 0.30 to 1.38; P=0.65). The angiotensin receptor blocker group had a lower rate of cardiac death or myocardial infarction than the no renin angiotensin system blocker group in matched populations (803 pairs) (14 (1.7%) v 25 (3.1%), 0.35, 0.14 to 0.90; P=0.03). Conclusion Angiotensin receptor blocker showed beneficial effects comparable with ACE inhibitors in patients with ST segment elevation myocardial infarction with preserved left ventricular systolic function. Angiotensin receptor blockers could be used as an alternative to ACE inhibitors in such patients.