ARBs may have similar benefits to ACE inhibitors in Korean patients with STEMI and preserved left ventricular systolic function

Angiotensin-receptor blockers (ARBs) may provide benefits similar to angiotensin-converting enzyme (ACE) inhibitors in patients with ST-segment elevation myocardial infarction (STEMI) and preserved left ventricular systolic function, according to a recent study performed in Korea.

Researchers in Korea performed a prospective cohort study using data from a nationwide registry to examine the effect of ARB treatment on clinical outcomes in patients with STEMI who had primary percutaneous coronary intervention and a left ventricular ejection fraction of 40% or greater. Patients were categorized as receiving ARBs, ACE inhibitors, or no renin angiotensin system blockers. The study's main outcome measures were cardiac death or MI. Results were published online Nov. 14 by The BMJ.

A total of 6,698 patients seen between November 2005 and September 2010 were included in the study. Of these, 1,185 received ARBs (17.7%), 4,564 received ACE inhibitors (68.1%), and 949 received no renin angiotensin system blockers (14.2%). In these groups, respectively, 21 patients (1.8%), 77 patients (1.7%), and 33 patients (3.5%) experienced cardiac death or MI over a median follow-up of 371 days (interquartile range, 167 to 450 days). With propensity score matching done for 1,175 pairs, no significant difference was seen in cardiac death or MI rates between the ARB group and the ACE inhibitor group (1.8% vs. 2.0%; adjusted hazard ratio, 0.65; 95% CI, 0.30 to 1.38; P=0.65). In matched populations (803 pairs), the ARB group had a lower rate of cardiac death or MI than the no renin angiotensin system blocker group (1.7% vs. 3.1%; adjusted hazard ratio, 0.35; 95% CI, 0.14 to 0.90; P=0.03).

The authors noted that they did not have information on doses or duration of ACE inhibitors or ARBs, that the registry data they used were not randomized, and that the study was underpowered, among other limitations. However, they concluded that use of ARBs at discharge after STEMI in patients with preserved or slightly reduced systolic function yielded similar results to use of ACE inhibitors. They pointed out that although guidelines recommend consideration of ACE inhibitors for all patients without contraindications after STEMI, many patients cannot tolerate the drugs. “As the number of patients with preserved left ventricular systolic function is much greater than the number with depressed left ventricular systolic function after STEMI, the establishment of the role of angiotensin receptor blocker in patients with preserved left ventricular systolic function after STEMI is important,” the authors wrote.