Clinical impacts of inhibition of renin–angiotensin system in patients with acute ST-segment elevation myocardial infarction who underwent successful late percutaneous coronary intervention

Background Successful percutaneous coronary intervention (PCI) of the occluded infarct-related artery (IRA) in latecomers may improve long-term survival mainly by reducing left ventricular remodeling. It is not clear whether inhibition of renin–angiotensin system (RAS) brings additional better clinical outcomes in this specific population subset. Methods Between January 2008 and June 2013, 669 latecomer patients with acute ST-segment elevation myocardial infarction (STEMI) (66.2 ± 12.1 years, 71.0% males) in Korea Acute Myocardial Infarction Registry (KAMIR) who underwent a successful PCI were enrolled. The study population underwent a successful PCI for a totally occluded IRA. They were divided into two groups according to whether they were prescribed RAS inhibitors at the time of discharge: group I (RAS inhibition, n = 556), and group II (no RAS inhibition, n = 113). Results During the one-year follow-up, major adverse cardiac events (MACE), which consist of cardiac death and myocardial infarction, occurred in 71 patients (10.6%). There were significantly reduced incidences of MACE in the group I (hazard ratio = 0.34, 95% confidence interval 0.199–0.588, p = 0.001). In subgroup analyses, RAS inhibition was beneficial in patients with male gender, history of hypertension or diabetes mellitus, and even in patients with left ventricular ejection fraction (LVEF) ≥40%. In the baseline and follow-up echocardiographic data, benefit in changes of LVEF and left ventricular end-systolic volume was noted in group I. Conclusions In latecomers with STEMI, RAS inhibition improved long-term clinical outcomes after a successful PCI, even in patients with low risk who had relatively preserved LVEF.