Recurrent cardiovascular events in patients with newly diagnosed acute coronary syndrome: Influence of diabetes and its management with medication

Abstract Aims The effects of type 2 diabetes mellitus (T2DM) medications on secondary prevention after acute coronary syndrome (ACS) remain unclear. We evaluated recurrent cardiovascular disease (CVD) after primary diagnosis of ACS in T2DM patients. Methods This retrospective cohort study included 569 patients with newly diagnosed ACS from 2007 to 2012. The endpoint was recurrent CVD up to a five-year maximum follow-up until 2016. Kaplan–Meier analysis and Cox proportional hazard regressions were performed to examine the association between T2DM diagnosis, different antidiabetic drugs, and recurrent CVD. Results Among 569 patients, 198 had T2DM. The mean follow-up was 1540 (interquartile range, 864–2157) days. Patients with diabetes showed higher risk of recurrent cardiovascular event compared with those without (P = 0.004). Patients with diabetes treated with metformin (65 patients) showed longer event-free survival, compared with those on other antidiabetic medications (P = 0.005). Multivariable analysis confirmed a reduced risk of recurrent CVD associated with metformin (hazard ratio, 0.33; 95% confidence interval, 0.12–0.91), while lower hemoglobin A1c levels on admission were not associated with better CVD outcomes. Conclusions T2DM increases risk of recurrent CVD after first ACS episode regardless of glycemic control on admission, while use of metformin may reduce recurrence.