Effect of empagliflozin on total myocardial infarction events by type and additional coronary outcomes: insights from the randomized EMPA-REG OUTCOME trial

Abstract

Background: The effect of empagliflozin, a sodium-glucose-co-transporter-2 inhibitor, on risk for myocardial infarction has not been fully characterized. Methods: This study comprised prespecified and post-hoc analyses of the EMPA-REG OUTCOME trial in which 7020 people with type 2 diabetes (T2D) and cardiovascular disease [mostly atherosclerotic (ASCVD)] were randomized to empagliflozin or placebo and followed for a median 3.1 years. We assessed the effect of empagliflozin on total (first plus recurrent) events of centrally adjudicated fatal and non-fatal myocardial infarction (MI) using a negative binomial model with robust confidence intervals (CI) that preserves randomization and accounts for the within-patient correlation of multiple events. Post hoc, we analyzed types of MI: type 1 (related to plaque-rupture/thrombus), type 2 (myocardial supply–demand imbalance), type 3 (sudden-death related, i.e. fatal MI), type 4 (percutaneous coronary intervention-related), and type 5 (coronary artery bypass graft-related). MIs could be assigned to > 1 type. Results: There were 421 total MIs (including recurrent); 299, 86, 26, 19, and 1 were classified as type 1, 2, 3, 4, and 5 events, respectively. Overall, empagliflozin reduced the risk of total MI events by 21% [rate ratio for empagliflozin vs. placebo, 0.79 (95% CI, 0.620–0.998), P = 0.0486], largely driven by its effect on type 1 [rate ratio, 0.79 (95% CI, 0.61–1.04)] and type 2 MIs [rate ratio, 0.67 (95% CI, 0.41–1.10)]. Conclusions: In T2D patients with ASCVD, empagliflozin reduced the risk of MIs, with consistent effects across the two most common etiologies, i.e. type 1 and 2. Trail Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01131676.