Effects of empagliflozin on first and recurrent clinical events in patients with type 2 diabetes and atherosclerotic cardiovascular disease: a secondary analysis of the EMPA-REG OUTCOME trial

Background: Patients with type 2 diabetes and atherosclerotic cardiovascular disease are at high clinical risk. We assessed the effect of the sodium-glucose co-transporter-2 inhibitor, empagliflozin, on total cardiovascular events and admissions to hospital in the EMPA-REG OUTCOME trial. Methods: The EMPA-REG OUTCOME trial was a randomised, double-blind, non-inferiority trial of patients (aged ≥18 years) with type 2 diabetes and atherosclerotic cardiovascular disease done between August, 2010, and April, 2015. Participants were randomly assigned (1:1:1) to empagliflozin 10 mg or 25 mg, or placebo. The primary outcome was major adverse cardiovascular events: a composite of cardiovascular death, non-fatal stroke, or non-fatal myocardial infarction. As prespecified, the effects of pooled empagliflozin versus placebo were assessed on total (first plus recurrent) events of major adverse cardiovascular events, fatal or non-fatal myocardial infarction, fatal or non-fatal stroke, and admission to hospital for heart failure. We also did post-hoc analyses on additional cardiovascular and admission to hospital outcomes. We used statistical models that preserve randomisation and account for correlation of recurrent events, including negative binomial regression, as prespecified for the primary analyses. The EMPA-REG OUTCOME trial is registered with ClinicalTrials.gov, NCT01131676, and is closed to accrual. Findings: In the EMPA-REG OUTCOME trial, 7020 patients were randomly assigned and treated with empagliflozin 10 mg (n=2345), empagliflozin 25 mg (n=2342), or placebo (n=2333) and followed up for a median of 3·2 years (IQR 2·2 to 3·6) in the pooled empagliflozin group and 3·1 years (2·2 to 3·5) in the placebo group. Analysing total (first plus recurrent) events, empagliflozin versus placebo reduced the risk of major adverse cardiovascular events (rate ratio [RR] 0·78 [95% CI 0·67 to 0·91]; p=0·0020; 12·88 [95% CI 3·74 to 22·02] events prevented per 1000 patient-years); fatal or non-fatal myocardial infarction (0·79 [0·62 to 0·998]; p=0·049; 4·97 [–0·68 to 10·61] events prevented per 1000 patient-years); the composite of fatal or non-fatal myocardial infarction, or coronary revascularisation (0·80 [0·67 to 0·95]; p=0·012; 11·65 [1·25 to 22·05] events prevented per 1000 patient-years); admission to hospital for heart failure (0·58 [0·42 to 0·81]; p=0·0012; 9·67 [3·07 to 16·28] events prevented per 1000 patient-years); and all-cause admission to hospital (0·83 [0·76 to 0·91]; p<0·0001; 50·41 [26·20 to 74·63] events prevented per 1000 patient-years). For outcomes significantly reduced with empagliflozin, risk reductions were numerically larger for total events than for first events. Total fatal or non-fatal stroke was not significantly different between treatment groups (RR 1·10 [95% CI 0·82 to 1·49]; p=0·52). Interpretation: Empagliflozin reduced the total burden of cardiovascular complications and all-cause admission to hospital in patients with type 2 diabetes and atherosclerotic cardiovascular disease. Funding: The Boehringer Ingelheim and Lilly Alliance.