Associations between β-blocker therapy and cardiovascular outcomes in patients with diabetes and established cardiovascular disease

Background The effects of beta-blocker therapy in patients with type 2 diabetes (T2D) and established atherosclerotic cardiovascular disease (ASCVD) are unclear. We sought to evaluate associations between beta-blocker use in T2D with ASCVD and cardiovascular (CV) outcomes. Methods In patients with T2D and ASCVD enrolled in the Trial Evaluating Cardiovascular Outcomes with Sitagliptin (TECOS), an inverse probability of treatment-weighted Cox proportional hazards model was used to examine the association between baseline beta-blocker therapy (at randomization) and the primary CV composite (defined as CV death, non-fatal myocardial infarction [MI], non-fatal stroke, or hospitalization for unstable angina), including in subgroups with prior MI and heart failure (HF); other outcomes evaluated included individual components of the primary composite, hospitalization for HF, and severe hypoglycemic events. Results Of the 14,671 patients randomized, 9322 (64%) were on a beta-blocker at baseline; these patients were more likely to have prior MI or HF. Over a median 3.0 (25th, 75th percentile: 2.2, 3.6) years, the risk of the primary CV composite was significantly higher with baseline beta-blocker use versus no beta-blocker use (4.5 vs. 3.4 events/100-patient years, adjusted hazard ratio [HR] 1.17, 95% confidence interval [CI] 1.05-1.29); no significant interaction was noted for patients with versus without prior MI or HF. Baseline beta-blocker use was not associated with risks for severe hypoglycemic events (HR 1.14, 95% CI 0.88-1.48). Conclusions In this observational analysis of T2D and ASCVD, baseline beta-blocker use was not associated with risks for severe hypoglycemia yet also was not associated with CV risk reduction over 3 years of follow-up, supporting a randomized examination of chronic beta-blocker therapy in this patient population.