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

BACKGROUND

The effects of β-blocker therapy in patients with type 2 diabetes (T2D) and established atherosclerotic cardiovascular disease (ASCVD) are unclear. We sought to evaluate associations between β-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 β-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 β-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 β-blocker use versus no β-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 β-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 β-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 β-blocker therapy in this patient population. (TECOS ClinicalTrials.gov number, NCT00790205).