Effects of β‐blockers on all‐cause mortality in patients with type 2 diabetes and coronary heart disease

AIMS To assess whether the use of beta-blockers influences mortality and the incidence of major cardiovascular events in patients with diabetes and coronary heart disease (CHD). MATERIALS AND METHODS Using data from the Bypass Angioplasty Revascularization Investigation 2 Diabetes trial, we performed Cox proportional hazards analysis to assess the effects of β-blockers on all-cause mortality in 2244 patients with type 2 diabetes who had stable CHD with and without a history of myocardial infarction (MI)/heart failure with reduced left ventricular ejection fraction (HFrEF). RESULTS All-cause mortality in patients with MI/HFrEF was significantly lower in those receiving β-blockers than in those not receiving β-blockers (adjusted hazard ratio [HR] 0.60, 95% confidence interval [CI] 0.37-0.98; P  = .04), whereas that in patients without MI/HFrEF did not significantly differ (adjusted HR 0.91, 95% CI 0.76-1.32; P  = .64). Among patients with MI/HFrEF, all-cause mortality in those who received intensive medical therapy alone for CHD was significantly lower in those on β-blockers than in those not on β-blockers (adjusted HR 0.45, 95% CI 0.23-0.88; P  = .02); however, mortality in patients who received early revascularization for CHD was not significantly lower in those on β-blockers (adjusted HR 0.81, 95% CI 0.40-1.65; P  = .57). The risk of major cardiovascular events in patients without MI/HFrEF was not significantly different between those on and those not on β-blocker treatment. CONCLUSIONS In patients with diabetes and CHD, the use of β-blockers was effective in reducing all-cause mortality in those with MI/HFrEF but not in those without MI/HFrEF.