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 beta-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 beta-blockers than in those not receiving beta-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 beta-blockers than in those not on beta-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 beta-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 beta-blocker treatment. Conclusions: In patients with diabetes and CHD, the use of beta-blockers was effective in reducing all-cause mortality in those with MI/HFrEF but not in those without MI/HFrEF.