Mortality Reduction Associated With β-Adrenoceptor Inhibition in Chronic Heart Failure Is Greater in Patients With Diabetes

Diabetes increases mortality in patients with chronic heart failure (CHF) and reduced left ventricular ejection fraction. Studies have questioned the safety of β-adrenoceptor blockers (β-blockers) in some patients with diabetes and reduced left ventricular ejection fraction. We examined whether β-blockers and ACE inhibitors (ACEIs) are associated with differential effects on mortality in CHF patients with and without diabetes. We conducted a prospective cohort study of 1,797 patients with CHF recruited between 2006 and 2014, with mean follow-up of 4 years. β-Blocker dose was expressed as the equivalent dose of bisoprolol (mg/day) and ACEI dose as the equivalent dose of ramipril (mg/day). Cox regression analysis was used to examine the interaction between diabetes and drug dose on all-cause mortality. Patients with diabetes were prescribed larger doses of β-blockers and ACEIs than were patients without diabetes. Increasing β-blocker dose was associated with lower mortality in patients with diabetes (8.9% per mg/day; 95% CI 5-12.6) and without diabetes (3.5% per mg/day; 95% CI 0.7-6.3), although the effect was larger in people with diabetes (interaction = 0.027). Increasing ACEI dose was associated with lower mortality in patients with diabetes (5.9% per mg/day; 95% CI 2.5-9.2) and without diabetes (5.1% per mg/day; 95% CI 2.6-7.6), with similar effect size in these groups (interaction = 0.76). Increasing β-blocker dose is associated with a greater prognostic advantage in CHF patients with diabetes than in CHF patients without diabetes.