In recent decades, important gains have been made in the treatment of chronic heart failure with reduced ejection fraction.1 β blockers are a cornerstone of the medical management of heart failure. The long term use of certain β blockers in patients with heart failure reduces hospital admissions and improves symptoms, quality of life, and survival. However, it is still unclear whether this is a class effect or whether one β blocker is superior to another. In a linked paper (doi:10.1136/bmj.f55), Chatterjee and colleagues conducted a network meta-analysis of trials to clarify the mortality benefits and tolerability of different β blockers in the treatment of patients with heart failure.2

Three landmark placebo-controlled trials of nearly 9000 patients with heart failure demonstrated the efficacy of carvedilol, long acting metoprolol succinate, and bisoprolol in reducing mortality and hospital admission in patients with heart failure.1 However, large trials of nebivolol and bucindolol found no reductions in all cause mortality compared with placebo, despite benefits in cardiovascular morbidity or mortality.3 4 Taken together, these data …