American Board of Internal Medicine (ABIM) Certification Practice Exam

Which β-blockers have been shown to be beneficial in patients with heart failure with reduced ejection fraction (HFrEF)?

1. Atenolol and propranolol

2. Metoprolol succinate, carvedilol, and bisoprolol

3. Bisoprolol and nebivolol

4. Propranolol and carvedilol

The correct answer is: Metoprolol succinate, carvedilol, and bisoprolol

The information regarding the beneficial effects of specific β-blockers in patients with heart failure with reduced ejection fraction (HFrEF) is well-established in clinical practice. Metoprolol succinate, carvedilol, and bisoprolol have all been shown through large-scale clinical trials to improve outcomes in this patient population. These β-blockers work primarily by reducing myocardial oxygen demand, slowing heart rate, and providing a neurohormonal modulation that counteracts the detrimental effects of excessive sympathetic stimulation seen in heart failure. In particular, metoprolol succinate has demonstrated reductions in mortality and hospitalization rates in HFrEF patients. Similarly, carvedilol—not only a β-blocker but also an α-blocker—has shown efficacy in improving left ventricular function and overall survival. Bisoprolol, with its specific β1-selective blocking properties, has also been validated in studies like the CIBIS trial as beneficial for patients with HFrEF. Other mentioned β-blockers like atenolol and propranolol, while they have uses in various cardiovascular conditions, do not have the same level of evidence supporting their routine long-term use in HFrEF. Moreover, nebivolol, while a newer agent that has