Editorial commentary: Cardiac MRI imaging in heart failure with preserved ejection fraction.

Beta-blockers (βB) are a frequently used class of medications. Although βB have many indications, those related to cardiovascular disease are among the most common and important. However, in patients with chronic obstructive pulmonary disease (COPD), βB are used less often due to concerns about an unfavorable impact on respiratory morbidity and mortality. We performed a systematic review to assess the safety of βB in patients with COPD. We included a total of 2 randomized controlled trials and 28 observational studies. The majority found statistically significant reductions in mortality. The two higher quality observational studies reported increased mortality with βB. The risk of COPD exacerbations was reduced in about half of the studies. Nonetheless, there were significant biases that confounded the results. The highest quality RCT found a significant increase in severe and very severe COPD exacerbations with βB use. In conclusion, data on the safety of βB in patients with COPD are conflicting. However, given higher quality evidence showed harm with their use, βB should be prescribed with caution in patients with COPD, including patients with cardiac indication for βB.