Bisoprolol for patients with chronic obstructive pulmonary disease at high risk of exacerbation: the BICS RCT

Background: Observational studies of people with chronic obstructive pulmonary disease using beta-blockers for cardiovascular disease indicate that beta-blocker use is associated with reduced risk of chronic obstructive pulmonary disease exacerbation. However, at the time this study was initiated, there had been no randomised controlled trials confirming or refuting this. Objective(s): To determine the clinical and cost-effectiveness of adding bisoprolol (maximal dose 5 mg once daily) to usual chronic obstructive pulmonary disease therapies in patients with chronic obstructive pulmonary disease at high risk of exacerbation. Design: A multicentre, pragmatic, double-blind, randomised, placebo-controlled clinical trial. Setting: Seventy-six United Kingdom primary and secondary care sites. Participants: People aged ≥ 40 years with a diagnosis of at least moderately severe chronic obstructive pulmonary disease with a history of at least two exacerbations in the previous year. Interventions: Participants were randomised (1: 1) to receive either bisoprolol or placebo for 1 year. During a 4-to 7-week titration period, the maximum tolerated dose was established (1.25 mg, 2.5 mg, 3.75 mg, 5 mg once daily). Primary outcome: A number of participant-reported exacerbations during the 1-year treatment period. Results: In total, 519 participants were recruited and randomised. Four post-randomisation exclusions left 259 in the bisoprolol group and 256 in the placebo group. Treatment groups were balanced at baseline: mean (standard deviation) age 68 (7.9) years; 53% men; mean (standard deviation) pack year smoking history 45 (25.2); mean (standard deviation) 3.5 (1.9) exacerbations in previous year. Primary outcome data were available for 99.8% of participants (bisoprolol 259, placebo 255). The mean (standard deviation) number of exacerbations was 2.03 (1.91) in the bisoprolol group and 2.01 (1.75) in the placebo group (adjusted incidence rate ratio 0.97, 95% confidence interval 0.84 to 1.13), p = 0.72. The number of participants with serious adverse events was similar between the two groups (bisoprolol 37, placebo 36). The total number of adverse reactions was also similar between the two groups. As expected, bisoprolol was associated with a higher proportion of vascular adverse reactions (e.g. hypotension, cold peripheries) than placebo, but was not associated with an excess of other adverse reactions, including those classified as respiratory. Adding bisoprolol resulted in a statistically insignificant trend towards higher costs (£636, 95% confidence interval £118 to £1391) and fewer quality-adjusted life-years (0.035, 95% confidence interval 0.059 to 0.010) compared to placebo. Limitations: The study findings should be interpreted with caution as the target sample size of 1574 was not achieved because the funder considered the study to be unviable in the COVID-19 pandemic clinical research environment. Although 28% of participants did not initiate bisoprolol/placebo (1.6%) or ceased during the treatment period (26.2%), this is consistent with similar trials in the United Kingdom. Conclusions: In this underpowered study, the addition of bisoprolol to usual chronic obstructive pulmonary disease treatment did not reduce the likelihood of exacerbations, and bisoprolol cannot be recommended as a treatment for chronic obstructive pulmonary disease. Future work: To incorporate definitive statements into appropriate clinical guidelines about the safety of bisoprolol for cardiovascular indications in people with chronic obstructive pulmonary disease.