Relationship of inhaled long-acting bronchodilators with cardiovascular outcomes among patients with stable COPD: a meta-analysis and systematic review of 43 randomized trials

Background: Long-acting muscarinic antagonists (LAMAs) and long-acting beta 2-agonists (LABAs) are the mainstay of maintenance therapy for chronic obstructive pulmonary disease (COPD). Although previous studies have supported inhaled long-acting bronchodilators (ILABs) for overall cardiovascular safety, the risk of specific cardiovascular outcomes such as arrhythmia, heart failure and stroke is still unknown. Materials and methods: We systematically searched from PubMed, the Embase database and the Cochrane Library for published studies on ILABs and COPD, from its inception to November 10, 2018, with no language restrictions. The RRs and corresponding 95% CIs were pooled to evaluate ILAB/placebo. Results: Finally, 43 randomized controlled trials were included. Compared with placebo, ILABs do not increase the risk of overall and specific cardiovascular adverse events (AEs); on the contrary, they can reduce the incidence of hypertension (RR 0.73, 95% CI 0.55-0.98; I219.9%; P=0.221). However, when stratified according to the specific agents of ILABs, olodaterol might reduce the risk of overall cardiovascular adverse events (OCAEs) (RR 0.65, 95% CI 0.49-0.88; I(2)27.5%; P=0.000), and the protective effect of lowing blood pressure disappeared. Similarly, the use of inhaled LABA might increase the risk of cardiac failure (RR 1.71, 95% CI 1.04-2.84; I(2)0%; P=0.538), but this risk disappeared when stratified according to the specific agents of LABA. Besides, formoterol might decrease the risk of cardiac ischemia (RR 0.53, 95% CI 0.32-0.91; I(2)0%; P=0.676). Conclusions: Overall, the use of ILABs was not associated with overall cardiovascular AEs in patients with stable COPD. When stratified according to the specific agents of LABA, olodaterol might reduce the risk of OCAE; and formoterol might decrease the risk of cardiac ischemia. LABA might reduce the incidence of hypertension, but might increase the risk of heart failure. Therefore, COPD patients with a history of heart failure should use it with caution.