Effects of long-acting bronchodilators on cardiac autonomic control in COPD

Several studies in COPD have shown a significant and early increase in the risk of cardiovascular mortality attributable to inhaled bronchodilators including long acting β2 agonists (LABAs) and muscarinic antagonists (LAMAs). Cardiac autonomic system impairment may be a potential mechanism involved.

We performed a phase 4, investigator-initiated, prospective, randomized, blinded, cross-over trial (LAB-Card trial - NCT02872090) to evaluate the effect of two LAMAs and one LABA on the cardiac autonomic system in patients with COPD by using three major assessment approaches: heart rate variability (HRV, a predictor of cardiovascular death), baroreflex sensitivity (BRS) and autonomic function (tilt test).

34 patients attended four visits to receive either tiotropium 18µg, glycopyrronium 44µg, indacaterol 150 µg or placebo (lactose) in a randomized order followed by the assessment of HRV and BRS in supine position and after passive rising. Neither LAMAs (tiotropium or glycopyrronium) nor LABA (indacaterol) induced a higher LF/HF ratio (reflect of sympathetic/parasympathetic balance) measured in supine position at rest compared to placebo (primary outcome). Solely indacaterol induced an increase in heart rate compared to placebo. No significant differences were observed for HRV and BRS between active drugs and placebo in supine position or after passive rising.

We did not found evidence of a deleterious effect of 2 LAMAs and one LABA on the autonomic cardiovascular control in COPD patients. Further investigations are needed to explore mechanisms by which long-acting bronchodilators may increase cardiovascular events in COPD.