Cardiovascular safety of tiotropium Respimat vs HandiHaler in the routine clinical practice: A population-based cohort study

The cardiovascular safety of tiotropium Respimat formulation in the routine clinical practice is still an open issue. Our aim was to compare the risk of acute myocardial infarction and heart rhythm disorders in incident users of either tiotropium Respimat or HandiHaler. The study population comprises patients aged ≥45 years, resident in two Italian regions with a first prescription of tiotropium (HandiHaler or Respimat) between 01/07/2011-30/11/2013. The cohort was identified through the database of prescriptions reimbursed by the Italian National Health Service. Comorbidities and clinical outcomes were obtained from hospital records. The primary outcome was the first hospitalization for acute myocardial infarction and/or for heart rhythm disorders during the exposure period. Hazard ratios were estimated in the propensity score-matched groups through Cox regression. After matching, 31,334 patients with incident prescription of tiotropium were included. The two groups were balanced with regard to baseline characteristics. Similar incidence rates of the primary outcome between Respimat and HandiHaler users were identified (adjusted hazard ratio 1.02, 95% CI 0.82-1.28). No risk difference between Respimat and HandiHaler emerged when considering clinical events separately. This large cohort study showed a comparable acute cardiovascular safety profile of the two tiotropium formulations.