Use of ticagrelor and the risks of pneumonia and pneumonia-specific death in patients with non-acute coronary syndrome conditions: a population-based cohort study

Previous studies have shown that ticagrelor reduced risk of pneumonia in patients with acute coronary syndrome (ACS) compared to clopidogrel, however, its effect in patients with non-ACS cardiovascular diseases remains uncertain. The aim was to investigate the effect of ticagrelor on pneumonia and pneumonia-specific death compared to clopidogrel in non-ACS patients in Hong Kong. This was a population-based cohort study. We included consecutive patients using ticagrelor or clopidogrel admitted for non-ACS conditions in Hong Kong public hospitals from March 2012 to September 2019. Patients using both drugs were excluded. The outcomes of interest were incident pneumonia, all-cause death, and pneumonia-specific death. Multivariable survival analysis models were used to estimate the effects [hazard ratio (HR) and 95% confidence interval (CI)]. Propensity score matching, adjustment and weighting were performed as sensitivity analyses. In total, 90,154 patients were included (mean age 70.66 years, males 61.7%). The majority of them (97.2%) used clopidogrel. Ticagrelor was associated with a lower risk of incident pneumonia [0.59 (0.46–0.75)], all-cause death [0.83 (0.73–0.93)] and pneumonia-specific death [0.49 (0.36–0.67)]. Sensitivity analyses yielded similar results. Ticagrelor was associated with lower risk of all-cause death, pneumonia-specific death, and incident pneumonia in patients with non-ACS cardiovascular conditions, consistent with previous evidence in patients with ACS. This additional effect of anti-pneumonia should be considered when choosing a proper P2Y12 inhibitor for patients with high risk of pneumonia.