Ticagrelor-related late-onset dyspnea as cause of emergency department visit: a 3-year outpatient study.

Introduction: The aim of the current study was to define the rate of emergency department visits for late-onset dyspnea in acute coronary syndrome patients treated with ticagrelor.

Methods: We conducted a population-based study on about 850 000 residents of Florence metropolitan area, by using data from healthcare records.

Results: Between 2012 and 2014, 1073 subjects in Florence metropolitan area had at least one prescription of ticagrelor. Two-hundred and thirty-four patients were diagnosed with 'respiratory system or other chest symptoms' or 'other diseases of lung', and among them we identified 20 subjects with ticagrelor-related late-onset dyspnea. These, and the 979 nonevent subjects (receiving ticagrelor but not developing dyspnea), contributed to 413 person-years overall. The dyspnea rate was 4.84 per 100 person-years (95% confidence interval: 3.12-7.51).

Conclusion: Late-onset dyspnea rate is notably lower than early-onset one; nevertheless prescribing clinicians should be aware that about one in 20 outpatients with a stabilized ticagrelor treatment might develop a dyspnea leading to an emergency department visit, and they should consider ticagrelor replacement only in patients who cannot tolerate dyspnea.