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.