Prevalence and predictors of dyspnea in acute coronary syndrome patients receiving ticagrelor: A prospective cohort study in Iran

The occurrence of dyspnea in patients with acute coronary syndrome (ACS) has always been considered a challenging diagnostic and therapeutic clinical scenario. Ticagrelor, a platelet receptor inhibitor, has beneficial effects in the prevention of ischemic events and mortality, but can cause dyspnea in ACS patients. In this study, we intend to investigate the prevalence of dyspnea in patients with ACS who are under treatment with ticagrelor. This prospective observational cohort study included 200 patients diagnosed with ACS from March 2020 to March 2022 and referred to the Cardiology Department of Modarres Hospital. After prescribing the medicine, the presence and severity of dyspnea were recorded daily according to the modified Borg dyspnea scale during hospitalization. Patients were followed up for 3 months after discharge, and the occurrence of dyspnea was investigated based on the characteristics of the patients. There were no major differences between groups in terms of gender, diabetes, hypertension, or smoking status. Most patients had normal lung auscultation, and the majority presented with unstable angina. Our results showed that 21.5% of patients experienced dyspnea, and 3% of patients stopped using drugs due to the severity of dyspnea. The time of the first attack varied from 1.5 to 36 hours after drug administration, and the maximum intensity of the first attack reached 7. The duration of the second attack varied from 2 to 22 days and was observed with a maximum intensity of 6. The age of patients was significantly higher in people who experienced dyspnea compared to those without dyspnea. Dyspnea is a common side effect in ACS patients receiving ticagrelor. The etiology of new-onset dyspnea in these patients can be complex and challenging to evaluate, as conventional factors did not appear to predict its occurrence. Given the significant therapeutic benefits of ticagrelor, discontinuation should only be considered for persistent and intolerable dyspnea associated with the medication. Further large-scale studies are warranted to better understand its clinical significance and to develop optimal management strategies.