OBJECTIVES: Oral antiplatelet agent (OAA) is a medication class that reduces complications after the onset of acute coronary syndrome (ACS). The addition of 3rd-generation OAAs (3G-OAA: prasugrel and ticagrelor) on top of the historic standard strategy, clopidogrel, has enabled physicians to contemplate switching among therapies for specific clinical and financial circumstances. This study aimed to describe the persistence on and switching from the initially prescribed OAA after the onset of ACS.

METHODS: This was a retrospective analysis of standardized healthcare records from nine healthcare systems participating in the Greater Plains Research Collaboratives. Patients included in this study were hospitalized with a diagnosis of ACS between July 2009 and June 2019. The analytic cohort included patients who had a prescription record for one of the three OAAs within seven days of the ACS discharge. OAA switching over the 180 days from the initial OAA prescription was classified into three categories, escalation (switching from clopidogrel to 3G-OAA), de-escalation (switching from 3G-OAA to clopidogrel), and conversion (switching between the two 3G-OAAs).

RESULTS: A total of 12,929 patients receiving an OAA for ASC were identified. Clopidogrel dominated the initial OAA prescription with 81% (n=10,497) of the identified patients receiving clopidogrel as a first-line option. A 43% of the initial 3G-OAA prescription switched to an alternative before the end of the 180-day follow-up. Of the patients who switched their OAA, the respective proportions of the escalation, d-escalation, and conversion were 29%, 68%, and 3%.

CONCLUSION: Despite the superior efficacy of 3G-OAAs from clinical trial data, clopidogrel remained the preferred choice over the last decade. A substantial proportion of patients de-escalated their OAA strategy. Further investigation into the reasons for the premature discontinuation of 3G-OAA is warranted.