Abstract 165: Evaluating the Relative Effectiveness of Reduced‐Dose Ticagrelor, Full‐Dose Ticagrelor, and Clopidogrel in Acute Stroke Management: Comparisons in an Observational Setting

Introduction The use of ticagrelor in the management of acute stroke is becoming a more common practice, however, the appropriate dosing regimen has not been extensively studied. Further, the effectiveness of ticagrelor relative to clopidogrel has not been extensively studied in observational settings. This study evaluates two different dosing strategies of ticagrelor compared to the standard practice clopidogrel dosing and associated outcomes. Methods We completed a retrospective chart review of patients diagnosed with acute ischemic stroke at a large academic comprehensive stroke center from September 1, 2020, to July 1, 2022. Three separate anti‐platelet groups (i.e. treatment groups) were created, low‐dose ticagrelor (45 mg or 60 mg twice a day), full‐dose ticagrelor (90 mg twice a day), and clopidogrel (75 mg daily). We collected and compared baseline demographic (age, sex, and race) and clinical (mrS and NIHSS at baseline, CT/MRI initial results, relevant medication history, and the Elixhauser index score based on comorbidities) characteristics. We used a Lasso model to select those sufficiently associated to a treatment. Then, we include the selected covariates to estimate a propensity score for each binary treatment (1. any ticagrelor vs. clopidogrel and 2. low‐dose vs. full‐dose ticagrelor) and balance the corresponding analytic samples via inverse propensity score weighting (IPW) to more appropriately assess and compare outcome measures: in‐hospital mortality, 90‐day mortality, functional independence defined as modified Rankin Score (mRS) of 0‐2, at discharge and 90 days, treatment groups. All data was analyzed using R software, version 4.3.2. Results A total of 363 patients were included in our study. The mean age was 66.1 ± 12.7 years and most patients were male (51.7%). The most common ethnicity was African American (83.9%). Fifty‐eight patients were discharged on low‐dose ticagrelor, 37 on full‐dose ticagrelor, and 342 on clopidogrel. Having adjusted for selected baseline demographic and clinical baseline characteristics, mortality at 90 days was found to be lower for patients prescribed with any ticagrelor versus those prescribed with clopidogrel (OR [95%CI]: 0.51 [0.28, 0.93]), while there was no significant difference in functional independence at 90 days between both groups. There was no statistical difference in terms of mortality or functional independence at 90 days between patients with low versus high ticagrelor dosage. Conclusion After appropriate adjustment of baseline factors, our study demonstrates a benefit for the use of any dose of ticagrelor over clopidogrel in long‐term outcomes, but also establishes no significant difference in outcome between a lower dose of ticagrelor.