(P-401) Inpatient Readmission and Oral Antiplatelet Adherence for Patients with Coronary Artery Disease

Background: Acute cardiovascular syndrome (ACS) and medication non-adherence are two important contributing factors for the high readmission rates of patients with an acute myocardial infarction (AMI) discharge. Ticagrelor, clopidogrel, and prasugrel (TCP) are three of the most prescribed antiplatelet medications (APM) post-AMI.

Objectives: To compare ACS-related readmissions and medication adherence of patients with coronary artery disease taking ticagrelor, prasugrel or clopidogrel.

Methods: This was a retrospective observational study of patients with an index ACS-related hospitalization between July 1,2017 and December 31, 2018 who filled an APM post-discharge. Using integrated pharmacy and medical claims data from a large national pharmacy benefits manager for commercially insured adults aged ≥ 18 years, we assessed ACS-related readmission and medication adherence (as medication possession ratio [MPR]) associated with TCP utilization within 365 days of discharge. Using logistic regression controlling for age, gender, Charlson comorbidity index (CCI), days to first APM, MPR, and pre-study hospitalizations, we estimated the odds of readmission of the TCP cohorts.

Results: There were 948 eligible patients with continuous enrollment. Of these, 55% were on clopidogrel, 36% on ticagrelor and 9% on prasugrel. Patients in the ticagrelor group were younger (54.1 years [SD:8.9]), than the clopidogrel (55.8 years [SD: 9.8]) and prasugrel groups (55.9 years [SD:8.8]). There were 5.3%, 8.5%, and 4.7% readmissions in the TCP cohorts respectively. Additionally, there were statistically significant differences in CCI between clopidogrel (1.4) and ticagrelor (0.6) or prasugrel (0.7) cohorts. Similarly, MPR was highest in the ticagrelor (88.1%), followed by prasugrel (79.1%), and clopidogrel (76.4%) cohorts. There were no statistically significant differences in the odds of readmission among the cohorts [Clopidogrel: 1.01 (95% CI: 0.956-1.07), prasugrel: 0.96 (95% CI 0.85-1.10)] with ticagrelor as reference.

Conclusions: Although ticagrelor had the highest medication adherence, there were no statistically significant differences in odds of readmission among the three cohorts after controlling for covariates such as age, CCI, and adherence