Abstract 318: Risk of Cardiovascular and Major Bleeding Event Rehospitalizations and Cost of Care Among ACS Patients in the US
Authors: Stellhorn Robert , Ciniglio Cathleen , Sengupta Nishan 
Published: March 2022

OBJECTIVE:
To determine the risk of cardiovascular (CV) and major bleeding event rehospitalizations, as well as the cost of care among patients with an index Acute Coronary Syndrome (ACS) event and who are taking clopidogrel (C) compliantly (C-compliant; ≥0.80 proportion of days covered); non-compliantly (C-non-compliant); or receiving no antiplatelet (AP) or no anticoagulant (AC) (no-AP/AC) agents.

METHODS:
Patients with an ACS hospitalization between January 2008 and September 2009 and at least 1 year of follow-up were selected from the IMS Lifelink Health Plans Claims database. Cohorts were formed based on the initial AP (mainly C) or AC agent received within 7 days of post-ACS hospital discharge; aspirin data were not available. Rates and costs for rehospitalizations in follow-up for myocardial infarction (MI), ACS, ischemic heart disease (IHD; ICD-9-CM codes 410-414), and major bleeding (defined by ICD-9-CM codes) were determined.

RESULTS:
Among the 25,588 ACS patients, mean age was 62.6 years, 67.3% were male, and the occurrence of ST-elevation MI (STEMI), non-ST-elevation MI, and unstable angina was 39.0%, 52.0%, and 9%, respectively, during the index hospitalization period. Patients had other comorbidities, including diabetes (31.6%), hypertension (68.8%), and prior ACS event (24.9%). More than half the patients (n=14,682; 57.4%) initially received C, whereas 36.1% of patients did not receive any AP or AC during follow-up. Nearly all (99.4%) patients were taking at least 1 drug from the following 4 CV drug classes: HMG-coA reductase inhibitors, angiotensin-converting enzyme inhibitors, beta blockers, and calcium channel blockers; 10.34% of patients were taking agents from all 4 of these classes concurrently at any given time during follow-up. Of the C users, 55.7% were compliant based on 1-year follow-up (post-ACS hospital discharge). C-compliant patients had more STEMI (51.4% vs 45.9%;
P
<0.001) and percutaneous coronary intervention (PCI) (82.9% vs 68.8%;
P
<0.001) than C-non-compliant patients. No-AP/AC patients had the lowest STEMI rate (31.3%) and the lowest PCI during the index hospitalization period (33.6%; both
P
<0.001 vs either C group). In the first year after index-event, C-compliant patients were readmitted less frequently for MI (2.6% vs 3.9%), ACS (3.0% vs 4.4%), IHD (12.8% vs 14.6%), and major bleeding (0.5% vs 1.0%; all
P
<0.010). During 1-year follow-up, per-member per-month costs for IHD readmissions were lower for C-compliant ($2,139) and no-AP/AC ($2,305) vs C-non-compliant patients ($2,714;
P
<0.001). Major bleeding readmission costs were $1,101-$1,573 for the 3 groups.

CONCLUSIONS:
CV-related rehospitalizations for ACS were lower in clopidogrel compliant patients. However, readmission rates and costs attributable to CV causes were still high, whereas those due to major bleeding were relatively low for all ACS patients in this study cohort. Compliance with multiple CV medications post-ACS hospital discharge may also improve CV outcomes.