Abstract 4144749: Evolving Trends and Outcomes of P2Y12 Inhibitor Pretreatment in Non-ST-Elevation Acute Coronary Syndrome in the United States: Insights from the NCDR Chest Pain-MI Registry

Background: Although high rates of P2Y12 inhibitor pretreatment for non-ST-elevation acute coronary syndrome (NSTE-ACS) have been reported, contemporary practice pattern in the U.S. are not well studied. Objectives: To investigate the temporal trends, variability, and clinical outcomes of P2Y12 inhibitor pretreatment in NSTE-ACS across U.S. Methods: Consecutive patients that underwent early invasive strategy for NSTE-ACS (coronary angiogram ≤ 24 hours of arrival) in National Cardiovascular Data Registry (NCDR) Chest Pain-Myocardial Infarction (MI) registry was analyzed. Initially, a time-trend analysis was conducted on the complete cohort from January 1, 2013, to March 31, 2023. Subsequently, a more recent cohort (January 1, 2019, to March 31, 2023), with a complete set of variables, was used to construct a hierarchical regression model to quantify variability in the use of pretreatment among institutions and hospital regions. For this contemporary cohort, instrumental variable analysis was performed to compare in-hospital outcomes between patients who received pretreatment and those who did not. Results: Use of P2Y12 inhibitor pretreatment has decreased from 24.8% in 2013Q1 to 12.4% in 2023Q3. Among the contemporary cohort of 110,148 patients (2019-23; mean age, 63.9 [SD 12.5] years; 33.0% female), 17,509 (15.9%) received pretreatment. Significant variability in P2Y12 inhibitor pretreatment was observed (range: 0-100%): hierarchical regression model demonstrated that two identical patients would have more than a three-fold difference in the odds of pretreatment by changing institution or hospital region (OR 3.63; 95% CI, 3.51-3.74 and 3.21; 95% CI, 2.90-3.54, respectively). Instrumental variable analysis demonstrated no significant differences in in-hospital all-cause death (1.5% vs 1.7%; p=0.071), recurrent MI (0.56% vs 0.57%; p=0.98), or major bleeding (2.7% vs 2.8%; p=0.98) between the two groups. However, in patients who underwent coronary artery bypass surgery, pretreatment was associated with a longer length of stay (11.2 ± 5.1 days vs 9.8 ± 5.0 days; p < 0.001). Conclusions: Within the nationwide registry in the U.S., we observed a significant variability in the use of P2Y12 inhibitor pretreatment among NSTE-ACS patients in the U.S. Given the lack of clear advantages and the potential for prolonged hospital stays, our findings highlight the importance of efforts to improve standardization.