Precatheterization Use of P2Y 12 Inhibitors in Non‐ST‐Elevation Myocardial Infarction Patients Undergoing Early Cardiac Catheterization and In‐Hospital Coronary Artery Bypass Grafting: Insights From the National Cardiovascular Data Registry ®

Background Current guidelines recommend early P2Y 12 inhibitor administration in non‐ ST ‐elevation myocardial infarction, but it is unclear if precatheterization use is associated with longer delays to coronary artery bypass grafting ( CABG ) or higher risk of post‐ CABG bleeding and transfusion. This study examines the patterns and outcomes of precatheterization P2Y 12 inhibitor use in non‐ ST ‐elevation myocardial infarction patients who undergo CABG . Methods and Results Retrospective analysis was done of 20 304 non‐ ST ‐elevation myocardial infarction patients in the ACTION (Acute Coronary Treatment and Intervention Outcomes Network) Registry (2009–2014) who underwent catheterization within 24 hours of admission and CABG during the index hospitalization. Using inverse probability‐weighted propensity adjustment, we compared time from catheterization to CABG , post‐ CABG bleeding, and transfusion rates between patients who did and did not receive precatheterization P2Y 12 inhibitors. Among study patients, 32.9% received a precatheterization P2Y 12 inhibitor (of these, 2.2% were given ticagrelor and 3.7% prasugrel). Time from catheterization to CABG was longer among patients who received precatheterization P2Y 12 inhibitor (median 69.9 hours [25th, 75th percentiles 28.2, 115.8] versus 43.5 hours [21.0, 71.8], P <0.0001), longer for patients treated with prasugrel (median 114.4 hours [66.5, 155.5]) or ticagrelor (90.4 hours [48.7, 124.5]) compared with clopidogrel (69.3 [27.5, 114.6], P <0.0001). Precatheterization P2Y 12 inhibitor use was associated with a higher risk of post‐ CABG major bleeding (75.7% versus 73.4%, adjusted odds ratio 1.33, 95% confidence interval 1.22‐1.45, P <0.0001) and transfusion (47.6% versus 35.7%, adjusted odds ratio 1.51, 95% confidence interval 1.41‐1.62, P <0001); these relationships did not differ among patients treated with clopidogrel, prasugrel, or ticagrelor. Conclusions Precatheterization P2Y 12 inhibitor use occurs commonly among non‐ ST ‐elevation myocardial infarction patients who undergo early catheterization and in‐hospital CABG . Despite longer delays to surgery, the majority of pretreated patients proceed to CABG <3 days postcatheterization. Precatheterization P2Y 12 inhibitor use is associated with higher risks of postoperative bleeding and transfusion.