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 P2Y12 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 P2Y12 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 P2Y12 inhibitors. Among study patients, 32.9% received a precatheterization P2Y12 inhibitor (of these, 2.2% were given ticagrelor and 3.7% prasugrel). Time from catheterization to CABG was longer among patients who received precatheterization P2Y12 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 P2Y12 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 P2Y12 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 P2Y12 inhibitor use is associated with higher risks of postoperative bleeding and transfusion.