Impact of Pre-PCI Activated Clotting Time on Outcomes of Bivalirudin Versus Heparin During Primary PCI

The BRIGHT-4 trial demonstrated that procedural anticoagulation with bivalirudin followed by a median 3-hour high-dose infusion reduced the 30-day composite of all-cause mortality or Bleeding Academic Research Consortium (BARC) types 3 to 5 bleeding compared with heparin alone among patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention (PCI). Whether the pre-PCI activated clotting time (ACT) influences this benefit is unknown. In the study, we aim to investigate whether the pre-PCI ACT levels affected the outcomes with each anticoagulant.

The BRIGHT-4 protocol required a pre-PCI ACT to be assessed 5 minutes after study medications were administered with additional anticoagulant boluses given to achieve an ACT ≥225 seconds. In the present prespecified analysis, 30-day outcomes were analyzed according to the initial pre-PCI ACT level.

The initial pre-PCI ACT was <225 seconds in 971 of 5461 (17.8%) patients, including 123 of 2776 (4.4%) after bivalirudin and 848 of 2685 (31.6%) after heparin (P < .0001). Among 4490 of 5461 (82.2%) patients with an initial ACT ≥225 seconds, bivalirudin was associated with a lower incidence of BARC types 3 to 5 bleeding (0.2% vs 0.8%; adjusted hazard ratio, 0.22; 95% CI, 0.08-0.62; P = .004) and stent thrombosis (0.4% vs 1.0%; adjusted hazard ratio, 0.38; 95% CI, 0.18-0.81; P = .01) compared with heparin. Outcomes were not significantly different in bivalirudin and heparin-treated patients with an initial pre-PCI ACT <225 seconds. There were no significant interactions present between pre-PCI ACT strata and the treatment group for the primary end point or any of the secondary end points.

Among patients with ST-segment elevation myocardial infarction undergoing PCI with radial artery access, procedural anticoagulation with bivalirudin was associated with lower 30-day rates of mortality, BARC types 3 to 5 bleeding, and stent thrombosis compared with heparin, findings that were consistent regardless of the pre-PCI ACT level.