Safety and Efficacy of Prolonged Use of Bivalirudin 4 Hours After ePCI (COBER Study)

Overview

Since the development of percutaneous coronary intervention (PCI) in patients with coronary heart disease (CHD), unfractionated heparin (UFH) and low molecular weight heparin (LWMH) have been the preferred anticoagulants in peri-operative period. However, UFH has some defects, such as incomplete and unstable inhibition of thrombin, large individual differences, multiple monitoring of activated coagulation time (ACT), ineffective thrombin binding to fibrin, non-specific protein binding and induced thrombocytopenia (HIT). Compared with UFH, LWMH has lower non-specific protein binding rate, but it is not superior to UFH in efficacy, hemorrhage and HIT. Bivalirudin can bind specifically to thrombin catalytic site and anionic external binding site, directly inhibit thrombin activity, thereby inhibiting thrombin-catalyzed and induced reactions. At the same time, thrombin can also inactivate it by enzymatic hydrolysis of bivalirudin. Therefore, the inhibition of bivalirudin on thrombin is reversible and transient, and the risk of bleeding after drug withdrawal is relative small. It has been reported that bivalirudin can significantly reduce the risk of peri-operative bleeding during PCI period compared with UFH. Clopidogrel had not yet played a role in most patients after emergency PCI, and there was a "blank period" for 2-4 hours without effective antithrombotic concentration, which was also the peak period of acute stent thrombosis. Han and coworkers have shown that for acute myocardial infarction (AMI) patients undergoing emergency PCI, whether or not glycoprotein IIb/IIIa inhibitors were added, prolonged peri-operative use of bivalrudin was significantly better than UFH in terms of net clinical adverse event. However, for patients with elective PCI (ePCI), prolonged bivalirudin use was only used in some patients in REPLACE-2 and ISAR-REACT-3 studies, and the prolonged time of bivalrudin use after ePCI was not definite. Therefore, in the current study we aim to explore the efficacy and safety of prolonged bivalirudin use 4 hours after elective PCI in patients with CHD.

The current study is designed as a single-center, randomized and prospective study aiming to evaluate the safety and efficacy of prolonged continuous use of bivalirudin 4 hours after ePCI for the treatment of peri-operative myocardial injury (PMI) compared with the bivalirudin use during ePCI. Based on previous study reported and estimated 10% loss follow-up of these patients in each arm, a total of 330 patients with CHD were required in our study, and with 165 patients per group as a ratio of 1:1 randomization.