The ESC-invited discussant, Pascal Vranckx, MD, PhD, medical director, cardiac critical care services, Hartcentrum Hasselt, Belgium, liked the question being asked in the study, but concluded that the design was flawed.
“There are a variety of anticoagulants employed in a variety of doses [for PPA] but we have very limited data. The research question is totally appropriate,” he said. However, he asked, “What went wrong? Was it the drugs, the trial, or both?”
The problem, he thinks, is the dose. Much of the design of RIGHT was based on the 2015 MATRIX trial, which did show a benefit from a single dose of bivalirudin following PCI relative to two other comparators. In that study, STEMI patients randomized to bivalirudin received a bolus of 0.75 mg/kg followed by an infusion of 1.75 mg/kg per hour for at least 4 hours. The comparators were UFH or a control arm of low-molecular-weight heparin with optional glycoprotein IIb/IIIa inhibitors.
At 30 days, bivalirudin was associated with a 40% reduction (hazard ratio, 0.60; P = .001) relative to control for the composite primary endpoint of death or bleeding. Dr. Vranckx pointed out that MATRIX was a trial of a single-dose prolongation of PPA, whereas RIGHT was “a prolongation of a prolongation,” but he believes MATRIX data support higher doses of anticoagulation, particularly of bivalirudin.
“Perhaps low dose bivalirudin is not the way to go,” he speculated.
He further advised the authors to reevaluate the expected benefit from PPA following STEMI. In MATRIX, the risk for events was highly concentrated in the immediate period after PCI, suggesting that the opportunity to reduce risk is much lower as anticoagulation is prolonged. He suggested that the low number of events in RIGHT are consistent with the diminishing risk for events over time.
Nevertheless, Dr. Vranckx praised the authors for addressing a research question that is “timely and highly relevant.” He called the data “important” by drawing attention to a potential target for risk reduction, and encouraged additional trials to determine what PPA strategy, if any, can further reduce early ischemic events after PCI.
Dr. Yan and colleagues report financial relationships with Abbott, Boston Scientific, East China Pharmaceuticals, Saniju Medical and Pharmaceuticals, and Jiangsu Hengrui Pharmaceuticals, which provided funding for this study. Dr. Vranckx reports no potential conflicts of interest.
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