Despite advanced techniques and improved clinical outcomes, the optimal antiplatelet strategy following
coronary artery bypass grafting (CABG) is an unsolved mystery.
Vorapaxar, a novel platelet
thrombin receptor (PAR-1/4) blocker, is currently approved for post-
myocardial infarction and
peripheral artery disease indications on top of
clopidogrel or/and
aspirin. We here summarize the outcomes in patients after CABG for justification of a future
vorapaxar trial. We comprehended the CABG outcomes after
vorapaxar yielded from TRACER, TRA2P trials, and affiliated FDA reviews. The verified evidence suggests that composite of death,
myocardial infarction and
stroke occurred in 2.2% of
vorapaxar vs. 8.1% placebo in TRA2P. These data were similar to the endpoint differences (5.9% after
vorapaxar vs. 8.3% for placebo) in TRACER. The mortality reduction also consistently suggests
vorapaxar advantage (1.7% vs. 2.5% in TRA2P, and 1.7% vs. 3.9% in TRACER). Notably, the post-CABG
bleeding risks after
vorapaxar were only slightly, but not significantly higher. Moreover, the
bleeding disadvantage in the experimental arm was most likely related to overtreatment since majority of patients in both TRACER and TRA2P received triple antiplatelet
therapy with
aspirin,
clopidogrel on top of
vorapaxar. Overall, the FDA-confirmed evidence advocate for the future
vorapaxar post-CABG outcome-driven trial. The head-to-head trial testing dual
therapy with continued over CABG
vorapaxar versus withdrawed
clopidogrel, both on top of low dose
aspirin is warranted. We conclude that the primary outcomes including mortality were consistently better for heart surgery patients after
vorapaxar, while the excess of
bleeding was mild. Continuing
vorapaxar during CABG may be superior to currently recommended withdrawal antiplatelet strategies, and should be tested in an adequately powered randomized outcome-driven trial.