Platelet responsiveness to in vitro aspirin is independent of COX-1 and COX-2 protein levels and polymorphisms.

Aspirin's inhibitory effect on platelet function has been shown to be highly heterogeneous. However, due to the considerable individual variation in pharmacokinetics after aspirin intake, it has been difficult to investigate the mechanism of aspirin resistance empirically. Our objective was to examine whether platelet responsiveness to in vitro aspirin treatment could be affected by cyclooxygenase (COX)-1/2 protein levels in platelets or single-nucleotide polymorphisms (SNPs), which could possibly change specific activity of enzymes and/or aspirin susceptibility.