FXa inhibitor blocks coagulation-induced GPVI shedding. Coagulation in citrated PRP induced by recalcification in the absence or presence of 0.2 U/mL enoxaparin (FXa and thrombin inhibitor), 1.25μM dabigatran (selective thrombin inhibitor), or 1 μg/mL rivaroxaban (selective FXa inhibitor). Thrombin generation assessed by the calibrated automated thrombin assay (A) was completely blocked by all inhibitors, whereas coagulation-induced sGPVI generation measured by ELISA (B) was blocked completely by rivaroxaban and enoxaparin, but only marginally attenuated by thrombin inhibitor, dabigatran.