This has very little relationship to valvers. This has been known for years in the medical community. In the arteries that are narrowed the blood is under high stree and high shear forces. Under these conditions platelets start clot formation. Aspirin works better for this.
With artificial valves the shape is different from the natural valve. When the valve flaps it causes eddy currents in the blood. Under this stagnation condition, fibrin starts clots. Warfarin works better for this.
This has probably been known for 30 years but about every 6 months some reported learns this for the first time and treats it as is if it is the biggest news since the discovery of fire. Then I get dozens of e-mails from people who have their hopes falsely raised. Figure on taking warfarin for at least another 10 years. If they come up with something sooner, you will be pleasantly surprised and I will retire.
