Some thoughts...
If there's calcification with the stenosis or regurgitation (and there very often is), that can definitely cause TIAs. This is mostly from tiny pieces of apatite crust breaking off and traveling through the bloodstream to the affected points. Episodes of that type of TIA should dissipate after surgery.
The use of coumadin (warfarin) is not such a simple decision, any more than creating the liability of certain reoperation should be.
As pointed out by abbanabba, coumadin can affect other health issues you have or may contract, or create difficulties with the treatments for them (not just getting teeth pulled).
It can increase the risks of subsequent operations of any type, and certainly complicates many otherwise routine medical and dental procedures, such as colonoscopy and root canal. Even bridging is not without its risks.
A small percentage of people have bad reactions (called adverse events) with coumadin, and it's not really a drug you want to go without, once you've got your valve. In some people (again, a small percentage), it seems to be very difficult to control dosage. In some instances, it can make users prone to other issues, such as Purple Toe Syndrome.
If you have a history of severe gastric issues involving stomach or intestinal bleeding, or any other continuing or recurring bleeding disorder, you should ask your doctor to consider this when determining whether you should be given a type of valve that requires ACT (Anti-Coagulation Therapy).
It's a drug that can have very desirable benefits, including reducing the risk of stroke for people with AFib or previous strokes, and allowing the reliable use of a usually permanent valve type that would otherwise be a stroke risk itself. The great majority of people adjust to it fairly well to extraordinarily well. But like all drugs, it's not without its drawbacks, and it's not universally well-tolerated among patients.
Best wishes,
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