Because the Ross Procedure rebuilds the heart with all human valve components, there is no need for any blood thinners even at the beginning. The body does not form clots on these valves so the risk of embolism is virtually zero. (There are other sources of embolic phenomena in the heart, aorta, carotid arteries and other blood vessels, but these are very uncommon in the young people who are candidates for the Ross.)
The advantage of avoiding blood thinners is enormous. The primary function of Coumadin is to prevent clots and it does so by slowing down the body’s clotting mechanism. It competes with Vitamin K in the manufacturing process of certain clotting factors. The effect of this “blood thinning” is measured by the prothrombin time which is now expressed as an INR or International Normalized Ratio of patient vs. control. Unfortunately, there are a host of medicines and many foods which conflict with this Vitamin K-dependent pathway and can lead to overly high or low effects. High INR (>4.0) is associated with a major risk of bleeding. Unfortunately, at least 30% of bleeding occurs in the central nervous system causing a stroke that can be disabling or fatal.
Patients on Coumadin must have regular blood tests to follow the INR and make appropriate adjustments in the dose of Coumadin. This can be a real problem if traveling to remote parts of the world. Activities which place one at risk of injury (particular head trauma) are particularly dangerous to people on Coumadin because once bleeding starts, it is harder to stop. Even in the somewhat elective circumstances of surgery that might be required such as hysterectomy or gall bladder removal, careful attention must be paid to balancing the risk of clotting against the risk of bleeding when temporarily stopping Coumadin.
With the Ross Procedure, Coumadin is simply not an issue.