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I am Dr. Sohaib, a Medical Internist (who deals with diseases of all the organ systems of body) and i will do my best to find an answer for you.
At your age, the preferred choice should be a biological valve.
Although the mechanical valves last longer but they are usually preferred for younger patients. This is because with mechanical valves one has to take blood thinners like coumadin, and with advancing age the chances of side effects of these medications are much higher.
With biological valve, you would not require blood thinners, and these days the available biological valves have a reasonably good life lasting over 10 years.
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