I read your question carefully and I understand your concern. Regarding the question for the life span that depends by the risk of a stroke re-occurring, there s no more risk from the one he s recovered from. So since it depends from the risk of the stroke re-occurring that depends from what caused that stroke in the first place and if that cause has been removed. If the reason was for example with an arterial dissection causing the stroke then after treatment his life expectancy is the same as anyone s, same could apply to a heart defect which has been corrected. If on the other hand he suffers from let s say: mechanical valve in the heart, high blood pressure, diabetes, high cholesterol, smokes, is obese, leads a sedentary life and ignores the prescribed treatment then of course there s a high risk of him having another stroke. Of course this last one is an example, I don t imagine he has all of those factors. Even if he has some of them the main thing is to pay attention to adressing them and take the prescribed blood thinners, that will lower his risk dramatically and being young he can lead a long life. I hope everything works out for the best.