The timing of AVR for a 26-year man with aortic valve disease is determined by the patients symptoms and the function of the left ventricle (LV) which is the main pumping chamber of the heart. There are easy and reliable ways to estimate LV function. If your doctor has determined that the LV function of your fiance is such that he does not need AVR now, he may be right.
Marriage to a man with aortic valvular disease calls for full understanding on both sides. Physical
activity including sexual is permissible provided the LV function is good. Another point to bear in mind is that a man may need to take medications to prevent blood clotting on the valve after the operation. Nor can the possibility be ruled out that the valve may develop problems after many years and may need replacement again. Subject to these limitations, he can have a normal married life and employment.