Hi. Assuming they don't manage to find some underlying cause for this, structural defect that becomes more problematic as your heart ages, a disease of some kind (or the aftereffects of a viral infection, say COVID or gum health related...), then it might be an inherited defect, something related to genes. Whatever it turns out to be, the cardiologist has all the numbers of your blood circulation and overall health, and he/she isn't concerned for you. It's still early enough that you can monitor/be monitored as he/she suggests for the rate of deterioration, or maybe it will be largely stable....so why intervene and incur all the risks associated with surgery? So, it really is a numbers game: your risk of advanced heart deterioration versus the risk of surgery, while your blood oxygen and other indicators of health look really good, and so the risk of surgery trumps the risk of letting 'er ride for now. That's it...it's really that simple.

By now you know that a mitral valve can be replaced or repaired, or 'shored up' with an implant to help it do a better job for many more years. That's always the option, but a responsible physician will want you to agree to wait until the burden and risk become greater than the risk of what 'might happen' if they enter your heart and fix the valve.