Dads heart function at only 22% and has mod - severe valve leakage, not candidate for surgery, what does this mean?

CHF : You need to speak with dad's cardiologist who has all the information about your dad. An ef of 22% with mitral regurgitation in general does not bode well.

Risk too high: To not be a candidate for surgery would mean the risk is too high. It's hard to be more specific without more info. Might be that the surgical risk is too high-->very sick people may not survive major surgery. In general, someone with such poor function would often do better with functioning valves, but a working mitral valve will increase lv workload-->a weak lv may not tolerate it. Best wishes.