Best Mitral Heart Valve Replacement doctors in Istanbul

My wife aged 60 is having slow pumping of blood in the left ventricle after taking ecg, echo and angiogram etc. The functioning of the heart is 65%. As per the cardiologist advice she is taking tablets. It may kindly be advised whether the tablets will speed up the functioning of the heart of otherwise any other treatment I have to undergo. Your advice is earnestly solicited. Suggest the treatment and hospitals.