I am in pre CABG with an EF of 55% is it risky undergoing for surgery? What are the complications?

EF or ejection fraction is the amount of blood ejected with each beat of the heart. An ejection fraction of 55 – 60 per cent is normal. A low EF, below 30 or 35 per cent has a higher risk for any surgery including cardiac surgery. The risks are of more complications with surgery such as heart failure, forming of a blood clot, or a stroke.