I am a 47 year old female and I just had a major heart attack, with a semi. My EF is only 30% now. I was blocked 100%. I was told I could live a normal life depending on what lifestyle changes I made, quite smoking, eat heart healthy, ext. That is a est. They can't give you a exact time.
I assume you mean that your heart EF is at 40%.
The ejection fraction (EF) of the heart indicates how well the heart is able to pump out the blood from the left ventricle.
Te norml range of EF is 55-70%, so you are well below that.
If you can keep the EF stable at 40% there is not much reason to assume that you will live shorter than someone with a higher EF. It may restrict you in vigorous exercising, but 40% is normally enough for daily activities.