My Mom Is 78 And Has Congestive Heart Failure..EF Is

My mom is 78 and has congestive heart failure..EF is 25..what is generally a life expectancy and can this be improved? She works out hard and it has not helped..it was 35 in March..one side of the heart is damaged from a heart attack..increasing coreg I guess will help..maybe a pacemaker? Seeing a dr. Again thursday but am concerned about her dying from this if it does not improve..could this cause a massive heart attack with low EF of 25?