Having an EF below 29% is considered to be in the heart failure range indicating the heart is oftened unable to pump strong enough to meet the systems demand for blood/oxygen. Depending on the underlying cause and effective treatment may increase one's prognoses to many years if one hasn't any compromising concomitant health issues. About 6 years ago I had an EF below 29% and congested heart failure, and currently may heart is pumping normally at 59%. The underlying cause was high blood pressure and successfully treated.
If the underlying cause is heart muscle disease, there may not be any effective treatment and under that circumtance the life span is limited unless there is a transplant.
Other factors to be considered is one's age, proper diet, compliance with medication, good caretakers, exercise tolerance, etc. There is no computation that can take into consideration all the dependant variables and provide any significant analysis worthy of any credibility. There are life insurance actuarial tables that may classify all heart attack policy holders equally to increase the premiums without any consideration of mitigating or aggravating dependent variables...I have seen tables that put life expectency of 5 years...but medication has improved, surgical intervention, etc. within the time interval evaluted and are/were not able to assess with all the know medical factors, etc. within their calculation...so premiums remain high.
Thanks for your question.
kenkeith has given you a top-notch reply in my opinion. He is on the money, advancements in Cardiac medications, surgical techniques, diet and exercise. The heart can be repaired in ways that were impossible even ten years ago.
Like kenkeith, I've seen my EF raised greatly. It's not normal, I think 42%, but I'll sure take that compared to where it was!
As kenkeith suggests, be careful looking at the internet research, lots of it quotes outdated material. Marshall Mcluhan, a Futurist back in the day, suggested "We look at the future through a rear-view mirror. We march backwards into the future."
Raising your EF takes work and discipline and expecting the best result. Stay in touch
My daughter, who had a transplant is now walking around and she is able to work part time with a EF% of 15. Her doctors said that that is not the only thing they consider with heart failure now. They consider kidney and lung function along with the EF%. I think too many people are actually doing quite well with low EF%s; many don't even know their EF%s are low and maybe that' s why it is not the only consideration when determining heart failue and the prognosis of the individual patient. You really can't go by what you hear about the life expectancy of the heart failure patient. There are SO MANY variables that come into play along with the fact that doctors really don't know how long any one person will live. Most doctors will tell you they don't even what to try and guess anymore....they've been proven wrong too many times in the past. :)