True, there are people waaliing around with EF% in the 15 % range and don't even know it.
Some patients feel good and remain active in spite of having a low EF.
A study published in the journal Panminerva Medica demonstrates PycnoQ10®, a pycnogenol (French maritime pine bark extract) and coenzyme Q10 (CoQ10) combination, naturally improves heart function. Results showed heart ejection fraction increased by 22.4% in the treatment group whereas only 4% in controls.