I was diagnosed with heart failure back in 2001 and my "die by" date was expected around 2006, I'm still here although a bit creakier. A-fib caused clots to form in my atria one of which made its way to my brain which resulted in a stroke in '11. It was the upset to my system caused by the stroke that left me T2. I was hospitalised over Christmas '12/13 with Stage 3/4 heart failure, ejection factor just 20%. By dint of looking myself better when I had an MRI in summer '14 my ejection factor had improved to 27%. Meanwhile this year I've been fitted with an implanted cardioverter/defibrillator with 3-wire bilateral pacing to resynchronise my heart (ie CRT-D therapy). Basically my left ventricle wasn't being paced by my sinoatrial node but doing its own thing. The ICD has resulted in a great improvement in exercise tolerance, although I'm still having my programming regularly tweaked - yes, I'm officially a cyborg! I'm having an echocardiogram next week, but I understand my heart failure is now Stage 1-2: moderate to good! So yes, as has recently been acknowledged, heart failure can be reversed.
I still do what you can see in my avatar.