Excellent article and excellent research study.
My husband lived for many, many years with heart failure. And he did have restrictive/constrictive heart failure.
He was on massive amounts of diuretics and they helped, but didn't eliminate the problem. It got better, then got worse again, then better, then worse. It seemed like each time he lost a tiny bit of ground. I kept him on a diet which had almost no salt or sodium, only enough to keep him relatively healthy. It was much lower than the Heart Assoc. recommends, way below 1000mg per day. That also helped, but he still had a terrible battle.
Eventually his kidneys just couldn't take it anymore, and he ended up on dialysis.
It will be interesting for me to see what treatments are finally developed to combat this problem.
It was clear to me that the current medications just didn't address that level of heart failure, and Joe was under the care of an expert in heart failure.