I have HFpEF too.
Cardio tells me it is likely the result of the remodeling of my heart due to Afib.
I recent study done is Australia seems to show that eliminate the Afib can cause the remodeling to be reversed.

Something is causing the heart to change. Hypertension? Kidney failing function? Many choices….but the deal is to first eliminate or reduce the cause, then fix your diet so that you eliminate the salt and other risk factors.

My cardiologist only prescribes drugs…I read the latest studies to try to understand how to help myself. I am on Lasix and Jardiance…mostly to deal with sodium…. Otherwise the medical profession has no real answers and certainly no in depth understanding of why the remodeling occurs…just correlation.

Slowing the progress of this HF is a big issue for me. The impact is the constant breathlessness. Once I realized that it was not my lungs failing..but blood circulation (rather failure to move blood effectively)…I came to understand that no amount of strenuous exercise would change it. But..I remain active and just put up with constantly having to stop to catch my breath