Just a FYI: Cardiac Microvascular Disease ( Cardiac Syndrome X) can cause CHF with a normal EF - HFpEF.
MVD (MicroVascular Disease) is very common in women. The very small blood vessels in the heart are clogged with plaque and can not be stented. This can and does cause angina (heart pain). This condition can only be controlled by medication. And this condition can be systemic. Called small vessel disease and common with aging as well. I have both Cardiac MVD and small vessel disease in my brain.
A woman with this condition, and with a "normal" EF can go into CHF.
Yes, it's wonderful you are going (or with already) the Mayo Clinic. My personal feeling is - when it comes to your heart - you want to be treated by only the very best medical facilities in the country.
But truthfully I feel that way with any serious medical condition!
All the best to you.