How reliable is an exercise stress echo in the diagnosis of exercise-induced heart failure with preserved ejection fraction?

This is my understanding of HFpEF.

It is a clinical diagnosis of exertional Dyspnea in patients with risk factors such as HTN, atherosclerosis and Hyperlipidemia, increased BMI, and inactivity.

A new classification means stage A only risk factors, stage B has some organ dysfunction such as LVH, left...