Your provider will first use the ACC/AHA classification model to diagnose which stage of HF you're experiencing. The NYHA system gets added later on if you are in the later stages of the ACC/AHA ...

Patients with symptomatic (New York Heart Association [NYHA] class III or IV) systolic (left ventricular ejection fraction [LVEF] ≤40%) congestive heart failure (CHF) were randomized to ...