Table 1.

Complexities with Current HF Nomenclature

Current HF Terminology	Challenges with Use
Ejection Fraction	• Fails to reflect underlying biology or pathophysiology
	• Specific thresholds are arbitrarily selected
	• Depends on loading conditions and arrhythmia status
	• The conventional and widely used 2D echocardiographic assessment subject to intra- and inter-observer variability and variability in the quality of image acquisition
NYHA Functional Class	• Depends on congestive status
	• Symptoms and functional status may be limited by comorbidities
	• Subjective and variably graded by clinicians
	• Dynamic and labile over the short-term
Stage B HF	• Uncertain application to HF with preserved ejection fraction
	• Use of more sensitive imaging modalities may expand this population
	• Non-structural changes may represent clinically-relevant pre-clinical states (e.g., atrial arrhythmias)
Advanced / Stage D HF	• Depends on treatment intensity (i.e., use of inotropes or mechanical circulatory support)
	• Depends on response to therapies (i.e., lack of adequate response or intolerance to evidence-based therapies)
	• May not correlate with cardiopulmonary exercise testing
Acute HF and Worsening HF	• Generally defined as synonymous with a hospitalization for HF and subject to wide regional and practice-based variation in thresholds for hospitalization
	• Similar level of care and acuity may be managed in the outpatient setting in some practices
	• Decision to hospitalize a patient for HF dependent on many factors other than the severity of the HF presentation, including age, comorbidities, and non-clinical factors (e.g., patient preference, patient living/social situation, physician/hospital financial incentives)

Abbreviations: HF = heart failure

NYHA = New York Heart Association