What is the definition of heart failure and when should it be coded in patients, particularly those with a history of hypertension, diabetes, or coronary artery disease (CAD)?

Definition of Heart Failure and When to Code

Heart failure should be coded when a patient has both typical symptoms (breathlessness, fatigue, or ankle swelling) AND objective evidence of cardiac structural/functional abnormality at rest, corroborated by elevated natriuretic peptides and/or evidence of congestion—simply having risk factors like hypertension, diabetes, or CAD without these criteria does NOT constitute heart failure. 1

Core Diagnostic Requirements for Coding

Heart failure is a clinical syndrome, not merely an imaging finding or risk state. To appropriately code for heart failure, all three components must be present 2:

• Symptoms: Breathlessness at rest or on exertion, fatigue, tiredness, ankle swelling 1
• Signs: Elevated jugular venous pressure, pulmonary crackles, peripheral edema, tachycardia, pleural effusion, hepatomegaly 1
• Objective cardiac abnormality: Demonstrated by echocardiography showing reduced ejection fraction, left ventricular hypertrophy, diastolic dysfunction, valvular disease, OR elevated natriuretic peptides (BNP/NT-proBNP) 3, 4

Critical pitfall: Asymptomatic left ventricular dysfunction or structural heart disease alone is NOT heart failure—these patients are classified as Stage B (Pre-HF) and should not be coded as having heart failure 2, 3.

When NOT to Code Heart Failure

Stage A: At Risk for Heart Failure

Patients with hypertension, diabetes, CAD, obesity, or metabolic syndrome without structural heart disease or symptoms are at risk but do NOT have heart failure 2. These patients should not receive a heart failure diagnosis code.

Stage B: Pre-Heart Failure

Patients with structural heart disease (LV remodeling, LVH, reduced ejection fraction, asymptomatic valvular disease) but without current or prior symptoms are classified as Pre-HF 2, 3. This is a precursor state, not heart failure itself.

Key distinction: A normal ECG makes heart failure unlikely, and low-normal natriuretic peptides in an untreated patient essentially rule out heart failure 1.

Classification When Coding IS Appropriate

Once the diagnosis is established, heart failure must be further classified:

By Ejection Fraction (Required)

• HFrEF: LVEF ≤40% 3, 4
• HFmrEF: LVEF 41-49% 3, 4
• HFpEF: LVEF ≥50% 3, 4
• HFimpEF: Baseline LVEF ≤40% with ≥10 point increase to >40% 4

By Functional Status (NYHA Class)

• Class I: No limitation of physical activity 1
• Class II: Slight limitation, comfortable at rest 1
• Class III: Marked limitation, comfortable only at rest 1
• Class IV: Unable to carry out any activity without discomfort, symptoms at rest 1

By Stage (Unidirectional Progression)

• Stage C: Symptomatic HF with structural heart disease 2, 3
• Stage D: Advanced/refractory HF requiring specialized interventions, recurrent hospitalizations 2, 3

Essential Diagnostic Workup Before Coding

The following must be documented to support a heart failure diagnosis code 2:

• History: Symptoms (dyspnea, fatigue, edema), functional capacity, alcohol/drug use, cardiotoxin exposure 2
• Physical exam: Volume status, orthostatic blood pressure, weight, BMI, jugular venous pressure 2
• Laboratory: Complete blood count, electrolytes (including calcium/magnesium), renal function, glucose, lipids, liver function, TSH 2
• ECG: 12-lead electrocardiogram (normal ECG makes HF unlikely) 2, 1
• Imaging: Two-dimensional echocardiography with Doppler to assess LVEF, chamber size, wall thickness, valve function 2
• Biomarkers: BNP or NT-proBNP (essential for diagnosis confirmation) 3, 4

Etiology Documentation

Heart failure should never be coded as the sole diagnosis—the underlying cause must be identified and coded 2:

• Ischemic cardiomyopathy (most common, ~40% of cases) 5
• Hypertensive heart disease (17-31% of cases) 5
• Idiopathic dilated cardiomyopathy 5
• Valvular disease 5
• Other specific causes (peripartum, genetic, cardiotoxic) 5

The specific etiology determines treatment and prognosis, making this distinction clinically essential 3.

Special Considerations

Accuracy of clinical diagnosis alone is inadequate, particularly in women, elderly, and obese patients—objective testing is mandatory 2. The diagnosis requires clinical judgment integrating history, examination, and appropriate investigations 2.

Response to diuretics or nitrates alone is insufficient for diagnosis, though patients should generally demonstrate improvement with appropriate therapy 2.