Heart Failure: HFrEF and HFpEF Classification and Treatment

Heart failure is a complex clinical syndrome characterized by the inability of the heart to pump blood adequately to meet the metabolic demands of the body. The condition affects over 6 million Americans and represents a leading cause of hospitalization in patients over 65 years.

[KEY_CONCEPT] Heart failure is classified based on left ventricular ejection fraction (LVEF):

Epidemiology:

• Incidence: 10 per 1,000 population after age 65
• 5-year mortality: 50% overall
• HFpEF more common in elderly women with hypertension and diabetes
• HFrEF more common in men with coronary artery disease

[HIGH_YIELD] Key etiologies include:

• HFrEF: Ischemic cardiomyopathy (70%), dilated cardiomyopathy, viral myocarditis
• HFpEF: Hypertensive heart disease, hypertrophic cardiomyopathy, restrictive cardiomyopathy

Pathophysiology involves activation of neurohormonal systems including the renin-angiotensin-aldosterone system (RAAS) and sympathetic nervous system, leading to progressive ventricular remodeling, increased afterload, and fluid retention.

Heart failure presents with a constellation of symptoms and signs reflecting fluid overload and reduced cardiac output.

Symptoms:

• Dyspnea: Exertional → orthopnea → paroxysmal nocturnal dyspnea
• Fatigue and exercise intolerance
• Lower extremity edema
• Abdominal distension (ascites)
• Nocturia and oliguria

[CLINICAL_PEARL] The Framingham criteria remain useful for clinical diagnosis, requiring 2 major or 1 major + 2 minor criteria.

Physical Examination Findings:

[HIGH_YIELD] NYHA Functional Classification:

• Class I: No limitation of physical activity
• Class II: Slight limitation; comfortable at rest
• Class III: Marked limitation; comfortable only at rest
• Class IV: Unable to perform any physical activity without discomfort

Red flag symptoms requiring immediate evaluation:

• Acute dyspnea at rest
• Syncope or near-syncope
• Chest pain with hemodynamic compromise
• Signs of cardiogenic shock (hypotension, altered mental status, cool extremities)

Initial Diagnostic Workup should establish the diagnosis, determine etiology, and assess severity.

Diagnostic Algorithm for Heart Failure

1. Clinical Assessment ↓
2. 12-lead ECG + CXR ↓
3. BNP/NT-proBNP ↓
4. Echocardiography (LVEF assessment) ↓
5. Laboratory Studies ↓
6. Additional Studies (if indicated)

Laboratory Studies:

• BNP >400 pg/mL or NT-proBNP >2000 pg/mL strongly suggests HF
• CBC: Anemia evaluation
• CMP: Renal function, electrolytes
• TSH: Thyroid dysfunction
• Lipid panel: CAD risk stratification
• HbA1c: Diabetes screening
• Urinalysis: Proteinuria assessment

[KEY_CONCEPT] Diagnostic Criteria for HFpEF (2016 ESC Guidelines):

Required Criteria:

• Signs/symptoms of heart failure
• LVEF ≥50%
• Elevated natriuretic peptides (BNP >35 pg/mL or NT-proBNP >125 pg/mL)
• Evidence of structural heart disease and/or diastolic dysfunction

Imaging Studies:

• Echocardiography: LVEF, wall motion, diastolic function, valve assessment
• Cardiac catheterization: If ischemic etiology suspected
• Cardiac MRI: Tissue characterization, infiltrative disease
• Stress testing: Functional assessment, ischemia evaluation

[HIGH_YIELD] Differential Diagnosis:

• Pulmonary edema from non-cardiac causes
• Chronic kidney disease with fluid overload
• Liver cirrhosis with ascites
• Pulmonary embolism
• Pneumonia with pleural effusion

Guideline-Directed Medical Therapy (GDMT) for HFrEF follows evidence-based treatment algorithms with proven mortality benefit.

HFrEF Treatment Algorithm

1. ACE-I/ARB/ARNI + Beta-Blocker ↓
2. Add MRA (if EF ≤35%) ↓
3. Consider SGLT2-I (if appropriate) ↓
4. If EF ≤35% despite optimal therapy: → ICD consideration → CRT-D if QRS ≥120ms + LBBB ↓
5. Advanced therapies if Stage D

First-Line Therapies:

[HIGH_YIELD] PARADIGM-HF trial demonstrated superior outcomes with sacubitril-valsartan compared to enalapril (16% reduction in cardiovascular death/HF hospitalization).

Second-Line Therapies:

• MRA (spironolactone, eplerenone): 15% mortality reduction if EF ≤35%
• SGLT2 inhibitors (dapagliflozin, empagliflozin): DAPA-HF showed 26% reduction in cardiovascular death/HF hospitalization

Device Therapy:

• ICD: Primary prevention if EF ≤35% despite 3 months optimal therapy
• CRT-D: If EF ≤35%, QRS ≥120ms, LBBB morphology, NYHA Class II-IV

[CLINICAL_PEARL] Medication titration should target maximum tolerated evidence-based doses:

• ACE-I: Lisinopril 20-40mg daily
• Beta-blocker: Metoprolol XL 200mg daily or Carvedilol 50mg BID
• MRA: Spironolactone 25-50mg daily

HFpEF management focuses on symptom control and treatment of comorbidities, as no therapies have definitively shown mortality benefit.

Treatment Priorities:

HFpEF Management Approach

1. Volume Management ↓
2. Comorbidity Treatment ↓
3. Symptom-Directed Therapy ↓
4. Consider SGLT2-I ↓
5. Clinical Trial Participation

Evidence-Based Therapies:

Comorbidity Management:

• Hypertension: Aggressive BP control (target <130/80 mmHg)
• Diabetes: HbA1c <7%, prefer SGLT2 inhibitors or GLP-1 agonists
• Atrial fibrillation: Rate/rhythm control, anticoagulation
• Sleep apnea: CPAP therapy
• Obesity: Weight loss counseling, bariatric surgery consideration

[KEY_CONCEPT] Diuretic therapy remains the cornerstone for symptom management:

• Loop diuretics: Furosemide 20-80mg daily (titrate to euvolemia)
• Thiazide/chlorthalidone: For additional BP control
• Monitor renal function and electrolytes closely

Novel Therapies Under Investigation:

• Finerenone: Selective MRA with potential benefit
• Vericiguat: Soluble guanylate cyclase stimulator
• Exercise training: Structured cardiac rehabilitation

[CLINICAL_PEARL] Unlike HFrEF, ACE inhibitors and beta-blockers do not provide mortality benefit in HFpEF but may be used for comorbidity management.

Acute Complications require immediate recognition and management:

Acute Decompensated Heart Failure (ADHF):

• Precipitants: Medication noncompliance, dietary indiscretion, infection, MI, arrhythmias
• Management: IV diuretics, vasodilators (if appropriate), identify/treat precipitants
• Monitoring: Daily weights, strict I/O, electrolytes

Chronic Complications:

Prognostic Factors:

Poor Prognosis Indicators:

• Advanced NYHA class (III-IV)
• Low LVEF (<30% in HFrEF)
• Elevated BNP/NT-proBNP despite therapy
• Renal dysfunction (eGFR <30 mL/min/1.73m²)
• Hyponatremia (<135 mEq/L)
• Multiple hospitalizations

[HIGH_YIELD] Seattle Heart Failure Model provides validated risk stratification incorporating multiple variables for 1, 2, and 5-year survival estimates.

Advanced Heart Failure (Stage D):

• Refractory symptoms despite optimal GDMT
• Recurrent hospitalizations
• Consider: Heart transplantation, LVAD, palliative care

Prognosis by Classification:

• HFrEF: 5-year survival ~50%, better with optimal GDMT
• HFpEF: 5-year survival ~65%, limited therapeutic options

[CLINICAL_PEARL] Transition to palliative care should be considered when life expectancy is <1 year despite optimal therapy, with focus on symptom management and quality of life.