Heart Failure

Key Terms

• GDMT

Epidemiology

• Prevalence:
  • Affects approximately 6.2 million adults in the U.S. (2022 data).
  • Incidence increases with age; most common in patients >65 years.
• Demographics:
  • Higher prevalence in African Americans compared to Caucasians.
  • Slight male predominance in younger patients; more common in women in older age groups.
• Burden:
  • Leading cause of hospitalization in individuals >65 years.
  • 5-year mortality rates: ~50% for advanced heart failure.

Etiology

• Ischemic Causes:
  • Coronary artery disease (most common cause in the U.S.).
  • Myocardial infarction.
• Non-Ischemic Causes:
  • Hypertension.
  • Valvular heart disease (e.g., aortic stenosis, mitral regurgitation).
  • Cardiomyopathies (dilated, hypertrophic, restrictive).
  • Arrhythmias (e.g., atrial fibrillation).
  • Alcohol or drug-induced cardiomyopathy (e.g., cocaine, chemotherapy agents).
• Other:
  • Congenital heart defects.
  • Thyroid disorders (hyperthyroidism, hypothyroidism).
  • Infections (e.g., myocarditis).
  • Peripartum cardiomyopathy.

Pathophysiology

• Underlying Mechanisms:
  • Reduced cardiac output leads to compensatory mechanisms:
    • Sympathetic nervous system activation (increased HR and contractility).
    • Activation of the renin-angiotensin-aldosterone system (RAAS).
• Types of Heart Failure:
  • Heart Failure with Reduced Ejection Fraction (HFrEF): EF ≤ 40%.
  • Heart Failure with Preserved Ejection Fraction (HFpEF): EF ≥ 50%.
  • Heart Failure with Mid-Range Ejection Fraction (HFmrEF): EF 41-49%.
• Key Consequences:
  • Increased afterload and preload.
  • Ventricular remodeling and fibrosis.
  • Pulmonary and systemic congestion.

Signs and Symptoms

• Common Symptoms:
  • Dyspnea on exertion.
  • Orthopnea.
  • Paroxysmal nocturnal dyspnea.
  • Fatigue and weakness.
  • Edema (peripheral, ascites).
• Advanced Symptoms:
  • Unexplained weight gain or loss.
  • Persistent cough or wheezing (due to pulmonary congestion).
  • Confusion (due to hypoperfusion).

Physical Exam

• Vital Signs:
  • Tachycardia.
  • Hypotension or hypertension (depending on disease stage).
• Inspection:
  • Jugular venous distension (JVD).
  • Peripheral edema.
• Palpation:
  • Hepatomegaly.
  • Cool extremities (reduced perfusion).
• Auscultation:
  • S3 gallop (ventricular dysfunction).
  • S4 (diastolic dysfunction).
  • Crackles or rales (pulmonary congestion).

Diagnostic Tests

• Laboratory Tests:
  • BNP/NT-proBNP: Elevated in heart failure.
  • Renal function, liver enzymes, thyroid panel.
• Imaging:
  • Echocardiogram: Gold standard to assess ejection fraction and wall motion.
  • Chest X-ray: Pulmonary congestion, cardiomegaly.
  • Cardiac MRI: Differentiates between ischemic and non-ischemic causes.
• Functional Tests:
  • Stress testing (ischemia evaluation).
  • Six-minute walk test (functional capacity).

Treatments

• Lifestyle Modifications:
  • Sodium restriction (<2g/day).
  • Fluid restriction (1.5–2 L/day in advanced HF).
  • Weight monitoring and physical activity (as tolerated).
• Pharmacologic Therapy (Guideline-Directed Medical Therapy, GDMT):
  • ACE Inhibitors/ARBs/ARNIs: Reduce mortality and morbidity.
  • Beta-blockers: Carvedilol, metoprolol succinate, bisoprolol.
  • Mineralocorticoid Receptor Antagonists (MRAs): Spironolactone.
  • SGLT2 inhibitors: Dapagliflozin, empagliflozin (newer class with mortality benefits).
  • Diuretics: Symptomatic relief for fluid overload (furosemide, torsemide).
• Advanced Therapies:
  • Implantable devices: ICDs, CRTs.
  • Mechanical support: LVADs for advanced HF.
  • Heart transplantation: End-stage cases.

Referrals

• When to Refer:
  • Persistent symptoms despite GDMT.
  • Severe or worsening LV dysfunction (EF < 35%).
  • Frequent hospitalizations or advanced HF symptoms.
  • Consideration for advanced therapies (e.g., LVAD, transplant).
• Specialists:
  • Cardiologist (or advanced heart failure specialist).
  • Cardiac surgeon (if surgical intervention needed).
  • Palliative care (for end-stage HF).

References

Heart Failure References

1. Guidelines and Reviews

• 2022 AHA/ACC/HFSA Guideline for the Management of Heart Failure
  • A comprehensive guideline on preventing, diagnosing, and managing heart failure. View here.
• 2021 ESC Guidelines for the Diagnosis and Treatment of Acute and Chronic Heart Failure
  • European Society of Cardiology’s evidence-based recommendations for heart failure management.

2. SGLT2 Inhibitor Studies

• SGLT-2 Inhibitors in Heart Failure: A Review of Current Evidence
  • Discusses benefits of SGLT2 inhibitors in managing heart failure. View here.
• Dapagliflozin in Heart Failure with Mildly Reduced or Preserved Ejection Fraction
  • Explores dapagliflozin's efficacy in heart failure patients. View here.
• Empagliflozin in Heart Failure with a Preserved Ejection Fraction
  • Examines empagliflozin’s role in heart failure management. View here.

3. Clinical Trials and Advanced Therapies

• The CHIEF-HF Trial: Canagliflozin in Heart Failure
  • Investigates the impact of canagliflozin on symptoms and quality of life. View here.
• Empagliflozin in Patients Hospitalized for Acute Heart Failure
  • Assesses benefits of empagliflozin in acute heart failure cases. View here.

4. Additional Resources

1. Key Perspectives on the 2022 AHA/ACC/HFSA Heart Failure Guideline
2. HFSA Heart Failure Guidelines
3. The Stages of Congestive Heart Failure
4. 2022 Guidelines for the Management of Heart Failure (Video Overview)