What causes heart failure?

Causes of Heart Failure

Heart failure is primarily caused by coronary artery disease, hypertension, and dilated cardiomyopathy, with valvular heart disease also being a common contributor. 1 These conditions lead to structural and functional cardiac abnormalities that impair the heart's ability to fill with or eject blood effectively.

Major Causes of Heart Failure

Primary Cardiovascular Causes:

1. Ischemic Heart Disease

   • Coronary artery disease and myocardial infarction are leading causes 1
   • Results in myocardial injury, scarring, and remodeling

2. Hypertension

   • Long-standing high blood pressure leads to left ventricular hypertrophy and increased afterload 2
   • Causes progressive myocardial rigidity and decreased compliance

3. Valvular Heart Disease

   • Aortic stenosis creates pressure overload
   • Mitral regurgitation causes volume overload
   • Both lead to cardiac remodeling and dysfunction 1

4. Cardiomyopathies

   • Dilated cardiomyopathy (genetic or acquired)
   • Up to 30% of dilated cardiomyopathy cases have genetic causes 1
   • Hypertrophic cardiomyopathy
   • Restrictive cardiomyopathy

Secondary Causes:

1. Metabolic/Endocrine Disorders

   • Diabetes mellitus 3
   • Thyroid disease (both hypo- and hyperthyroidism)
   • Obesity

2. Toxin-Mediated

   • Alcohol-induced cardiomyopathy
   • Chemotherapeutic agents (especially anthracyclines)
   • Illicit drugs (cocaine, methamphetamine)

3. Inflammatory/Infectious

   • Myocarditis (viral, bacterial, autoimmune)
   • Chagas disease
   • COVID-19 related myocardial injury 1

4. Other Causes

   • Tachycardia-induced cardiomyopathy
   • Peripartum cardiomyopathy
   • Infiltrative diseases (amyloidosis, sarcoidosis)
   • Iron overload (hemochromatosis)

Pathophysiological Mechanisms

Heart failure develops through several key pathophysiological mechanisms:

1. Cardiac Remodeling

   • Ventricular dilatation and hypertrophy
   • Changes in cardiac geometry (more spherical shape)
   • Myocyte hypertrophy and interstitial fibrosis 1

2. Neurohormonal Activation

   • Activation of renin-angiotensin-aldosterone system
   • Sympathetic nervous system activation
   • Initially compensatory but eventually detrimental 1
   • Leads to increased fluid retention, vasoconstriction, and further cardiac remodeling

3. Hemodynamic Abnormalities

   • Increased filling pressures
   • Reduced cardiac output
   • Impaired ventricular filling (diastolic dysfunction)
   • Reduced ejection fraction (systolic dysfunction) 1

Clinical Manifestations

The cardinal manifestations of heart failure are:

• Dyspnea (at rest or with exertion)
• Fatigue
• Fluid retention leading to pulmonary congestion and peripheral edema 1

Special Considerations in Specific Populations

Elderly Patients

• Higher prevalence (approximately 20% in those over 75 years) 4
• Often have multiple comorbidities
• May present with atypical symptoms

Patients with Diabetes

• Diabetes independently increases risk of heart failure
• Contributes to heart failure through multiple mechanisms including diabetic cardiomyopathy 3

Racial and Ethnic Disparities

• Non-Hispanic Black patients have the highest death rate per capita from heart failure 1
• Significant disparities exist in hospitalization rates and outcomes

Prevention

Prevention of heart failure should be a primary objective through:

• Early identification and treatment of risk factors
• Aggressive management of hypertension, diabetes, and coronary artery disease
• Lifestyle modifications (diet, exercise, smoking cessation)
• Appropriate treatment of valvular heart disease 1

Heart failure represents a final common pathway for numerous cardiac conditions. Understanding the specific cause in each patient is essential for appropriate management and potentially reversing or slowing progression of the disease.