Cardiac Cachexia

KEY FEATURES

ESSENTIALS OF DIAGNOSIS

• Chronic severe heart failure

• Nonedematous, unintentional body weight loss of > 5% in < 12 months

• Decrease in muscle strength, fatigue, anorexia, low fat-free muscle index, abnormal biochemistry (inflammation, anemia, low serum albumin)

GENERAL CONSIDERATIONS

• Affects up to 10% of symptomatic patients with chronic heart failure (CHF)

• Associated with very poor survival

• Pathophysiology of wasting is not certain, but likely involve mediators of altered appetite and food intake, abnormal lipid and glucose metabolism, or anabolic or catabolic regulators

• Treatment involves medical optimization of CHF and replacement of detectable vitamin deficiencies

CLINICAL PRESENTATION

SYMPTOMS AND SIGNS

• Patient with CHF

• Early fatigue with exercise

• Muscle weakness

• Loss of appetite

• Preserved or deteriorating appetite

• Muscle wasting/atrophy

• Loss of adipose tissue

DIFFERENTIAL DIAGNOSIS

• Malignancy

• Hyperthyroidism

• Acquired immunodeficiency syndrome

• Intentional weight loss or starvation

• Diuresis

• Infection

DIAGNOSTIC EVALUATION

LABORATORY TESTS

• Hyponatremia

• Elevated serum uric acid

• Elevated C-reactive protein and erythrocyte sedimentation rate

• Elevated serum creatinine

• Elevated triglycerides

• Low serum albumin

• Anemia

ELECTROCARDIOGRAPHY

• Sinus rhythm/sinus tachycardia

• Atrial fibrillation

• Low-voltage QRS or evidence of ventricular hypertrophy

IMAGING STUDIES

• Chest x-ray: normal or enlarged cardiac silhouette, pulmonary vascular congestion and/or curly B lines; osteopenia with or without vertebral body compression fractures

• Echocardiography: biventricular and/or right ventricular enlargement and reduced contractility; atrial enlargement; color Doppler evidence of valvular regurgitation due to annular dilatation; mitral, pulmonary venous, and tissue Doppler evidence of left ventricular diastolic dysfunction with elevated filling pressures; elevated Doppler tricuspid regurgitant peak velocity indicating pulmonary hypertension; plethoric inferior vena cava

• Other diagnostic tests directed at excluding malignancy and other noncardiac causes of cachexia

DIAGNOSTIC PROCEDURES

• No specific diagnostic procedures

TREATMENT

CARDIOLOGY REFERRAL

• Most patients with chronic heart failure should be followed up by a cardiologist

HOSPITALIZATION CRITERIA

• Syncope

• Decompensated CHF

• Severe or symptomatic hypotension

MEDICATIONS

• Optimization of goal-directed medical therapy for CHF

• Omega-3 polyunsaturated fatty acids

• Antioxidants (vitamins C and E)

• Protein supplementation of 1.0–1.2 g per kg body weight

• Anabolic steroids and recombinant human growth hormone can be considered

• Avoid drugs that worsen anorexia

MONITORING

• Weight

• Fluid and nutritional intake

DIET AND ACTIVITY

• Nutritional support (40–50 kcal/m² of body surface per hour including 1.0–1.2 g/kg body weight protein)

• Two-gram dietary sodium restriction

• Exercise training for CHF patients in New York Heart Association (NYHA) functional classes I–III