Cardiac cachexia is a syndrome of involuntary and progressive loss of body weight, muscle mass, and fat stores occurring as a direct consequence of severe heart disease, most commonly advanced heart failure. It represents a complex metabolic disturbance rather than simple malnutrition: cachexia occurs even when caloric intake appears adequate, driven by a chronic inflammatory state, neurohormonal activation, and reduced gut absorption.
The mechanisms include chronically elevated inflammatory cytokines (TNF-alpha and interleukins) that stimulate muscle protein breakdown, activation of the renin-angiotensin-aldosterone and sympathetic systems, venous congestion and bowel oedema impairing nutrient absorption, and anorexia related to breathlessness, fatigue, and medication side effects. Patients often describe loss of appetite, early satiety, and progressive weakness rather than deliberate dieting.
Cardiac cachexia is associated with a particularly poor prognosis in heart failure. Loss of more than 5% of total body weight over 12 months in the absence of fluid retention is a recognised clinical threshold. Cachexia is found in approximately 10 to 15% of patients with advanced heart failure and is an independent marker of poor survival. It reduces exercise capacity, respiratory muscle strength, and quality of life.
Management focuses on optimising heart failure treatment to improve cardiac output, nutritional support, and rehabilitative exercise. Resistance exercise training can help preserve and rebuild muscle mass. For cardiac arrest survivors with pre-existing heart failure and significant deconditioning, cardiac cachexia should be identified early in the rehabilitation process, as it profoundly affects recovery trajectory.
« Back to Glossary Index