What is anaemic heart disease?

Anemic Heart Disease: Definition, Pathophysiology, and Management

Anemic heart disease refers to the pathological condition where anemia coexists with and adversely affects cardiac function, leading to worsened heart failure symptoms, decreased exercise capacity, poor quality of life, and increased mortality and hospitalization rates. 1

Prevalence and Significance

• Anemia is present in approximately one-third of patients with congestive heart failure (CHF) and 10-20% of patients with coronary heart disease (CHD) 1
• The prevalence increases with heart failure severity, advanced age, female gender, and presence of comorbidities like renal dysfunction 1
• Anemia is an independent risk factor for increased hospitalization, mortality, and reduced quality of life in heart failure patients 1, 2

Pathophysiology

Causes of Anemia in Heart Disease

• Multifactorial etiology including:
  • Iron deficiency (most common specific cause) 1, 3
  • Chronic kidney insufficiency (present in about half of all CHF cases) 3
  • Blunted erythropoietin production 1, 3
  • Hemodilution due to fluid retention 1, 2
  • Aspirin-induced gastrointestinal blood loss 1
  • Renin-angiotensin-aldosterone system blockers usage 1
  • Cytokine-mediated inflammation (anemia of chronic disease) 1, 3
  • Gut malabsorption with nutritional deficiency 1

Vicious Cycle of Anemia and Heart Disease

• Anemia worsens cardiac function through:
  • Increased cardiac stress via tachycardia and increased stroke volume 3, 4
  • Reduced renal blood flow leading to fluid retention 3
  • Long-standing anemia causing left ventricular hypertrophy 3
• Heart failure worsens anemia through:
  • Renal vasoconstriction reducing erythropoietin production 3
  • Increased inflammatory cytokines (TNF-alpha, IL-6) interfering with erythropoiesis 3, 5
  • Reduced iron supply to bone marrow 3
• This creates what some researchers term the "cardio-renal anemia syndrome" 3, 4

Clinical Presentation

• Symptoms may include:
  • Worsened heart failure symptoms (dyspnea, fatigue) 1, 3
  • Decreased exercise capacity 1, 2
  • Resistance to standard heart failure medications 3, 4
  • Frequent hospitalizations 1, 3
  • Progressive deterioration of renal function 3, 4

Diagnostic Approach

• Anemia is defined as hemoglobin <12 g/dL in women and <13 g/dL in men 1, 6
• Severity classification:
  • Mild: Hb 10-11.9 g/dL 6
  • Moderate: Hb 8-9.9 g/dL 6
  • Severe: Hb <8.0 g/dL 6
• Diagnostic workup should include:
  • Complete blood count with peripheral blood smear 6
  • Iron studies (serum iron, ferritin, transferrin saturation) 6
  • Assessment for occult blood loss 6
  • Evaluation of renal function 3

Treatment Approaches

Iron Supplementation

• Oral iron supplementation is first-line therapy for iron deficiency 6
• Parenteral iron therapy is indicated with malabsorption or when rapid repletion is needed 6

Blood Transfusions

• The American College of Physicians recommends using a restrictive red blood cell transfusion strategy (trigger hemoglobin threshold of 7-8 g/dL) in hospitalized patients with coronary heart disease 1, 6
• Transfusion therapy should be reserved for severe symptomatic anemia or when rapid correction is needed 6

Erythropoiesis-Stimulating Agents (ESAs)

• The American College of Physicians strongly recommends against the use of ESAs in patients with mild to moderate anemia and heart disease 1
• Despite some small studies showing potential benefits, larger studies have raised concerns about adverse effects including hypertension and thromboembolism 6

Treatment of Underlying Causes

• Addressing renal dysfunction when present 3, 4
• Investigating and treating gastrointestinal blood loss 6
• Managing heart failure optimally to break the vicious cycle 3, 4

Prognosis and Monitoring

• Even small reductions in hemoglobin are associated with worse outcomes in heart failure patients 2
• Regular monitoring of hemoglobin levels and iron status is essential 6
• For iron deficiency anemia: Repeat hemoglobin measurement after 4 weeks of treatment 6

Clinical Pitfalls and Challenges

• Failure to identify and treat the underlying cause can lead to recurrence 6
• ESAs carry risks including hypertension and thromboembolism 6
• Transfusions should be used judiciously due to associated risks 6
• The relationship between anemia correction and improved outcomes in heart failure remains an area of ongoing research 5, 7