What is rheumatic heart disease?

Rheumatic Heart Disease: Pathophysiology, Diagnosis, and Management

Rheumatic heart disease (RHD) is a chronic valvular heart disease resulting from an autoimmune response to group A β-haemolytic streptococcal (GAS) throat infection, causing progressive valve damage that predominantly affects the mitral valve followed by the aortic valve. 1, 2

Pathophysiology

• RHD begins with acute rheumatic fever (ARF), an autoimmune disease that follows GAS pharyngitis in genetically susceptible individuals 1, 2
• After recovery from the initial episode of ARF, 60-65% of patients develop valvular heart disease 1, 2
• The disease process involves an abnormal immune response that causes inflammation, scarring, and eventual calcification of heart valves 1, 3
• Rheumatic AS (aortic stenosis) results from fusion of the commissures with scarring and eventual calcification of the cusps, and is invariably accompanied by mitral valve disease 1
• Left-sided cardiac valves are predominantly affected, with the mitral valve being most commonly involved 2

Clinical Manifestations

• Progressive valve damage leads to valvular stenosis and/or regurgitation 2
• As RHD progresses, it can cause several serious complications:
  • Atrial fibrillation due to left atrial enlargement 2, 4
  • Heart failure from volume or pressure overload 2, 4
  • Infective endocarditis on damaged valves 2
  • Stroke from thromboembolic events 2, 4
  • Pregnancy-related complications in women 2, 4
• Symptoms may include dyspnea, palpitations, chest pain, syncope, fatigue, and exercise intolerance 4

Epidemiology

• RHD remains the most common cardiovascular disease in young people aged <25 years globally 1, 2
• The disease disproportionately affects populations in low and middle-income countries and some indigenous communities in high-income countries 2, 5
• RHD is influenced by socioeconomic factors, including poor living conditions and limited access to healthcare 2, 5
• It causes most of the cardiovascular morbidity and mortality in young people, leading to about 250,000 deaths per year worldwide 6, 7

Diagnosis

• The World Heart Federation has established echocardiographic criteria for RHD diagnosis with three categories: 'definite RHD', 'borderline RHD', and 'normal' 1
• Echocardiography is more sensitive and specific than auscultation for detecting RHD 1
• RHD detected on echocardiography without an associated clinically pathological cardiac murmur is referred to as 'subclinical RHD' 1
• Diagnosis may be made through clinical findings or echocardiography, especially if there is no clear history of ARF 4

Prevention and Management

• Primary prevention involves prompt recognition and treatment of GAS pharyngitis 1
• Secondary prevention is crucial for patients who have had rheumatic fever:
  • Patients who have had rheumatic fever with or without carditis (including patients with mitral stenosis) should receive prophylaxis for recurrent rheumatic fever 1
  • Continuous antimicrobial prophylaxis with penicillin has been shown to be effective 1, 8
• The World Heart Federation has set strategic targets including:
  • Comprehensive register-based control programs 1
  • Global access to benzathine penicillin G 1
  • Identification and development of public figures as 'RHD champions' 1
  • Expansion of RHD training hubs 1
  • Support for vaccine development 1

Pitfalls and Caveats

• Despite being preventable, RHD remains neglected in many healthcare systems 5, 6
• Funding for RHD research and control is disproportionately low compared to other diseases 1
• Many patients present late with advanced disease, when valve damage is irreversible 1, 8
• Early detection through echocardiographic screening is important but implementation in resource-limited settings remains challenging 1, 8
• Long-term adherence to secondary prophylaxis is essential but often suboptimal 4