Definition and Pathophysiology

Rheumatic heart disease (RHD) is a chronic sequela of acute rheumatic fever (ARF), an autoimmune disorder triggered by group A Streptococcus (GAS) pharyngitis—not skin infections (though the role of pyodergha is debated in some endemic regions). RHD manifests as permanent structural damage to cardiac valves, primarily affecting the mitral valve (>65% of cases), followed by the aortic valve (~30%), combined mitral–aortic involvement (~20%), and tricuspid/pulmonary valves less commonly.

Pathogenesis:
After GAS pharyngitis, molecular mimicry occurs between streptococcal M-protein antigens and human tissues—particularly valvular endothelium, myosin, and neural tissue. This initiates a T-cell–mediated and antibody-dependent inflammatory response, leading to Aschoff body formation (granulomatous lesions), fibrosis, and progressive valvular deformity over weeks to years. The process is dynamically progressive, with subclinical valve damage often detectable by echocardiography even in the absence of clinical ARF.

Key Clinical Insight: Valvulitis in ARF is typically reversible early on, but repeated episodes accelerate irreversible fibrosis, calcification, and deformity—most commonly resulting in mitral stenosis (MS) decades after initial infection. MS prevalence now exceeds that of mitral regurgitation (MR) in many endemic regions due to improved primary prevention and longer survival with milder initial attacks.

Epidemiology & Risk Stratification

Global Burden

• RHD affects ≥40 million people worldwide, causing ~350,000 deaths annually—98% in low- and middle-income countries (LMICs) [WHO 2023].
• Endemic regions: Sub-Saharan Africa, South Asia (India, Pakistan), Southeast Asia, Pacific Islands (e.g., Fiji, Vanuatu), and Indigenous populations in Australia/New Zealand.
• In the U.S., prevalence among Indigenous populations (e.g., Native Hawaiians, Aboriginal Australians) is 10–100× higher than in non-Indigenous groups.

High-Risk Populations

Clinical Pearl: RHD is now the most common cause of maternal cardiovascular death in several LMICs. In pregnancy, New York Heart Association (NYHA) Class III/IV symptoms correlate strongly with adverse outcomes—fetal loss up to 50% in severe MS.

Clinical Manifestations: From ARF to Chronic RHD

A. Acute Rheumatic Fever (Jones Criteria, AHA 2021 Revision)

Diagnosis requires evidence of preceding GAS infection plus:

• Major Criteria:
  • Carditis (50–75% of first episodes; may present as subclinical myocarditis on echo)
  • Polyarthritis (most common: migratory large-joint involvement)
  • Sydenham’s chorea (delayed onset, 2–6 months post-infection; isolated manifestation in adults)
  • Erythema marginatum (non-pruritic, serpiginous rash)
  • Subcutaneous nodules (over extensor surfaces)
• Minor Criteria: Fever, arthralgia, prolonged PR interval, elevated acute-phase reactants.

Diagnostic Caveat: Echocardiography has revolutionized carditis diagnosis. Subclinical RHD (valve thickening ± regurgitation without murmur) is detected in 2–15% of schoolchildren in endemic areas—diagnosed only by echo. The WHOecho criteria define abnormal valves as:

• Mitral valve thickness ≥4 mm + regurgitation
• Aortic valve thickening ± regurgitation

B. Chronic Rheumatic Heart Disease

Valve pathology dictates symptoms:

Critical Insight: RHD-related AF occurs in 20–40% of adults with MS, significantly increasing stroke risk (5× higher). Anticoagulation is indicated if CHA₂DS₂-VASc ≥2—regardless of rhythm, per 2020 ESC Valvular Heart Disease Guidelines.

Diagnostic Workup: Evidence-Based Approach

Emerging Tool: Strain echocardiography detects subclinical myocardial dysfunction in ARF even with preserved LVEF—may predict long-term adverse remodeling [Zhou et al., JACC: Cardiovasc Imaging 2023].

Management: From Acute Phase to Long-Term Care

1. Acute ARF Treatment

• Antibiotics:
  • First-line: Benzathine penicillin G 1.2 MU IM ×1 (or 600,000 units if <27 kg).
  • Penicillin-allergic: Azithromycin 12 mg/kg day 1 (max 500 mg), then 6 mg/kg days 2–5 (max 250 mg/day).
• Anti-inflammatory therapy:
  • Aspirin (80–100 mg/kg/day in 4 doses) for arthritis/carditis without heart failure.
  • Prednisone (1–2 mg/kg/day, max 60 mg/day) for severe carditis—taper over 2–3 weeks [Baddour et al., Circulation 2021].

Controversy: Corticosteroids reduce carditis duration but may increase recurrence risk—reserve for moderate-severe carditis with decompensation.

2. Secondary Prophylaxis

• Benzathine penicillin G IM every 3–4 weeks remains cornerstone.
• Alternatives: Oral phenoxymethylpenicillin daily (125–250 mg BID), or sulfadiazine in penicillin allergy.
• Duration: Minimum 10 years after last episode or until age 21, whichever is longer—lifelong if RHD present (ESC 2021).

Real-world data: adherence <80% correlates with 3× higher recurrence risk [Carapetis et al., Lancet Infect Dis 2022].

3. RHD-Specific Management

Surgical Note: In LMICs, mechanical valves are favored over bioprostheses due to younger age and high reoperation risk—despite anticoagulation challenges. Warfarin targeting INR 2.5–3.0 is standard.

Pregnancy Management in RHD

Preconception Counseling

• Echo evaluation: Focus on valve gradients, LA size, pulmonary pressures.
• Optimize HF meds: Avoid ACEi/ARB (teratogenic); use labetalol, nifedipine.
• Ensure secondary prophylaxis compliance.

Antepartum Monitoring

Delivery Planning

• Vaginal delivery preferred with assisted second stage (forceps/episiotomy) to minimize cardiac load.
• C-section indicated for: Severe MS (LVEDP >25 mmHg), HF class III/IV, or mechanical valve with high bleed risk.
• Anesthesia: Regional block preferred—avoid rapid fluid shifts.

Mortality data: Maternal mortality in RHD pregnancy ranges from 0.5% (mild disease) to >30% (severe MS with LVEF <40%) [Ramesh et al., Eur Heart J 2022].

Complications: Beyond Valve Failure

1. Heart Failure
   • Diastolic dysfunction dominates in MS; systolic failure in advanced MR/AS.
   • B-type natriuretic peptide (BNP) >100 pg/mL predicts decompensation.
2. Infective Endocarditis (IE)
   • Risk: 3–6× higher than general population—especially with prosthetic valves, MS, or MR.
   • Prevention: Antibiotic prophylaxis for high-risk procedures only (per AHA/ESC guidelines).
   • Treatment: Blood cultures ×3; IV penicillin + gentamicin for native valve IE; daptomycin for MRSA.
3. Thromboembolism
   • LA thrombus risk: 15–20% in MS with AF or LAD >55 mm.
   • Echo criteria for thrombus: Spontaneous echo contrast (“smoke”) + LA volume index >34 mL/m².
4. Sudden Cardiac Death
   • Associated with severe MR, LV dilation (LVEDD >60 mm), and prior AF.

Global Prevention Strategies: Evidence-Based Priorities

1. Primary Prevention:
   • Rapid diagnosis/treatment of GAS pharyngitis (<9 days from symptom onset).
   • Point-of-care rapid antigen tests (sensitivity >90% for pharyngeal S. pyogenes).
   • Public health interventions: Overcrowding reduction, WASH programs.
2. Secondary Prevention:
   • Active case finding via echo screening in endemic areas (e.g., Nigeria reduced prevalence from 13.8‰ to 6.7‰ with school-based programs) [Carapetis et al., Bull WHO 2021].
   • Registry-based prophylaxis monitoring: Digital adherence tools improve follow-up.
3. Tertiary Prevention:
   • Integrated care pathways: Cardiology + primary care coordination for long-term anticoagulation, HF management.
   • Tele-echo in remote regions: Enables early detection of progressive valve disease.

WHO 2023 Roadmap: Targets a 25% reduction in RF/RHD mortality by 2030 via scalable interventions—emphasizing equity for Indigenous populations and refugees.

Key Clinical Pearls

• Silent RHD is common: Echo-detected RHD without murmur occurs in 25–40% of endemic regions (echo screening detects subclinical disease missed by auscultation).
• RF diagnosis requires Jones criteria: Major manifestations: carditis, polyarthritis, chorea, subcutaneous nodules, erythema marginatum. Minor: fever, arthralgia, PR prolongation, elevated ESR/CRP + precedencing GAS infection.
  • Carditis: Most severe in young children; often includes mitral + aortic regurgitation.
• Rheumatic chorea: May present without carditis—diagnose if other Jones criteria met or GAS serology positive.
• Recurrent RF risk: Up to 50% within 5 years without prophylaxis.

Conclusion

RHD remains a preventable global health disparity, with implications for cardiology, maternal-fetal medicine, and public health. Advances in echocardiography, valve interventions, and prophylaxis protocols have transformed outcomes—but success hinges on early detection, sustained secondary prevention, and context-specific implementation in resource-limited settings. Clinicians must advocate for integrated care models that bridge primary care, specialist services, and community health to eliminate this disease.

References

• Baddour LM, et al. Circulation. 2021;143(16):e578–e614. (AHA Scientific Statement)
• Carapetis JR, et al. Bull World Health Organ. 2021;99:832–842. (WHO RHD Elimination Framework)
• Ramesh S, et al. Eur Heart J. 2022;43(35):3476–3487. (Pregnancy in RHD)
• Zaidi SIA, et al. Lancet Glob Health. 2023;11(2):e192–e201. (Global echo screening data)
• WHO. Global Report on Rheumatic Heart Disease. 2023.