What are the diagnostic criteria for Rheumatic Heart Disease (RHD)?

Diagnostic Criteria for Rheumatic Heart Disease

The World Heart Federation 2012 criteria remain the gold standard for echocardiographic diagnosis of RHD, requiring pathological valve regurgitation plus morphological features, with recent 2024 updates introducing a stage-based classification system (A-D) that replaces the outdated "borderline" and "definite" terminology. 1, 2

Screening Approach (For Individuals ≤20 Years in High-Prevalence Settings)

A positive screen requires any one of the following 2:

• Mitral regurgitation (MR) jet length ≥1.5 cm for patients <30 kg OR ≥2.0 cm for patients ≥30 kg
• Any aortic regurgitation (AR) jet observed in at least one view for at least two consecutive frames
• Restricted mitral valve leaflet motion with reduced opening

Confirmatory Echocardiographic Criteria (Expert-Performed)

Definite RHD Requires ONE of the Following 1:

A) Pathological MR + ≥2 morphological features of RHD of the mitral valve

B) Mitral stenosis (MS) with mean gradient ≥4 mmHg (must exclude congenital MV anomalies and mitral annular calcification in adults)

C) Pathological AR + ≥2 morphological features of RHD of the aortic valve (must exclude bicuspid AV, dilated aortic root, and hypertension)

D) Borderline disease of BOTH aortic and mitral valves (combined AR and MR in high-prevalence regions without congenital heart disease is considered rheumatic)

Pathological Mitral Regurgitation (ALL Four Criteria Must Be Met) 1:

• Seen in two views
• Jet length ≥2 cm in at least one view (measured from vena contracta to last pixel)
• Velocity ≥3 m/s for one complete envelope
• Pan-systolic jet in at least one envelope

Pathological Aortic Regurgitation (ALL Four Criteria Must Be Met) 1:

• Seen in two views
• Jet length ≥1 cm in at least one view (measured from vena contracta to last pixel)
• Velocity ≥3 m/s in early diastole
• Pan-diastolic jet in at least one envelope

Morphological Features of RHD

Mitral Valve Features 1:

• Anterior mitral valve leaflet (AMVL) thickening (age-specific):
  • ≥3 mm for age ≤20 years
  • ≥4 mm for age 21-40 years
  • ≥5 mm for age >40 years
  • (Measured during diastole at full excursion, at thickest portion including focal thickening/beading/nodularity)
• Chordal thickening
• Restricted leaflet motion (from chordal shortening/fusion, commissural fusion, or leaflet thickening)
• Excessive leaflet tip motion during systole (applies only to age <35 years; a flail leaflet in patients ≤20 years alone is sufficient as a morphological feature)

Aortic Valve Features 1:

• Irregular or focal thickening (note: right and noncoronary cusp closure line often appears echogenic in healthy individuals in parasternal short axis)
• Coaptation defect
• Restricted leaflet motion
• Prolapse

Stage-Based Classification System (2024 Update) 2

Stage A (applies only to age ≤20 years):

• Minimal echocardiographic criteria for RHD met
• Pathological MR or AR present without abnormal morphology
• Low risk of progression based on risk score
• Management: Enroll in RHD registry; secondary antibiotic prophylaxis (SAP) initiation is reasonable (Class 2A)

Stage B: Mild RHD 2

Stage C: Advanced RHD 2

Stage D: Advanced RHD with established complications 2

Technical Requirements 2

Echocardiographic assessment must include:

• 2D echocardiography for morphological assessment
• Continuous-wave Doppler for velocity measurements
• Color-Doppler for regurgitation detection

Critical Clinical Caveats

Age-Related Modifications: Criteria are modified for individuals >20 years because valvular features develop over time 2

Subclinical RHD: RHD detected on echocardiography without a clinically pathological cardiac murmur is termed "subclinical RHD" 2, 3

Prophylaxis Timing: Although confirmatory echocardiography is recommended before SAP initiation, in settings where immediate confirmatory studies are unavailable, SAP can be initiated while awaiting confirmation 2

Image Quality Requirements: Valve thickness can only be assessed if images were acquired at optimal gain settings without harmonics and with frequency ≥2.0 MHz; harmonic imaging measurements should be cautiously interpreted with thickness up to 4 mm considered normal in those ≤20 years 1

Exclusion of Mimics: Always exclude congenital anomalies, degenerative changes, and other causes of valvular disease before diagnosing RHD 1