What are the stages of tricuspid regurgitation (TR)?

Staging of Tricuspid Regurgitation

The 2014 AHA/ACC guidelines establish a four-stage classification system (A through D) for tricuspid regurgitation that progresses from patients at risk through symptomatic severe disease, guiding both surveillance and intervention timing. 1

Stage A: At Risk of TR

Patients have risk factors for TR but no or only trace regurgitation present. 1

Primary TR Risk Factors:

• Mild rheumatic valve changes 1
• Mild leaflet prolapse 1
• Infective endocarditis with vegetation 1
• Early carcinoid deposition 1
• Radiation exposure 1
• Intra-annular RV pacemaker or ICD leads 1
• Post-cardiac transplant (biopsy-related damage) 1

Functional TR Risk Factors:

• Normal valve anatomy with early annular dilation 1
• No hemodynamic consequences or symptoms at this stage 1

Stage B: Progressive TR

Patients have mild-to-moderate TR with early structural changes but remain asymptomatic. 1

Valve Anatomy:

Primary TR:

• Progressive leaflet deterioration or destruction 1
• Moderate-to-severe prolapse with limited chordal rupture 1

Functional TR:

• Early annular dilation 1
• Moderate leaflet tethering 1

Hemodynamic Parameters:

Mild TR:

• Central jet area <5.0 cm² 1
• Soft, parabolic continuous wave (CW) jet density and contour 1
• Hepatic vein flow shows systolic dominance 1

Moderate TR:

• Central jet area 5-10 cm² 1
• Vena contracta width <0.70 cm 1
• Dense CW jet with variable contour 1
• Hepatic vein flow shows systolic blunting 1

Hemodynamic Consequences:

• RV/RA/IVC size remains normal 1
• No RV enlargement 1
• No or mild RA enlargement 1
• Normal RA pressure 1

Stage C: Asymptomatic Severe TR

Patients have severe TR by echocardiographic criteria but no symptoms attributable to right heart failure. 1

Valve Anatomy:

Primary TR:

• Flail or grossly distorted leaflets 1

Functional TR:

• Severe annular dilation (>40 mm or >21 mm/m²) 1
• Marked leaflet tethering 1

Hemodynamic Parameters:

• Central jet area >10.0 cm² 1
• Vena contracta width >0.7 cm 1
• Dense, triangular CW jet with early peak 1
• Hepatic vein flow shows systolic reversal 1

Hemodynamic Consequences:

• RV/RA/IVC dilated 1
• Decreased IVC respirophasic variation 1
• Elevated RA pressure with prominent "c-V" waves 1

Stage D: Symptomatic Severe TR

Patients have severe TR with symptoms of right heart failure, representing the most advanced stage requiring intervention. 1

Valve Anatomy and Hemodynamics:

• Identical echocardiographic criteria to Stage C (central jet area >10.0 cm², vena contracta >0.7 cm, systolic flow reversal in hepatic veins) 1
• RV/RA/IVC dilation with decreased IVC respirophasic variation 1

Cardinal Symptoms:

• Fatigue and reduced exercise capacity 1, 2
• Palpitations (particularly with atrial fibrillation, present in 70-88% of severe TR patients) 2
• Dyspnea with exertion or at rest 1, 2
• Abdominal bloating and fullness from hepatic congestion 1, 2
• Anorexia from splanchnic congestion 1, 2
• Peripheral edema 1, 2

Critical Clinical Point:

Patients with signs or symptoms of right heart failure are classified as Stage D even if they do not meet all other hemodynamic or morphological criteria for severe TR. 1

Clinical Implications by Stage

Surveillance:

• Stage A: Monitor for progression of risk factors 1
• Stage B: Serial echocardiography to assess progression 1
• Stage C: Close monitoring with consideration for intervention timing 1
• Stage D: Urgent surgical evaluation indicated 1, 3

Intervention Timing:

Tricuspid valve surgery is recommended (Class I) for patients with severe TR (Stage D) at the time of left-sided valve surgery. 1, 3

Concomitant tricuspid repair should be considered when tricuspid annular diameter is ≥40 mm (or ≥21 mm/m²) at the time of left-sided valve surgery, as TR often persists or progresses even after successful treatment of left-sided lesions. 4

Common Pitfalls

• Do not rely solely on murmur presence: A systolic murmur may be inaudible even with severe TR; elevated jugular venous pressure with prominent "c-V" waves may be the only clinical clue. 1, 2

• Do not delay surgical referral in Stage D: Severe TR is associated with poor prognosis independent of age, LV and RV function, and RV size, with heart failure being the most common cause of death (50%). 1, 5

• Do not underestimate functional TR: Approximately 80% of significant TR is functional in nature, related to tricuspid annular dilation and leaflet tethering from RV remodeling. 1

• Recognize that the tricuspid annulus often does not return to normal size after relief of RV overload: The annulus becomes planar and circular as it dilates, losing its normal saddle-shaped configuration. 1