Rheumatic Tricuspid Valve Disease

Rheumatic tricuspid valve disease is chronic organic involvement of the tricuspid valve after acute rheumatic fever. It almost always accompanies rheumatic mitral disease, and often aortic disease, and produces stenosis, regurgitation or both.

Rheumatic heart disease affects about 40 million people worldwide, mostly in sub-Saharan Africa, South Asia and the Pacific. Organic tricuspid involvement occurs in roughly 10 to 15% of rheumatic heart disease, mostly as regurgitation. Clinically significant tricuspid stenosis is uncommon and occurs in under 5%.

Isolated organic tricuspid rheumatic disease is rare. Tricuspid regurgitation in rheumatic mitral disease is usually functional, from pulmonary hypertension, and the two types must be told apart because treatment differs.

Pathophysiology.

Group A streptococcal pharyngitis triggers cross-reactive immune responses against valve tissue. Repeated attacks scar the valve: leaflets thicken, commissures fuse and chords shorten, giving stenosis, or leaflets retract, giving regurgitation.

Stenosis raises right atrial pressure with atrial enlargement, atrial fibrillation and systemic venous congestion, often with relatively clear lungs. Regurgitation causes volume overload of the right atrium and ventricle with annular dilatation.

Congestive hepatopathy, protein losing enteropathy, cardiorenal syndrome and cachexia follow in advanced disease.

Fatigue, abdominal distension, ascites, peripheral oedema, hepatomegaly with pulsation, right upper quadrant pain and weight loss, alongside mitral symptoms. Signs: a giant a wave (stenosis, in sinus rhythm), prominent v waves (regurgitation), a diastolic rumble at the left lower sternal edge that increases with inspiration, a holosystolic regurgitant murmur, atrial fibrillation, and the murmurs of coexisting mitral and aortic disease.

• Echocardiography (including three dimensional): thickened, domed leaflets with restricted opening and fused commissures, shortened chords, annular size, right ventricular function (TAPSE under 17 mm abnormal), and right atrial size.
• Severe tricuspid stenosis: valve area 1.0 cm2 or less, pressure half time 190 ms or more, mean diastolic gradient 5 mmHg or more at a heart rate under 100 beats/min.
• Severe tricuspid regurgitation: vena contracta 7 mm or more, effective regurgitant orifice area 40 mm2 or more, regurgitant volume 45 mL or more, systolic flow reversal in hepatic veins. Annular diameter over 40 mm (over 21 mm/m2) indicates annular dilatation.
• ECG: tall P waves, right axis, atrial fibrillation. Chest radiograph: cardiomegaly with clear lung fields in isolated tricuspid stenosis.
• Right heart catheterisation when a gradient or pulmonary pressure is uncertain; MRI for right ventricular volume and function.
• Blood tests: full blood count, creatinine, liver tests, albumin and NT-proBNP.

Differential diagnosis.

• Functional tricuspid regurgitation, Ebstein anomaly and carcinoid heart disease.
• Infective endocarditis, right atrial myxoma or thrombus.
• Constrictive pericarditis, pacemaker lead related regurgitation and traumatic flail leaflet.

Secondary prevention of rheumatic fever (all patients).

• Benzathine benzylpenicillin 1.2 million units intramuscularly every 4 weeks (600,000 units when weight is 30 kg or less); every 3 weeks in high incidence regions or with recurrences.
• Duration: for at least 10 years after the last attack or until age 40, whichever is longer; for life when valve disease is moderate or severe or after valve surgery.
• Penicillin allergy: erythromycin 250 mg orally twice daily, or sulfadiazine 1 g orally once daily (500 mg when weight is 30 kg or less; avoid in the last trimester of pregnancy and in G6PD deficiency).
• No renal dose adjustment; monitor adherence and injection reactions, with adrenaline available for anaphylaxis.

Decongestion.

• Furosemide 40 to 120 mg orally once or twice daily, titrated to dry weight (intravenous when gut oedema limits absorption); electrolytes and creatinine within 1 week of changes.
• Spironolactone 25 to 100 mg daily (potassium under 5.0 mmol/L and eGFR over 30 mL/min/1.73 m2; check at 1 and 4 weeks).
• Sodium restriction to about 2 g daily. Avoid over diuresis, since the right ventricle depends on preload.

Atrial fibrillation.

• Anticoagulate with warfarin to INR 2.0 to 3.0 (start 5 mg daily, 2 to 3 mg in older adults; INR every 2 to 3 days, then monthly when stable). Warfarin is preferred over direct oral anticoagulants in rheumatic atrial fibrillation.
• Rate control with metoprolol succinate 25 to 200 mg daily (maximum 200 mg usual) or digoxin 125 to 250 microgram daily (62.5 to 125 microgram in older adults or renal impairment, level 0.5 to 0.9 nanogram/mL). Slower rates lengthen diastolic filling and help associated mitral stenosis.

Surgery and intervention.

• Tricuspid stenosis: indicated for severe stenosis with symptoms, or severe stenosis at the time of left sided valve surgery. Options are commissurotomy (selected pliable valves) or replacement, usually with a bioprosthesis because mechanical tricuspid valves have a high thrombosis rate. Balloon valvuloplasty seldom gives lasting results and may cause severe regurgitation.
• Tricuspid regurgitation: annuloplasty with a ring at the time of left sided surgery when regurgitation is moderate or worse, or mild with annular diameter over 40 mm. Replacement is needed when the leaflets are destroyed.
• Anticoagulation after a bioprosthesis: warfarin to INR 2.0 to 3.0 for 3 to 6 months. Mechanical valve: INR 3.0 (2.5 to 3.5) for life.
• Transcatheter tricuspid repair or replacement in selected inoperable patients (limited rheumatic data).

Monitoring. Clinical review and echocardiography yearly for moderate disease, every 6 to 12 months for severe disease or after intervention; INR monthly when stable (target 2.0 to 3.0, or 2.5 to 3.5 for a mechanical valve); creatinine, electrolytes, albumin and liver tests every 3 to 6 months; adherence to penicillin at every visit.

Referral and escalation. Refer all suspected rheumatic heart disease to a rheumatic heart disease service or cardiologist and enter into a register. Refer to a heart team for severe stenosis or regurgitation, refractory congestion, rising bilirubin or creatinine, or before pregnancy.

Special groups.

• Pregnancy: continue benzathine benzylpenicillin. Replace warfarin with low molecular weight heparin between 6 and 12 weeks of gestation, or throughout in high risk valves; avoid direct oral anticoagulants; manage in a cardio obstetric clinic.
• Children and adolescents: weight based penicillin dosing; screen siblings and schoolchildren with echocardiography in endemic areas.
• Kidney or liver impairment: adjust digoxin and diuretics, and monitor INR more often in hepatic congestion.
• Region specific: poor access to surgery and anticoagulation monitoring is common, so earlier referral and pregnancy planning are important.