Tricuspid valve disease

Tricuspid valve disease

The majority of serious heart valve problems affect the mitral and aortic valves. Tricuspid regurgitation (TR) is more common than tricuspid stenosis and usually develops in association with pulmonary hypertension in patients with mitral stenosis or mitral regurgitation.

Tricuspid stenosis¹

Tricuspid stenosis is rare, occurring in less than 1% of the population. Tricuspid stenosis is most often rheumatic in origin² .

Tricuspid stenosis is often combined with tricuspid regurgitation and most frequently of rheumatic origin. It is therefore usually associated with left-sided valve lesions, particularly mitral stenosis. Other causes are rare, including congenital, carcinoid syndrome, Whipple’s disease, endocarditis, and large right atrial tumour.

Valve leaflets become thickened and undergo sclerosis with narrowing of the opening area of the valve. This leads to enlargement of the right atrium and reduced flow into the ventricle. Blood flow into the pulmonary circulation is impaired and is accompanied by peripheral oedema and hepatomegaly.

Tricuspid valve disease symptoms

See also the separate Heart Auscultation and Heart Murmurs in Children articles.

Detection requires careful evaluation, as it is almost always associated with left-sided valve lesions that dominate the presentation. Clinical signs are often masked by associated valve lesions, especially mitral stenosis.

• History of rheumatic fever.

• Low output symptoms of fatigue, anorexia, wasting, peripheral cyanosis and cold skin.

• Usually those of accompanying left-sided rheumatic valve lesions.

• Right hypochondrial discomfort from liver distension, hepatic pulsation, ascites and peripheral oedema, which are severe compared to the degree of dyspnoea.

• In sinus rhythm - an 'a' wave in the jugular venous pulse.

• A low rumbling diastolic murmur along the left sternal border, which increases with inspiration.

• Tricuspid regurgitation is often also present, causing a pansystolic murmur in a similar location.

• The first heart sound may be split widely and the second heart sound may be single (inaudible closure of the pulmonary valve).

Investigations

• ECG may show evidence of right atrial hypertrophy with tall peaked P waves; arrhythmias (eg, atrial fibrillation, atrial flutter) occur frequently.

• CXR may show a dilated right atrium without an enlarged pulmonary-artery segment.

• Echocardiography: to detect and quantify tricuspid stenosis and for assessment of the dimensions of cardiac chambers, determination of right ventricular and pulmonary pressures and detection of associated other heart valve abnormalities³ .

• Cardiac catheterisation: may be required prior to surgery to assess for possible coronary artery disease. Right heart catheterisation can help to determine the severity of the stenosis and associated congenital defects. Assessment of aortic and mitral valves via left heart catheterisation is useful in patients with rheumatic disease.

Echocardiography provides the most useful information. Tricuspid stenosis is often overlooked and requires careful evaluation. Echocardiographic evaluation of valve anatomy and subvalvular apparatus is important to assess valve reparability.

Tricuspid valve disease treatment and management

Medical therapy
Diuretics are useful in the presence of heart failure symptoms but are of limited long-term efficacy.

Surgery
Intervention on the tricuspid valve is usually performed concomitantly during procedures for left-sided valve disease in patients who are symptomatic despite medical therapy.

Although the lack of pliable leaflet tissue is a main limitation for valve repair, the choice between repair and replacement depends on anatomy and surgical expertise.

Because of satisfactory long-term durability, biological prostheses are usually preferred over mechanical valves, which have a high risk of thrombosis.

Percutaneous tricuspid balloon valvuloplasty has been performed in a limited number of cases, either alone or in combination with percutaneous mitral commissurotomy. It frequently induces significant regurgitation and long-term results are lacking. It can be considered in rare cases with anatomically suitable valves, when tricuspid stenosis is isolated or additional mitral stenosis can also be treated surgically.

Prognosis

• Prognosis is generally good but dependent on the prognosis of the underlying disease, associated other heart abnormalities and associated arrhythmias.

Tricuspid regurgitation¹

TR can be divided into primary and secondary⁴ :

• Primary TR is relatively rare. It is caused by a lesion of the tricuspid valve due to congenital or acquired disease processes that affect the leaflets or chordal structures, or both.

• Secondary TR is more common and is secondary to other diseases such as left-side heart diseases, pulmonary hypertension, right ventricle dilation, and dysfunction from any cause, without any intrinsic lesion of the tricuspid valve.

Moderate or severe tricuspid regurgitation occurs in 0.55% of the general population and its prevalence increases with age, affecting about 4% of the patients aged 75 years or more.

Aetiology is secondary in over 90% of cases, due to pressure and/or volume overload right ventricular dilatation or enlarged right atrium and tricuspid annulus due to chronic atrial fibrillation.

Secondary tricuspid regurgitation is associated with left-sided valvular or myocardial dysfunction in most cases, whereas it is isolated in 8.1% of patients and independently related to mortality. Secondary tricuspid regurgitation may also develop late after left-sided valve surgery.

The causes of primary tricuspid regurgitation include infective endocarditis (especially in intravenous drug addicts, rheumatic heart disease, carcinoid syndrome, myxomatous disease, endomyocardial fibrosis, congenital valve dysplasia (eg, Ebstein’s anomaly), thoracic trauma, and iatrogenic valve damage.

Atrial fibrillation induces annular remodelling even in the absence of left-heart disease.
Cardiac implantable electronic device-lead implantation leads to progressive tricuspid regurgitation in 20-30% of the patients.

In patients with heart failure and reduced left ventricular ejection fraction, secondary tricuspid regurgitation is a very frequent finding and is an independent predictor of clinical outcomes.

Tricuspid regurgitation symptoms

See also the separate Heart Auscultation and Heart Murmurs in Children articles.

Predominant tricuspid regurgitation symptoms are those of other associated valve diseases. Even severe TR may be well tolerated for a long period of time. Clinical signs of right heart failure are useful in evaluating the severity of TR .

• It is often asymptomatic in the absence of pulmonary hypertension.

• Development of pulmonary hypertension leads to reduction of cardiac output and features of right heart failure with dyspnoea, fatigue, cyanosis, cold skin, oedema and discomfort in the right hypochondrium.

• Jugular venous pressure is elevated with a prominent systolic 'v' wave.

• Right ventricular impulse is hyperdynamic and may be thrusting in quality.

• Systolic pulsations of an enlarged, tender liver.

• Ascites and oedema.

• Heart sounds and murmurs:
  

  • High-pitched pansystolic murmur, most prominent in the fourth intercostal space in the left parasternal region. In the absence of pulmonary hypertension, the murmur is usually low-intensity and early systolic.

  • The murmur is accentuated during inspiration, with exercise, with legs raised, and with direct liver compression.

  • The pulmonary component of the second heart sound becomes louder in the presence of pulmonary hypertension.

  • Tricuspid valve prolapse may present with a midsystolic click and a late systolic murmur, most prominent at the lower left sternal border.

Investigations

• ECG: findings are usually nonspecific; they may show right atrial hypertrophy (tall peaked 'p' waves), incomplete right bundle-branch block, Q waves in lead V1, and atrial fibrillation.

• CXR: shows marked cardiomegaly with right heart enlargement, and pleural effusions. Ascites with diaphragmatic elevation may be present. Pulmonary arterial and venous hypertension are common.

• Echocardiography: to detect and quantify tricuspid regurgitation and for assessment of the dimensions of cardiac chambers, determination of right ventricular and pulmonary pressures and detection of other associated heart valve abnormalities³ .

• When available, cardiac magnetic resonance (CMR) is the preferred method for evaluating right ventricular size and function.

• Cardiac catheterisation: may be required prior to surgery to assess for possible coronary artery disease and help determine the severity of the regurgitation and associated congenital defects.

Tricuspid regurgitation should be assessed first by echocardiography. In primary tricuspid regurgitation, specific abnormalities of the valve can be identified. In secondary tricuspid regurgitation, annular dilatation, along with right ventricular and right atrium dimensions, as well as right ventricular function should be measured in view of their prognostic relevance.

Estimation of pulmonary pressures using Doppler gradient may be impossible or might underestimate the severity of pulmonary hypertension in the presence of severe tricuspid regurgitation, justifying cardiac catheterisation to evaluate pulmonary vascular resistances.

Tricuspid regurgitation treatment and management⁵

The benefit of surgical correction of isolated secondary tricuspid regurgitation compared to medical treatment is not well established. However, in selected patients, surgery can be performed safely with good long-term survival. It should therefore be considered early in selected symptomatic patients appropriate for surgery, as well as in those with no or mild symptoms, right ventricular dilatation and severe tricuspid regurgitation.

Medical therapy

• Diuretics are useful in the presence of right heart failure. To counterbalance the activation of the renin-angiotensin-aldosterone system associated with hepatic congestion, the addition of an aldosterone antagonist may be considered.

• Treatment of pulmonary hypertension may be indicated.

• Rhythm control may help to decrease tricuspid regurgitation and contain annular dilatation in patients with chronic atrial fibrillation.

Indications for surgical intervention
Tricuspid valve repair should be performed during left-sided surgery in patients with secondary tricuspid regurgitation.

Severe tricuspid regurgitation is associated with impaired survival and worsening heart failure. Appropriate timing of intervention is essential to avoid irreversible right ventricular damage and organ failure with subsequent increased surgical risk.

Surgery is recommended in symptomatic patients with severe primary tricuspid regurgitation. In selected asymptomatic or mildly symptomatic patients who are appropriate for surgery, an intervention should also be considered if there is right ventricular dilatation or declining right ventricular function.

Surgery
Whenever possible, annuloplasty with prosthetic rings is preferable to valve replacement, which should only be considered when the tricuspid valve leaflets are tethered and the annulus severely dilated.

Re-operation on the tricuspid valve in new-onset or worsening secondary tricuspid regurgitation after left-sided surgery carries a high risk. To improve prognosis, treatment of severe tricuspid regurgitation should be considered even in asymptomatic patients if there are signs of right ventricular dilatation or decline in right ventricular function (after exclusion of left-sided valve dysfunction, severe right ventricular or left ventricular dysfunction and severe pulmonary vascular disease/hypertension).

Transcatheter tricuspid valve intervention (TTVI) is under clinical development. TTVI may be considered at experienced Heart Valve Centres in symptomatic, inoperable, anatomically eligible patients in whom symptomatic or prognostic improvement can be expected.

For adults, the National Institute for Health and Care Excellence (NICE) recommends⁶ :

• Consider surgical tricuspid valve repair at the time of mitral valve surgery when tricuspid regurgitation is moderate or severe.

• Consider surgical tricuspid valve repair at the time of aortic valve surgery when tricuspid regurgitation is severe.

Prognosis

• Severe TR has a poor prognosis, even if it may be well tolerated functionally for years.

• Prolonged volume overload may result in ventricular dysfunction and irreversible myocardial damage.

• Flail tricuspid valve (classically associated with severe TR) is associated with decreased survival and increased risk of heart failure.

• TR may persist even after successful correction of left-sided lesions.

• Pulmonary hypertension, increased right ventricular pressure and dimension, reduced right ventricular function, atrial fibrillation, pacemaker leads and the severity of tricuspid valve deformation are important risk factors for persistence or late worsening of TR.

Tricuspid atresia⁷

Venous blood returning to the right atrium can only exit via an intra-atrial communication. Other cardiovascular anomalies may co-exist with tricuspid atresia - eg, transposition of the great vessels.

Tricuspid atresia symptoms

• Tricuspid atresia is usually detected in infancy with cyanosis, heart failure and growth restriction.

• Raised jugular venous pressure.

• The left ventricular impulse is prominent because of volume overload. The apical impulse is displaced to the left of the mid-clavicular line.

• The liver may be large and pulsatile.

• There is usually a single first heart sound that may be increased in intensity. The second heart sound may be single or normally split.

• Cardiac murmurs are often present:
  

  • A pansystolic murmur, which may signify blood flow through the ventricular septal defect.

  • Systemic-to-pulmonary arterial collaterals or arterial-to-pulmonary arterial anastomoses surgically created to improve pulmonary blood flow, which may cause a continuous murmur.

  • A murmur indicating mitral regurgitation, which may be present.

Investigations

• FBC may show polycythaemia.

• Blood gases may show hypoxaemia and acidosis.

• CXR: cardiomegaly is usually present, with a prominent right heart border (enlargement of the right atrium). Pulmonary vascular markings are usually diminished (but may be increased when pulmonary flow is not obstructed).

• Other investigations include ECG, echocardiography and cardiac catheterisation.

Tricuspid atresia treatment and management

• Infants with obstructed pulmonary blood flow and severe hypoxaemia require urgent prostaglandin E infusions in order to maintain patency of the ductus arteriosus.

• Other non-surgical management includes oxygen therapy, prevention of bacterial endocarditis and management of heart failure.

• Most patients with tricuspid atresia require some form of surgical treatment during the first year of life, usually involving a palliative shunt procedure.

• Fontan's operation involves the formation of a right atrial-to-pulmonary artery connection or an extracardiac vena cava-to-pulmonary artery anastomosis⁸ .

Complications

• Paradoxical emboli, stroke, brain abscess.

• Polycythaemia.

• Progressive cardiac dilatation.

• Ventricular dysfunction.

• Mitral valve insufficiency.

• Arrhythmias.

Prognosis

The prognosis will depend on associated cardiac abnormalities. The perioperative mortality of the Fontan procedure is below 2% .