Tricuspid regurgitation: contemporary management of a neglected valvular lesion

Abstract

Right-sided cardiac valvular disease has traditionally been considered less clinically important than mitral or aortic valve pathology. However, detectable tricuspid regurgitation (TR) is common and recent data suggest that significant TR can lead to functional impairment and reduced survival, particularly in patients with concomitant left-sided valvular disease. The tricuspid valve is a complex anatomical structure and advances in three dimensional echocardiography and cardiac MRI have contributed to a greater understanding of tricuspid valve pathology. These imaging techniques are invaluable in determining the aetiology and severity of TR, and provide an assessment of right ventricular function and pulmonary artery pressure. TR is more prevalent in women and those with a history of myocardial infarction and heart failure. It also occurs in about 10% of patients with rheumatic heart disease. Chronic severe TR may have a prolonged clinical course culminating in the development of fatigue and poor exercise tolerance due to a reduced cardiac output. Approximately 90% of cases of TR are secondary to either pulmonary hypertension or intrinsic right ventricular pathology and about 10% are due to primary tricuspid valve disease. Primary causes such as Ebstein's anomaly, rheumatic disease, myxomatous changes, carcinoid syndrome, endomyocardial fibrosis, and degenerative disease have characteristic morphological features readily identifiable by echocardiography. Ascertaining an accurate right ventricular systolic pressure is important in separating primary from secondary causes as significant TR with a pressure <40 mm Hg implies intrinsic valve disease. Cardiac MRI may be indicated in those with inadequate echocardiographic images and is also the gold standard for the evaluation of right ventricular function and morphology. The assessment of leaflet morphology, annular dimensions, and pulmonary artery pressure are particularly important for determining subsequent management. Along with appropriate treatment of the underlying cause of TR and pulmonary hypertension, management guidelines indicate a move towards more aggressive treatment of TR. In those undergoing left-sided valve surgery, tricuspid valve repair is universally recommended in the presence of severe coexistent TR; in those with isolated severe TR, surgery is recommended in the presence of symptoms or progressive right ventricular dilatation or dysfunction.