Introduction
The presence of some degree of tricuspid regurgitation (TR) can be considered the most common valvular heart disease, affecting 65-85% of the population1. If considered only significant TR (moderate or severe), the condition is estimated to affect up to 1.6 million individuals in the United States2, with secondary or functional tricuspid regurgitation (FTR) being responsible for almost 90% of the cases3.
Despite this prevalence, TR was during many years a forgotten and underappreciated disease4,5. One of the reasons behind TR undertreatment was the concept, postulated by Braunwald in 19676 that functional tricuspid regurgitation (FTR) would improve or disappear once the primary left-sided problem was treated. Another reason was the high surgical mortality rate associated with isolated tricuspid valve (TV) intervention, which, unfortunately, remains at least partially correct, since TR carries an impactful surgical mortality (8.8% – 9.7%)7. However, such high mortality is in part biased by the advanced stage that patients are referred to surgery, with severe right ventricle dysfunction and end-organ damage8.
Additionally, several publications have demonstrated that up to 74% of patients submitted to a successful mitral valve repair will exhibit significant tricuspid regurgitation (TR) over more than 3-year follow-up9, and one half will progress by more than two grades in a mean follow-up of 4.8 years10. It is also remarkable that, while isolated TV surgery due to residual TR after mitral valve (MV) intervention is associated with high mortality and poor outcomes11,7, concomitant TV repair does not increase the operative mortality10,12.
Based on these arguments and on the fact that FTR is associated with biventricular dysfunction, poor quality of life and, ultimately, death13-15, a more aggressive TR surgical approach was suggested. Hence, the concept of treating TR based on tricuspid annulus diameter rather than TR severity was raised10.