Functional Tricuspid Regurgitation in Patients With Chronic Mitral Regurgitation: An Evidence-Based Narrative Review.

Chronic mitral regurgitation leads to a series of downstream pathologic changes, including pulmonary hypertension, right ventricular dilation, tricuspid leaflet tethering, and tricuspid annular dilation, which can result in functional tricuspid regurgitation (FTR). The five-year survival rate for patients with severe FTR is reported to be as low as 34%. While FTR was often left uncorrected during left-heart valvular surgery, under the assumption that correction of the left-sided lesion would reverse the right-heart changes that cause FTR, recent data largely have supported concomitant tricuspid valve repair at the time of mitral surgery. In this review, the authors discuss the potentially irreversible nature of the changes leading to FTR, the likelihood of progression of FTR after mitral surgery, and the evidence for and against concomitant tricuspid valve repair at the time of mitral valve intervention. Lastly, this narrative review also examines advances in transcatheter therapies for the tricuspid valve and the evidence behind concomitant transcatheter tricuspid repair at the time of transcatheter mitral repair.