BackgroundIn patients undergoing mitral valve surgery, optimal management of less-than-severe concomitant tricuspid valve regurgitation (TR) is unclear, as there are few long-term data. This study examines progression of TR, patient survival, and reoperations in patients undergoing mitral valve surgery. MethodsThere were 1588 patients who underwent degenerative mitral valve surgery and had pre- and postoperative echocardiograms for assessment of TR severity and tricuspid annulus diameter. Analysis used repeated-measures ordinal regression to model the longitudinal trends in TR grade and proportional hazards regression for long-term survival and reoperation outcomes. ResultsConcomitant tricuspid valve (TV) surgery was performed in 235 (14.8%) patients. In response to surgery, TR grades improved more in patients with concomitant TV intervention regardless of the severity of preoperative TR, and these early trends were sustained over long-term follow-up. Risk of progression to severe TR was not influenced by tricuspid annulus diameter (P = .226). After we adjusted for underlying health characteristics, survival following mitral valve surgery was similar in patients with and without TV intervention. Late TV reoperation was observed in 22 patients (5-year cumulative risk 1.5%), but among these, only 6 patients had severe TR as the primary indication for reoperation; preoperative TR grade and initial concomitant TV surgery were not associated with incidence of reoperation. ConclusionsConcomitant TV surgery for moderate TR reduces progression of TR but did not influence survival or incidence of reoperation. Among patients with less-than-severe preoperative TR, tricuspid annular diameter was not associated with progression to severe TR.