Prognostic Predictors of Tricuspid Regurgitation Worsening after Mitral Regurgitation Surgery with Mild Tricuspid Regurgitation.

We aimed to investigate the prevalence and predictors of postoperative tricuspid regurgitation (TR) worsening in patients with mitral regurgitation (MR) and concomitant ≤mild TR. A total of 620 patients underwent surgery for MR from 2013 to 2017. Of these, 260 had ≤mild preoperative TR and no concomitant tricuspid valve surgery and were enrolled in this single-center retrospective study. The primary endpoint was postoperative worsening of ≥moderate TR. The primary endpoint occurred in 28 of 260 patients (11%) during the follow-up period [median: 4.1 years (interquartile range: 2.9-6.1 years)]. In the multivariable analysis, age, female sex, and left atrial volume index (LAVI) were significant predictors of the primary outcome during intermediate-term follow-up (age: hazard ratio [HR] 1.05 per 1-year increment, 95% confidence interval [CI] 1.02-1.10, P = 0.003; female sex: HR 3.53, 95% CI 1.61-7.72, P = 0.002; LAVI: HR 1.17 per 10-mL/m increment, 95% CI 1.07-1.26, P < 0.001). The optimal LAVI cut-off value for predicting postoperative TR worsening was 79 mL/m (area under the curve: 0.69). A high LAVI (>79 mL/m²) was significantly associated with a low rate of freedom from postoperative TR worsening compared with a low LAVI (≤79 mL/m²) (82.6% vs 93.9% at 5 years, respectively; log-rank P = 0.008). In patients with ≤mild preoperative TR and no concomitant tricuspid surgery, the rate of postoperative TR worsening was 11% during intermediate-term follow-up. LA enlargement in patients with MR and ≤mild preoperative TR was significantly associated with postoperative TR worsening.