ObjectiveTo evaluate the early and mid-term mortality rates of isolated tricuspid valve replacement (iTVR) and concomitant tricuspid valve replacement (cTVR), and to assess associated risk factors. MethodsPatients with tricuspid regurgitation who underwent TVR at Nanjing First Hospital between June 2012 and May 2021 were retrospectively enrolled. Early and mid-term outcomes were compared between iTVR and cTVR patients. The predictive performance of the European System for Cardiac Operative Risk EvaluationⅡ (EuroSCOREⅡ) for perioperative mortality was also evaluated. ResultsA total of 67 patients were included, comprising 23 (34%) males with a mean age of (52±13) years. Atrial fibrillation was the most common comorbidity (35/67, 52%). Among these patients, 40 underwent iTVR and 27 underwent cTVR. The perioperative mortality rate was 18%, with causes including low cardiac output syndrome (LCOS), bleeding, multiple organ failure, and severe sepsis. Compared to survivors, non-survivors were older, had worse cardiac function, larger left atrial diameters, higher EuroSCOREⅡ values, longer cardiopulmonary bypass (CPB) time and ICU stays, and higher complication rates (P<0.05). EuroSCOREⅡ was significantly associated with perioperative mortality [OR=1.274, 95%CI (1.065, 1.740), P=0.049]. The median follow-up duration was 32.9 (18.9, 73.2) months, during which 5 patients died. The survival rates at 6 months, 1 year, 3 years, and 5 years postoperatively were 98.1%, 97.4%, 82.6%, and 77.8%, respectively. Compared to cTVR, iTVR demonstrated shorter CPB and aortic cross-clamp time, lower perioperative mortality, and reduced incidence of LCOS. EuroSCOREⅡ showed good predictive performance for perioperative mortality in both iTVR and cTVR (area under the receiver operating characteristic curve: 0.982 vs. 0.684). During follow-up, there was no statistical difference in survival rates between iTVR and cTVR patients (P=0.489). ConclusionCompared to cTVR, iTVR is associated with lower perioperative mortality and LCOS incidence, while mid-term survival rates are similar. EuroSCOREⅡ effectively predicts perioperative mortality risk for TVR, with superior predictive performance observed in iTVR.