The better substitute for tricuspid valve replacement in patients with severe isolated tricuspid regurgitation Introduction Primary tricuspid valve regurgitation is rarely observed in adults and is known to result from congenital heart disease, rheumatic heart disease, myxomatous valve disease, infective endocarditis, carcinoid syndrome, and/or infiltrative valvulopathy (1). Tricuspid valve repair is the first option for patients with primary or secondary tricuspid regurgitation. However, valve replacement, instead of repair, may be better for those with severe structural valve dysfunction. In patients with isolated tricuspid valve regurgitation, tricuspid valve replacement (TVR) has been associated with a considerable reported risk of mortality and a high incidence of prosthesis-related complications, which could lead to a high number of reoperations (2). With regard to prosthesis, the choice between mechanical and bioprosthetic valves remains controversial. Furthermore, only a few studies have assessed the clinical outcomes of patients with primary tricuspid valve regurgitation after isolated TVR. The aim of the present study was to evaluate the long-term outcomes in patients undergoing first-time TVR with a mechanical or bioprosthetic valve for severe isolated tricuspid valve regurgitation. Methods Patients A total of 98 patients with primary tricuspid valve regurgitation underwent first-time TVR at the West China Hospital in China between January 2010 and March 2017. The prosthesis used was determined by the attending physician after considering age, symptoms, other comorbidities, and particularly the will of the patients. The present study was Objective: The ideal alternative for tricuspid valve replacement (TVR) in patients with severe isolated tricuspid regurgitation remains unclear. The aim of the present study was to retrospectively investigate the outcomes of using bioprosthetic and mechanical valves at the tricuspid position. Methods: A total of 98 consecutive patients without left-side cardiac disease or history of heart surgery who underwent first-time TVR between January 2010 and March 2017 at the West China Hospital, China were included in the study. Patient data, including all-cause death and need for tricuspid valve reoperation as the main end points, were retrospectively evaluated. Results: A total of 76 patients were enrolled into the study. The mean follow-up period was 43.3±21.9 (10-87) months. The mean age of the patients was 45.7±13.4 years. The study comprised 32.9% of male patients. During the follow-up period, 4, 3, 12, and 3 cases of death, reoperation, prosthesis dysfunctions, and prosthesis-related thrombosis were noted, respectively. Biological and mechanical valves were used in 56.6% and 43.4% of the patients, respectively. However, there was no significant difference between mechanical and biological valves with respect to echocardiographic date and survival, reoperation, prosthetic valve dysfunction, and thromboembolism rate. Conclusion: TVR is not a very high-risk procedure in pa...