Outcomes of Isolated Tricuspid Valve Surgery: A Society of Thoracic Surgeons Analysis and Risk Model

BACKGROUND To provide patients and surgeons with clinically relevant information, the Society of Thoracic Surgeons Adult Cardiac Surgery Database (STS-ACSD) was queried to develop a risk model for isolated tricuspid valve (TV) operations. METHODS All patients in the STS-ACSD undergoing isolated TV repair or replacement (N=13,587; age 48.3±18.4 years) were identified (7/2017-6/2023). Multivariable logistic regression accounting for TV replacement versus repair was used to model eight operative outcomes: mortality, morbidity and/or mortality, stroke, renal failure, reoperation, prolonged ventilation, short and prolonged hospital stay. Model discrimination (C-statistic) and calibration were assessed using 9-fold cross-validation. RESULTS The isolated TV study population included 41.1% repairs (N=5,583; age 52.6±18.1 years) and 58.9% replacements (N=8,004; age 45.3±18.0 years). Overall predicted risk of operative mortality was 5.6%, similar in repairs and replacements (5.5% and 5.7%, respectively); as was the predicted risk of composite morbidity and mortality (28.2% and 26.8%). Replacements were generally younger patients with a higher endocarditis prevalence than repairs (45.7% vs. 21.1%). The model yielded a C-statistic of 0.81 for mortality and 0.76 for the composite of morbidity and mortality, with excellent observed-to-expected calibration that was comparable in all sub-cohorts and predicted risk decile groups. CONCLUSIONS A new STS risk model has been developed for isolated TV surgery. The current mortality of isolated TV operations is lower than previously observed. This risk prediction model and these contemporary outcomes provide a new benchmark for current and future isolated TV interventions.