Background: The Society of Thoracic Surgery (STS) risk score serves as an important determinant of eligibility for transcatheter aortic valve replacement (TAVR). The STS score's validity for predicting TAVR mortality, however, is incompletely understood. This study compares the STS score's discriminatory power for TAVR mortality as compared with surgical aortic valve replacement (SAVR) mortality.
Methods: A retrospective analysis of STS score and 30-day mortality for TAVR patients (n = 426) and SAVR patients (n = 297) at a single institution was performed. The performance of the STS score was evaluated from the standpoint of discriminatory power. The predictive ability of STS for 30-day mortality was detected by generation of receiver operator characteristic (ROC) curves.
Results: The STS score possesses predictive ability for 30-day SAVR mortality with an area under the ROC curve of 0.791 (95% confidence interval [CI], 0.690-0.893). The STS score also possesses predictive ability for 30-day TAVR mortality with an area under the ROC curve of 0.674 (95% CI, 0.541-0.807). When stratifying TAVR by access route, the STS score for transfemoral TAVR provides an area under the ROC curve of 0.789 (95% CI, 0.569-1.000). There is not a statistically significant difference in predictive ability between SAVR and TAVR.
Conclusion: The STS score possesses predictive value for 30-day mortality in both SAVR and TAVR. Although not designed for TAVR, the STS score may provide some insight into TAVR mortality, and therefore serves as an appropriate model for efforts to develop a TAVR-specific risk prediction instrument.