Assessment of TVT and STS Risk Score Performances in Patients Undergoing Transcatheter Aortic Valve Replacement

The Society of Thoracic Surgeons (STS) score has been used to risk stratify patients undergoing transcatheter aortic valve replacement (TAVR). The Transcatheter Valve Therapy (TVT) score was developed to predict in-hospital mortality in high/prohibitive-risk patients. Its performance in low and intermediate-risk patients is unknown. We sought to compare TVT and STS scores' ability to predict clinical outcomes in all-surgical-risk patients undergoing TAVR.

Consecutive patients undergoing TAVR from 2012-2020 within a large health care system were retrospectively reviewed and stratified by STS risk score. Predictive abilities of TVT and STS scores were compared using observed-to-expected mortality ratios (O:E) and area under the receiver operating characteristics curves (AUCs) for 30-day and 1-year mortality.

We assessed a total of 3270 patients (mean age 79 ± 9 years, 45% female), including 191 (5.8%) low-risk, 1093 (33.4%) intermediate-risk, 1584 (48.4%) high-risk, and 402 (5.8%) inoperable. Mean TVT and STS scores were 3.5% ± 2.0% and 6.1% ± 4.3%, respectively. Observed 30-day and 1-year mortality were 2.8% (92/3270; O:E TVT 0.8 ± 0.16 vs STS 0.46 ± 0.09), and 13.2% (432/3270), respectively. In the all-comers population, both TVT and STS risk scores showed poor prediction of 30-day (AUC: TVT 0.68 [0.62-0.74] vs STS 0.64 [0.58-0.70]), and 1-year (AUC: TVT 0.65 [0.62-0.58] vs STS 0.65 [0.62-0.58]) mortality. After stratifying by surgical risk, discrimination of the TVT and STS scores remained poor in all categories at 30 days and 1 year.

An updated TAVR risk score with improved predictive ability across all-surgical-risk categories should be developed based on a larger national registry.