Long-Term Prognostic Value of the Society of Thoracic Surgery Risk Score in Patients Undergoing Transcatheter Aortic Valve Implantation (From the OCEAN-TAVI Registry)

Abstract

The Society of Thoracic Surgeons (STS) risk model, designed to predict operative mortality after cardiac surgery, is often used for the risk assessment of patients considered for transcatheter aortic valve implantation (TAVI). We investigated the long-term prognostic value of the STS score by utilizing the data of 2588 patients undergoing TAVI from the OCEAN (Optimized CathEter vAlvular iNtervention)-TAVI Japanese multicenter registry. The patients were divided into 3 groups according to their pre-procedural STS score as follows: low-risk (STS score <4%, n = 467 [18%]), intermediate-risk (4%≤ STS score <8%, n = 1200 [46.4%]), and high-risk (8%≤ STS score, n = 921 [35.6%]). Low-risk patients were younger and were more frequently male. The prevalence of most of the comorbidities were higher in high-risk patients, while active cancer was more frequent in low-risk patients (p <0.001).The cumulative 4-year all-cause mortality rates were higher in high-risk patients (49.0%) but comparable in low-risk (22.6%) and intermediate-risk patients (28.7%) (hazard ratio [HR] for intermediate-risk versus low-risk, 1.03; 95% confidence interval [CI], 0.77 to 1.37; p = 0.85; HR for high-risk versus low-risk, 2.27; 95% CI 1.72 to 2.99; p = <0.001). Similarly, the cumulative 4-year cardiovascular mortality rates were higher in high-risk patients (20.5%) but comparable in low-risk (9.9%) and intermediate-risk patients (10.3%) (HR for intermediate-risk versus low-risk, 1.10; 95% CI, 0.68 to 1.77; p = 0.69; HR for high-risk versus low-risk, 2.33; 95% CI 1.48 to 3.67; p = <0.001). After adjustment for several confounders, STS score ≥8% was independently associated with increased long-term mortality (HR, 1.35; 95% CI, 1.08 to 1.68). In conclusion, the risk stratification according to STS score demonstrated an increased risk of long-term mortality after TAVI in high-risk patients, albeit with comparable risks in intermediate- and low-risk patients.