ST2 predicts survival in patients undergoing transcatheter aortic valve implantation

Objective: To assess soluble suppression of tumorigenicity 2 (sST2) serum concentrations and predict mortality in patients undergoing transcatheter aortic valve implantation (TAVI).

Methods: We prospectively enrolled 74 patients with severe aortic stenosis (AS) who underwent TAVI and matched them to patients without aortic valve disease (n=74). AS patients underwent comprehensive echocardiographic and cardiac magnetic resonance imaging and laboratory examinations. sST2 levels were determined by enzyme-linked immunosorbent assay (ELISA), their association with post procedural mortality was investigated using logistic and Cox regression analyses, and the prognostic performance compared to established risk scores.

Results: AS patients had substantially higher sST2 levels than controls (39.5 vs. 17.8ng/mL, p<0.001). sST2 significantly correlated with left and right atrial sizes (r=0.25, p=0.033 and r=0.38, p=0.001). At one and two years, 10 (13.9%) and 18 (25%) patients had died, respectively. sST2 significantly predicted survival in uni- and multivariate Cox regression analyses in our cohort (p=0.005 and p=0.025). sST2 also predicted major adverse cardiovascular events (MACE, p=0.046). Adding sST2 to the established STS score improved prediction of two-year mortality in our cohort (ΔAUC=0.108; 95% CI -0.066-0.281; continuous NRI=0.778; 95% CI: 0.277-1.278 and IDI=0.141; 95% CI: 0.031-0.251), and a model containing both sST2 and the STS score had a negative predictive value of 96.1% and 86.3% regarding one and two-year mortality, respectively.

Conclusions: sST2 is elevated in AS patients and a prognostic marker of survival after TAVI. Implementation of this marker in routine pre-TAVI workup may improve risk prediction and patient selection.