Linda W. Van Laake

Background Soluble suppression of tumorigenicity‐2 (sST2) predicts mortality in patients with heart failure. The predictive value of sST2 in patients with a left ventricular assist device remains unknown. Therefore, we studied the relationship between sST2 and outcome after left ventricular assist device implantation. Methods and Results sST2 levels of patients with a left ventricular assist device implanted between January 2015 and December 2022 were included in this observational study. The median follow‐up was 25 months, during which 1573 postoperative sST2 levels were measured in 199 patients, with a median of 29 ng/mL. Survival of patients with normal and elevated preoperative levels was compared using Kaplan‐Meier analysis, which did not differ significantly ( P =0.22) between both groups. The relationship between postoperative sST2, survival, and right heart failure was evaluated using a joint model, which showed a significant relationship between the absolute sST2 level and mortality, with a hazard ratio (HR) of 1.20 (95% CI, 1.10–1.130; P <0.01) and an HR of 1.22 (95% CI, 1.07–1.39; P =0.01) for right heart failure, both per 10‐unit sST2 increase. The sST2 instantaneous change was not predictive for survival or right heart failure ( P =0.99 and P =0.94, respectively). Multivariate joint model analysis showed a significant relationship between sST2 with mortality adjusted for NT‐proBNP (N‐terminal pro‐B‐type natriuretic peptide), with an HR of 1.19 (95% CI, 1.00–1.42; P =0.05), whereas the HR of right heart failure was not significant (1.22 [95% CI, 0.94–1.59]; P =0.14), both per 10‐unit sST2 increase. Conclusions Time‐dependent postoperative sST2 predicts all‐cause mortality after left ventricular assist device implantation after adjustment for NT‐proBNP. Future research is warranted into possible target interventions and the optimal monitoring frequency.