Soluble suppression of tumorigenicity-2 (sST2) predicts mortality and right heart failure in LVAD patients

Background Soluble suppression of tumorigenicity-2 (sST2) predicts mortality in heart failure patients. The predictive value of sST2 in left ventricular assist device (LVAD) patients remains unknown. Therefore, we studied the relationship between sST2 and outcome after LVAD implantation. Methods Patients implanted between January 2015 and December 2022 were included. Survival of patients with normal and elevated pre-operative sST2 levels was compared using Kaplan-Meier analysis. The relationship between post-operative sST2, survival and right heart failure (RHF) was evaluated using a Joint Model (JM). Multivariate JM analysis adjusted for serially measured NT-proBNP was performed. Results The median follow-up was 25 months, during which 1573 post-operative sST2 levels were measured in 199 patients, with a median of 29 ng/ml. Survival in patients with normal or elevated pre-operative sST2 levels (n=86) did not differ significantly (p=0.22). Time-dependent post-operative sST2 levels were significantly associated with mortality, with a hazard ratio (HR) of 1.20 (95% CI: 1.10-1.30, p<0.01) and a HR of 1.22 (95% CI: 1.07-1.39, p=0.01) for RHF, both per 10 unit sST2 increase. The sST2 instantaneous change was not predictive for survival or RHF (p=0.99, p=0.94 respectively). Multivariate JM analysis showed a significant relationship between sST2 with mortality adjusted for NT-proBNP with HR 1.19 (95% CI: 1.00-1.42, p=0.05), while the HR of RHF was not significant (1.22, 95% CI: 0.94-1.59, p=0.14), both per 10 unit sST2 increase. Conclusion Time-dependent post-operative sST2 predicts all-cause mortality after LVAD implantation independently of NT-proBNP. Future research is warranted into possible target interventions and the optimal monitoring frequency.