Background: Soluble ST2 (sST2) is an interleukin-33 receptor. sST2 was found to be an independent prognostic factor in patients with myocardial infarction, sepsis and heart failure.
Objectives: To assess sST2 levels in patients with cardiogenic shock (CS) and septic shock (SS), and to evaluate the prognostic value of sST2 for short-term mortality.
Methods: The present prospective observational study evaluated 32 patients with CS, 17 patients with SS and 61 patients with ST segment elevation myocardial infarction (STEMI )(control group). Samples of serum were collected eight times and the follow-up time was three months.
Results: sST2 levels were elevated from admission in SS patients relative to patients with CS and STEMI, who exhibited peak sST2 levels 24 h after admission. On admission, CS patients had a median (5th percentile; 95th percentile) sST2 level of 62.5 pg/mL (8.3 pg/mL; 315.8 pg/mL) and SS patients had a median sST2 level of 216.4 pg/mL (46.8 pg/mL; 364.4 pg/mL). ROC analysis found sST2 to be a biomarker that could distinguish between CS and SS at admission (area under the curve [AUC] 0.813; P<0.01) with a cut-off value of 210.4 pg/mL. Patients with STEMI had significantly lower sST2 levels at admission (20.3 pg/mL (4.2 pg/mL; 339.8 pg/mL) compared with CS patients. The AUC of the ROC analysis was 0.671 (P=0.007) for the detection of CS in patients with STEMI. Only a weak correlation was observed between sST2 and B-type natriuretic peptide (r=0.376, P=0.05) and sST2 and N-terminal pro-B-type natriuretic peptide (r=0.496, P=0.019). No statistically significant differences were observed in sST2 levels in patients with CS and SS relative to three-month mortality.
Conclusion: Levels of sST2 at admission are significantly higher in patients with SS compared with CS. sST2 could be a diagnostic marker to distinguish SS and CS as well as CS and STEMI at the time of admission. Levels of sST2 are related to levels of natriuretic peptides in CS but not in SS. sST2 levels are not a suitable prognostic marker for patients with CS and SS.
Keywords: Cardiogenic shock; Circulating levels; ST2; Septic shock.