Prognostic value of ST2 in myocardial infarction.

Introduction: Soluble Suppression of Tumorigenicity 2 (ST2) is a biomarker of myocardial fibrosis increasingly recognized as a predictor of morbidity and mortality in heart failure. Its role in the prognosis after a myocardial infarction has not been validated to date.

Aim: To evaluate the prognostic value of ST2 for in-hospital morbidity and mortality after myocardial infarction.

Methods: We conducted a longitudinal prospective study including 74 patients admitted for an acute uncomplicated cardiac myocardial infarction at Habib Thameur hospital between April and October 2016. ST2 blood samples were drawn until 72 hours post admission .The primary endpoint was the occurrence of a major cardiovascular event during hospitalization.

Results: Patients' mean age was 61.28 ± 13 years-old with a sex ratio of 1.8. The reason for admission was acute coronary syndrome with persistent ST segment elevation in 54% of cases and non-ST segment elevation acute myocardial infarction in 46% of cases. The ST2 assay was positive in 78% of cases with a mean value of 122.43 ± 95.72 ng/ ml. Left ventricular dysfunction was observed in 47% of cases. Fifteen per cent of the patients had a 3 vessel-disease, 24% a 2 vessel-disease and 34% a 1 vessel-disease. Twenty-six percent had at least one major cardiovascular event. In-hospital mortality was 10%. In multivariate analysis, ST2 was an independent factor associated with the occurrence of major cardiovascular events (RR = 2, p = 0.04). The cutoff value of ST2 of 35 ng/ml had a sensitivity of 95%, a specificity of 30% (AUC = 0.672, CI 0.546-0.798, p = 0.024), a negative predictive value of 100% and a positive value of 33%. A significant correlation was found between ST2 and troponin, blood glucose on admission, CRP and left ventricular ejection fraction (respectively: r = 0.398, p <0.0001, r = 0.281, p = 0.015, r = 0.245, p = 0.039, r = -0.401, p <0.0001).

Conclusion: The measurement of ST2 after a myocardial infarction constitutes a new prognostic indicator of in-hospital morbidity and mortality.