The Association of Thyroid Hormones With Cardiogenic Shock and Prognosis in Patients with ST Segment Elevation Myocardial Infarction (STEMI) Treated with Primary PCI

Background: Cardiogenic shock (CS) is the leading cause of the death in patients with ST elevation myocardial infarction (STEMI). Thyroid dysfunction is related to prognosis of patients with myocardial infarction. Hence, the aim of this study is to explore the relationship between thyroid hormones (free triiodothyronine [FT3] and free thyroxine [FT4]) and CS. Methods: A total of 1270 patients with STEMI treated with percutaneous coronary intervention (PCI) were consecutively enrolled in our study. Patients were classified into two groups according to with or without CS during hospitalization. Stepwise multivariate logistic analysis was conducted to investigate the association of thyroid hormones and CS. Restricted cubic spline method was employed to further explore the relationship between CS and thyroid hormones. Results: Patients who developed CS (n=103) had lower FT3 and higher FT4 upon admission. The stepwise logistic analysis showed both FT3 (P=0.038) and FT4 (P=0.024) were independently related to CS. Restricted cubic splines indicated that lower FT3 (<2.25 pg/ml) or higher FT4 (>1.25 ng/dl) were correlated with higher prevalence of CS. Over 2.5 years' follow-up, patients (n=294) with low FT3 (<2.85 pg/ml) and high FT4 (>=0.88 ng/dl) had the highest all-cause mortality (18.2%), whereas patients (n=293) with high FT3 and low FT4 had the lowest all-cause mortality (3.8%) (P for trend <0.0001). Conclusions: Both FT3 and FT4 were independently associated with in-hospital CS development in patients with STEMI treated with PCI. Patients with lower range of FT3 and upper range of FT4 had the worst outcomes in long-term follow-up.