Change of Serum Thyroid Hormone and its Clinical Significance in the Patients with Acute Coronary Syndrome

Objective To evaluate the changes of serum thyroid hormones in the patients with acute coronary syndrome(ACS).Methods 155 patients with ACS were divided into three groups as unstable angina pectoris(UAP) group,ST segment elevated myocardial infarction(STEMI) group and non-ST segment elevated myocardial infarction(NSTEMI) group,according to the symptoms,physical and laboratory examinations.There were 67 patients in the control group recruited during same period and detected no remarkable stenoses of their coronary angiography.The concentration of serum FT3 and rT3 was determined by radioimmunity(RIA),and the concentration of the C reactive protein(CRP) was determined by immunoturbidimetry(ITM).Results The serum level of FT3 of the ACS patients(3.92±0.72 pmol/L) was lower than that in the control group(4.59±0.65 pmol/L,P0.01),the serum level of FT3 of the patients in STEMI group(3.79±0.62 pmol/L) or in NSTEMI group(3.63±0.70 pmol/L) was lower than those in UAP group(4.22±0.72 pmol/L,P0.05).The serum level of rT3 of ACS patients(1.46±0.73 nmol/L) was higher than that in the control group(0.76±0.18 nmol/L,P0.01),the rT3 in the patients with NSTEMI(3.63±0.70 nmol/L) was higher than those in both of UAP(4.22±0.72 nmol/L,P0.05) and STEMI(3.79±0.62 nmol/L,P0.05) group.The serum level of CRP of all the patients with ACS(8.23±8.63 mg/L) was higher than that of the control group(3.60±3.87 mg/L,P0.01),the CRP in the patients with STEMI(10.41±9.80 mg/L) was higher than that in UAP(5.46±4.93 mg/L) group,the serum level of CRP of the patients with NSTEMI(9.18 ±10.20 mg/L) was higher than that in UAP,but lower than that in NSTEMI group,there were no significant difference in the patients with NSTEMI and either of the sub-groups(P0.05).The concentration of serum FT3 was negatively correlated with the serum level of CRP(r=-0.161,P0.05).Conclusion The results of this study demonstrate that low T3 syndrome exist in the patients with ACS.It is helpful to the differential diagnosis to determinate the serum level of FT3 and rT3 at the early stage of ACS.The serum level detection of CRP has clinical application value to the early diagnosis and condition evaluation of ACS.The change of thyroid hormones negatively correlates with CRP in the patients of ACS,but further studies are needed.