Effect Of Thyroid Dysfunction On Prognosis In Acute Myocardial Infarction

Objective:The purpose of this article was to investigate the effects of thyroid dysfunction on the adverse prognosis of patients with acute myocardial infarction.The aim was to explore the potential risk factors of coronary heart disease.In the first part,we use retrospective observational research methods to analyze the current AMI patients with thyroid function.We further evaluate the clinical characteristics of subclinical hypothyroidism,subclinical hyperthyroidism,low T3 syndrome in patients with AMI and the effects of recent and long-term adverse events.In the second part,the meta-analysis method was used to study the thyroid function of ACS patients and the effect of thyroid function on the poor prognosis of patients with ACS.Methods:A total of 535 patients in the Second Hospital of Tianjin Medical University was included in this study.We record the recent and long-term adverse events during one year follow-up to analysis different prognosis between patients in different group with AMI.The second part of the study have searched Pubmed,Embass and Cochrane database for all studies which mentioned about thyroid hormone levels and patients with ACS.We performed a systematic review and meta-analysis to explore the prevalence of low T3 syndrome in patients with ACS and its relationship with mortality and adverse events in patients with ACS.Results:1.The following indicators vary among the four groups: history of diabetes,history of tobacco,cerebral infarction history,admission systolic blood pressure and heart rate,shock index,urea nitrogen,uric acid,creatinine,random blood glucose admission,the second day of admission fasting blood glucose,White blood cells,erythrocytes,hemoglobin,hematocrit,erythrocyte distribution,platelet,glycosylated hemoglobin,creatine kinase isoenzyme,triglyceride,C-reactive protein,phospholipase A2 and cystatin C.At the same time,patients with low T3 syndrome group had lower LVEF than the other three groups.2.The proportion of infarct-related anterior descending artery and right coronary artery in patients with normal thyroid function was significantly lower than that in the other three groups.The proportion of triple vessel disease was significantly higher in the patients with low T3 syndrome than in the other three groups.The Gensini score in patients with normal thyroid function was significantly lower than that in patients with thyroid dysfunction,and the Gensini score was significantly higher in patients with low T3 syndrome.Through the retrospective analysis of each group of clinical treatment,low T3 syndrome group received ACEI/ARB treatment ratio was significantly lower than the other three groups and the proportion of diuretic application significantly increased.Compared with the poor prognosis during hospitalization,the incidence of heart failure were significantly higher in the patients with low T3 syndrome than those in the other three groups(50.0% vs 12.2%,30.6%,28.8% P<0.01).Comparison of adverse events during one year follow-up period,the incidence of nonfatal myocardial infarction was significantly higher in subclinical hyperthyroid patients than in the other three groups and also the same as heart failure(26.3% vs 7.5%,6.1%,23.1% P<0.01).3.Logistic regression analysis of poor prognosis risk factors in patients with acute myocardial infarction showed that FT3,FT4,BUN,WBC,RBC and LVEF entered the regression equation.The correlation between FT3 and poor prognosis was(OR=0.335,95% CI:0.222-0.506,P=0.000).Logistic regression analysis of long-term poor prognosis related risk factors was TSH,WBC,RBC,LVEF(P <0.05).4.Kaplan-Meier analysis showed that the survival rate of patients with normal thyroid function and subclinical hypothyroidism was higher than that of subclinical hyperthyroidism and low T3 syndrome.The difference was statistically significant(Log-Rank test,χ2 = 60.089,P = 0.000).5.Meta-analysis showed that the incidence of low T3 syndrome in patients with acute coronary syndromes was 23%(95% CI: 0.16-0.30)and the overall incidence of low T3 syndrome in acute myocardial infarction was 20%(95 % CI: 0.11-0.28).6.The risk of death in the low T3 syndrome group was significantly higher than that in the control group(OR = 12.81,95% CI: 5.38-30.51,P <0.01),the same as long-term mortality(OR = 6.52,95% CI: 3.69-11.51,P <0.01).Conclusion:The incidence of thyroid dysfunction was higher in patients with acute myocardial infarction.Compared with those with normal thyroid function,the myocardial injury markers and inflammatory markers were significantly increased in patients with low T3 syndrome,and the cardiac function LVEF was significantly decreased.Serum FT3 concentrations were also associated with the Gensini score and independently predicted the incidence of long-term and recent adverse events,and could be used as one of the predictors of poor prognosis in patients with acute myocardial infarction.Meta-analysis showed that low T3 syndrome was highly prevalent in AMI patients and was an independent predictor of short-term and long-term adverse prognosis.Thyroid function texting is necessary to guide the clinician to determine the patient’s condition in AMI.Large-scale clinical researches are also needed.