title: The effect of low FT3 levels on coronary artery calcification and MACE in outpatients with suspected coronary artery disease.
abstract: OBJECTIVE
  Considerable evidence suggests that thyroid dysfunction, especially hypothyroidism, may lead to coronary artery disease (CAD). The aim of this study is to investigate the effect of low serum levels of free triiodothyronine (FT3) on coronary artery calcification in outpatients with suspected CAD and the occurrence rate of major adverse cardiac events (MACE) in these patients.
  
  
  METHODS
  A total of 588 outpatients with suspected CAD were enrolled in this study. The patients' blood samples were assayed for FT3, free thyroxine, thyroid stimulating hormone and serum lipids. On the basis of FT3 levels, these patients were divided into low FT3 (FT3<3.5 pmol/l; n=127) and normal FT3 (≥3.5 pmol/l; n=461) groups. Coronary artery calcification scores (CACS) were measured using dual-source computed tomography. The occurrence of MACE was recorded during the follow-up period (8-29 months) and their relationship with FT3 levels was investigated.
  
  
  RESULTS
  Patients with low FT3 levels had higher CACS (337.52±339.36 vs. 194.89±347.29, P<0.001) and a higher incidence of MACE (7.9 vs. 2.2%, P=0.002) compared with those with normal FT3 levels (≥3.5 pmol/l). Logistic regression analysis showed that the FT3 levels are inversely associated with CACS (odds ratio=0.463, 95% confidence interval=0.282-0.761, P=0.002) and patients with CACS greater than 100 have lower FT3 levels than those with lower CACS (P<0.001). Kaplan-Meier analysis showed that patients with low FT3 levels have a higher incidence of MACE.
  
  
  CONCLUSIONS
  FT3 levels were inversely associated with CACS and the incidence of MACE in patients with suspected CAD. A low FT3 level was an important predictor of the occurrence of MACE.
authors: aDepartment of Cardiology, Zhengzhou University People's Hospital bHenan Institute of Cardiovascular Epidemiology, Zhengzhou, China.
authors: Lijie
authors: L
authors: Zhu
authors: Chuanyu
authors: C
authors: Gao
authors: Xianpei
authors: X
authors: Wang
authors: Datun
authors: D
authors: Qi
authors: You
authors: Y
authors: Zhang
authors: Muwei
authors: M
authors: Li
authors: Weili
authors: W
authors: Liu
authors: Peiyuan
authors: P
authors: Hao
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D016009:Chi-Square Distribution; D002681:China / Q000453:epidemiology; D017023:Coronary Angiography / Q000379:methods; D001026:Coronary Artery Bypass; D003324:Coronary Artery Disease / Q000175:diagnosis / Q000453:epidemiology* / Q000401:mortality / Q000628:therapy; D018572:Disease-Free Survival; D015536:Down-Regulation; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology* / Q000401:mortality; D015994:Incidence; D053208:Kaplan-Meier Estimate; D016014:Linear Models; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009203:Myocardial Infarction / Q000175:diagnosis / Q000453:epidemiology* / Q000401:mortality / Q000628:therapy; D016017:Odds Ratio; D010045:Outpatients; D062645:Percutaneous Coronary Intervention; D012307:Risk Factors; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D014284:Triiodothyronine / Q000097:blood*; D061205:Vascular Calcification / Q000175:diagnosis / Q000453:epidemiology* / Q000401:mortality / Q000628:therapy
chemical_list: D015415:Biomarkers; D014284:Triiodothyronine