title: Plasma α1-antitrypsin: a neglected predictor of angiographic severity in patients with stable angina pectoris.
abstract: BACKGROUND
  As an acute phase protein, α1-antitrypsin (AAT) has been extensively studied in acute coronary syndrome, but it is unclear whether a relationship exists between AAT and stable angina pectoris (SAP). The purpose of the present study was to investigate the association between AAT plasma levels and SAP.
  
  
  METHODS
  Overall, 103 SAP patients diagnosed by coronary angiography and clinical manifestations and 118 control subjects matched for age and gender were enrolled in this case-control study. Plasma levels of AAT, high-sensitivity C-reactive protein (hsCRP), lipid profiles and other clinical parameters were assayed for all participants. The severity of coronary lesions was evaluated based on the Gensini score (GS) assessed by coronary angiography.
  
  
  RESULTS
  Positively correlated with the GS (r = 0.564, P < 0.001), the plasma AAT level in the SAP group was significantly higher than that in the control group (142.08 ± 19.61 mg/dl vs. 125.50 ± 19.67 mg/dl, P < 0.001). The plasma AAT level was an independent predictor for both SAP (odds ratio [OR] = 1.037, 95% confidence interval [CI]: 1.020-1.054, P < 0.001) and a high GS (OR = 1.087, 95% CI: 1.051-1.124, P < 0.001) in a multivariate logistic regression model. In the receiver operating characteristic curve analysis, plasma AAT level was found to have a larger area under the curve (AUC) for predicting a high GS (AUC = 0.858, 95% CI: 0.788-0.929, P < 0.001) than that of hsCRP (AUC = 0.665, 95% CI: 0.557-0.773, P = 0.006; Z = 2.9363, P < 0.001), with an optimal cut-off value of 137.85 mg/dl (sensitivity: 94.3%, specificity: 68.2%).
  
  
  CONCLUSIONS
  Plasma AAT levels correlate with both the presence and severity of coronary stenosis in patients with SAP, suggesting that it could be a potential predictive marker of severe stenosis in SAP patients.
authors.forename: Hui
authors.initials: H
authors.lastname: Zhao
authors.forename: Hong
authors.initials: H
authors.lastname: Liu
authors.forename: Lin
authors.initials: L
authors.lastname: Chai
authors.forename: Ping
authors.initials: P
authors.lastname: Xu
authors.forename: Lu
authors.initials: L
authors.lastname: Hua
authors.forename: Xiao-Yuan
authors.initials: XY
authors.lastname: Guan
authors.forename: Bing
authors.initials: B
authors.lastname: Duan
authors.forename: Yi-Ling
authors.initials: YL
authors.lastname: Huang
authors.affiliation: Key Laboratory of Clinical Trial Research in Cardiovascular Drugs, Ministry of Health, State Key Laboratory of Cardiovascular Diseases, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100037, China.
authors.forename: Yi-Shi
authors.initials: YS
authors.lastname: Li
mesh_terms: D000328:Adult; D000368:Aged; D000787:Angina Pectoris / Q000097:blood* / Q000000981:diagnostic imaging; D060050:Angina, Stable / Q000097:blood* / Q000000981:diagnostic imaging; D016022:Case-Control Studies; D017023:Coronary Angiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D000515:alpha 1-Antitrypsin / Q000097:blood*
chemical_list: D000515:alpha 1-Antitrypsin