title: Association of cystatin C with ischemia in patients with coronary heart disease.
abstract: BACKGROUND
  Elevated concentrations of cystatin C are associated with greater cardiovascular morbidity and mortality. We sought to determine whether elevated concentrations of cystatin C were associated with inducible ischemia in patients with coronary heart disease (CHD).
  
  
  METHODS
  We measured serum cystatin C and performed exercise treadmill testing with stress echocardiography in a cross-sectional study of 899 outpatients with CHD.
  
  
  RESULTS
  Among the 241 participants in the highest quartile of cystatin C (>1.30 mg/L), 38% had inducible ischemia, compared with 13% of those in the lowest quartile of cystatin C < 0.92 mg/L; adjusted odds ratio [OR]: 2.1; 95% confidence interval [CI]: 1.2 to 3.8; p = 0.01). However, this association differed in participants with and without a history of coronary artery bypass graft (CABG), as well as in users and nonusers of beta-blockers and statins (p values for interaction < 0.1). Among participants without a history of CABG, 35% of those in the highest quartile and 9% of those in the lowest quartile of cystatin C had inducible ischemia (adjusted OR: 3.05; 95% CI: 1.3-6.9; p = 0.008). Among participants who were not using beta-blockers, 44% of those in the highest quartile and 7% in the lowest quartile of cystatin C had inducible ischemia (adjusted OR: 5.3; 95% CI: 1.8-15.5; p = 0.002). Among participants who were not using statins, 39% of participants in the highest quartile and 4% of those in the lowest quartile had inducible ischemia (adjusted OR: 10.3; 95% CI: 2.5-43.3; p = 0.001).
  
  
  CONCLUSIONS
  Elevated levels of cystatin C are independently associated with inducible ischemia among outpatients with stable coronary disease.
authors.affiliation: Division of Cardiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA. Rajet.Deo@uphs.upenn.edu
authors.forename: Rajet
authors.initials: R
authors.lastname: Deo
authors.forename: Michael G
authors.initials: MG
authors.lastname: Shlipak
authors.forename: Joachim H
authors.initials: JH
authors.lastname: Ix
authors.forename: Sadia
authors.initials: S
authors.lastname: Ali
authors.forename: Nelson B
authors.initials: NB
authors.lastname: Schiller
authors.forename: Mary A
authors.initials: MA
authors.lastname: Whooley
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D001026:Coronary Artery Bypass; D003327:Coronary Disease / Q000097:blood / Q000150:complications / Q000175:diagnosis* / Q000628:therapy; D003430:Cross-Sectional Studies; D055316:Cystatin C / Q000097:blood*; D025401:Echocardiography, Stress; D005080:Exercise Test; D005260:Female; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000097:blood / Q000175:diagnosis* / Q000209:etiology; D016017:Odds Ratio; D011237:Predictive Value of Tests; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index; D015854:Up-Regulation
chemical_list: D000319:Adrenergic beta-Antagonists; D015415:Biomarkers; C525030:CST3 protein, human; D055316:Cystatin C; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors