title: Serum chitotriosidase activity, a marker of activated macrophages, predicts new cardiovascular events independently of C-reactive protein.
abstract: BACKGROUND
  C-reactive protein (CRP) is a well-established inflammation marker associated with cardiovascular risk. However, its relationship with chitotriosidase activity, a novel marker of activated macrophages highly expressed in human atherosclerotic plaques, is unknown. Therefore, we sought to determine if serum chitotriosidase activity predicts the risk of new coronary events, and to analyze its relationship with CRP.
  
  
  METHODS
  Chitotriosidase activity and genotype, and high-sensitivity CRP were measured at baseline in 133 middle-aged men with stable coronary heart disease, who were followed for the occurrence of cardiovascular morbidity and mortality for a mean of 4 years. We studied the value of these proteins in predicting the risk of new cardiovascular events.
  
  
  RESULTS
  Serum chitotriosidase activity was higher in the group of subjects with a prespecified major event (nonfatal myocardial infarction, nonfatal ischemic stroke, coronary revascularization procedures and death from cardiovascular causes) than in the group of subjects without event, 116 +/- 30.9 nmol/ml x h versus 74.2 +/- 5.69 nmol/ml x h, respectively (p = 0.042). The baseline values of chitotriosidase activity and CRP did not correlate (R = 0.104, p = 0.266), but both parameters were related to a reduction of event-free survival in the Cox regression analysis, with relative risks of 2.61 (p = 0.060) and 2.56 (p = 0.019), respectively. Chitotriosidase activity seems to be a better marker for new events occurring after 2 years of follow-up than in the first 2 years. Both markers had similar predictive values, and their sensitivity (64%) and negative predictive value (84%) were improved when combined.
  
  
  CONCLUSIONS
  Our results suggest that serum chitotriosidase activity predicts the risk of new cardiovascular events in the following 4 years. This new cardiovascular risk marker is independent of CRP and, when combined, the prediction of the risk of new cardiovascular events and the identification of a lower risk group seem to improve.
authors.affiliation: Laboratorio de Investigación Molecular, Hospital Universitario Miguel Servet, Zaragoza, Spain. martieda@salud.aragon.es
authors.forename: Marta
authors.initials: M
authors.lastname: Artieda
authors.forename: Ana
authors.initials: A
authors.lastname: Cenarro
authors.forename: Alberto
authors.initials: A
authors.lastname: Gañán
authors.forename: Antonela
authors.initials: A
authors.lastname: Lukic
authors.forename: Eva
authors.initials: E
authors.lastname: Moreno
authors.forename: José
authors.initials: J
authors.lastname: Puzo
authors.forename: Miguel
authors.initials: M
authors.lastname: Pocoví
authors.forename: Fernando
authors.initials: F
authors.lastname: Civeira
mesh_terms: D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000032:analysis; D003327:Coronary Disease / Q000097:blood*; D006596:Hexosaminidases / Q000097:blood*; D006801:Humans; D008264:Macrophages / Q000502:physiology; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests
chemical_list: D015415:Biomarkers; D002097:C-Reactive Protein; D006596:Hexosaminidases; C086400:chitotriosidase