title: Thoracic aortic calcification and coronary heart disease events: the multi-ethnic study of atherosclerosis (MESA).
abstract: BACKGROUND
  The presence and extent of coronary artery calcium (CAC) is an independent predictor of coronary heart disease (CHD) morbidity and mortality. Few studies have evaluated interactions or independent incremental risk for coronary and thoracic aortic calcification (TAC). The independent predictive value of TAC for CHD events is not well-established.
  
  
  METHODS
  This study used risk factor and computed tomography scan data from 6807 participants in the multi-ethnic study of atherosclerosis (MESA). Using the same images for each participant, TAC and CAC were each computed using the Agatston method. The study subjects were free of incident CHD at entry into the study.
  
  
  RESULTS
  The mean age of the study population (n=6807) was 62±10 years (47% males). At baseline, the prevalence of TAC and CAC was 28% (1904/6809) and 50% (3393/6809), respectively. Over 4.5±0.9 years, a total of 232 participants (3.41%) had CHD events, of which 132 (1.94%) had a hard event (myocardial infarction, resuscitated cardiac arrest, or CHD death). There was a significant interaction between gender and TAC for CHD events (p<0.05). Specifically, in women, the risk of all CHD event was nearly 3-fold greater among those with any TAC (hazard ratio: 3.04, 95% CI: 1.60-5.76). After further adjustment for increasing CAC score, this risk was attenuated but remained robust (HR: 2.15, 95% CI: 1.10-4.17). Conversely, there was no significant association between TAC and incident CHD in men. In women, the likelihood ratio chi square statistics indicate that the addition of TAC contributed significantly to predicting incident CHD event above that provided by traditional risk factors alone (chi square=12.44, p=0.0004) as well as risk factors+CAC scores (chi square=5.33, p=0.02). On the other hand, addition of TAC only contributed in the prediction of hard CHD events to traditional risk factors (chi-square=4.33, p=0.04) in women, without contributing to the model containing both risk factors and CAC scores (chi square=1.55, p=0.21).
  
  
  CONCLUSIONS
  Our study indicates that TAC is a significant predictor of future coronary events only in women, independent of CAC. On studies obtained for either cardiac or lung applications, determination of TAC may provide modest supplementary prognostic information in women with no extra cost or radiation.
authors.affiliation: Division of Cardiology, Los Angeles Biomedical Research Institute at Harbor-UCLA, Torrance, CA, United States.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Budoff
authors.forename: Khurram
authors.initials: K
authors.lastname: Nasir
authors.forename: Ronit
authors.initials: R
authors.lastname: Katz
authors.forename: Junichiro
authors.initials: J
authors.lastname: Takasu
authors.forename: J Jeffery
authors.initials: JJ
authors.lastname: Carr
authors.forename: Nathan D
authors.initials: ND
authors.lastname: Wong
authors.forename: Matthew
authors.initials: M
authors.lastname: Allison
authors.forename: Joao A C
authors.initials: JA
authors.lastname: Lima
authors.forename: Robert
authors.initials: R
authors.lastname: Detrano
authors.forename: Roger S
authors.initials: RS
authors.lastname: Blumenthal
authors.forename: Richard
authors.initials: R
authors.lastname: Kronmal
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001013:Aorta, Thoracic / Q000000981:diagnostic imaging; D001018:Aortic Diseases / Q000150:complications*; D002114:Calcinosis / Q000150:complications*; D015331:Cohort Studies; D003324:Coronary Artery Disease / Q000150:complications; D003327:Coronary Disease / Q000000981:diagnostic imaging / Q000209:etiology*; D003331:Coronary Vessels; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D014057:Tomography, X-Ray Computed