title: Diagnostic and prognostic value of absence of coronary artery calcification.
abstract: OBJECTIVE
  In this study, we systematically assessed the diagnostic and prognostic value of absence of coronary artery calcification (CAC) in asymptomatic and symptomatic individuals.
  
  
  BACKGROUND
  Presence of CAC is a well-established marker of coronary plaque burden and is associated with a higher risk of adverse cardiovascular outcomes. Absence of CAC has been suggested to be associated with a very low risk of significant coronary artery disease, as well as minimal risk of future events.
  
  
  METHODS
  We searched online databases (e.g., PubMed and MEDLINE) for original research articles published in English between January 1990 and March 2008 examining the diagnostic and prognostic utility of CAC.
  
  
  RESULTS
  A systematic review of published articles revealed 49 studies that fulfilled our criteria for inclusion. These included 13 studies assessing the relationship of CAC with adverse cardiovascular outcomes in 64,873 asymptomatic patients. In this cohort, 146 of 25,903 patients without CAC (0.56%) had a cardiovascular event during a mean follow-up period of 51 months. In the 7 studies assessing the prognostic value of CAC in a symptomatic population, 1.80% of patients without CAC had a cardiovascular event. Overall, 18 studies demonstrated that the presence of any CAC had a pooled sensitivity and negative predictive value of 98% and 93%, respectively, for detection of significant coronary artery disease on invasive coronary angiography. In 4,870 individuals undergoing myocardial perfusion and CAC testing, in the absence of CAC, only 6% demonstrated any sign of ischemia. Finally, 3 studies demonstrated that absence of CAC had a negative predictive value of 99% for ruling out acute coronary syndrome.
  
  
  CONCLUSIONS
  On the basis of our review of more than 85,000 patients, we conclude that the absence of CAC is associated with a very low risk of future cardiovascular events, with modest incremental value of other diagnostic tests in this very low-risk group.
authors.affiliation: Cardiac PET CT MRI Program, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
authors.forename: Ammar
authors.initials: A
authors.lastname: Sarwar
authors.forename: Leslee J
authors.initials: LJ
authors.lastname: Shaw
authors.forename: Michael D
authors.initials: MD
authors.lastname: Shapiro
authors.forename: Ron
authors.initials: R
authors.lastname: Blankstein
authors.forename: Udo
authors.initials: U
authors.lastname: Hoffmann
authors.forename: Udo
authors.initials: U
authors.lastname: Hoffman
authors.forename: Ricardo C
authors.initials: RC
authors.lastname: Cury
authors.forename: Suhny
authors.initials: S
authors.lastname: Abbara
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Brady
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Budoff
authors.forename: Roger S
authors.initials: RS
authors.lastname: Blumenthal
authors.forename: Khurram
authors.initials: K
authors.lastname: Nasir
mesh_terms: D054058:Acute Coronary Syndrome / Q000150:complications; D002114:Calcinosis / Q000150:complications / Q000000981:diagnostic imaging*; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000150:complications / Q000000981:diagnostic imaging*; D023921:Coronary Stenosis / Q000150:complications / Q000000981:diagnostic imaging; D006801:Humans; D017202:Myocardial Ischemia / Q000150:complications; D011237:Predictive Value of Tests; D011379:Prognosis; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed