title: Prevalence and clinical characteristics of symptomatic patients with obstructive coronary artery disease in the absence of coronary calcifications.
abstract: OBJECTIVE
  The quantification of coronary calcification has established itself as a valid risk marker to predict cardiovascular events. However, data derived from cardiac multi-detector row computed tomography could demonstrate that the exclusion of coronary calcification is not synonymous with the exclusion of coronary artery disease (CAD). The aims of this retrospective analysis were to determine the prevalence of significant CAD in a symptomatic cohort with indications for invasive angiography but without coronary calcification (Agatston score 0) as assessed by multislice computed tomography and to investigate whether there were any differences in terms of risk factors between patients with and without significant CAD.
  
  
  METHODS
  Five hundred multislice computed tomographic scans (in 371 men and 129 women) were included in the analysis. Agatston scores were determined on native scans. All patients underwent coronary angiography to detect or rule out obstructive CAD. Patients with negative calcium scoring were selected and divided into two subgroups: those without obstructive CAD and those with obstructive CAD (luminal stenoses > 50%). These subgroups were characterized in terms of clinical characteristics (age and sex) and cardiovascular risk factors (diabetes mellitus, hypertension, hyperlipoproteinemia, familial predisposition, smoking, and overweight).
  
  
  RESULTS
  Sixty-one of 500 patients (12.2%) had negative calcium scores (Agatston score 0). Sixteen of these patients (26.3%, or 3.2% of the total population) had obstructive CAD according to invasive angiography. Patients with obstructive CAD were significantly older (mean age, 64 ± 9 vs 55 ± 10 years; P = .003) and were more frequently diabetic (25% vs 4%, P = .0389) than patients without obstructive CAD. There were no significant differences with regard to the other risk factors.
  
  
  CONCLUSIONS
  In this high-risk population, the absence of coronary calcification was not sufficient to rule out CAD. Among patients without coronary calcification, the presence of significant CAD was associated with increased age and the presence of diabetes mellitus.
authors.affiliation: Medizinische Klinik und Poliklinik III, Medizinische Universitätsklinik Tübingen, D-72076 Tübingen, Germany.
authors.forename: Tanja
authors.initials: T
authors.lastname: Drosch
authors.forename: Harald
authors.initials: H
authors.lastname: Brodoefel
authors.forename: Anja
authors.initials: A
authors.lastname: Reimann
authors.forename: Christoph
authors.initials: C
authors.lastname: Thomas
authors.forename: Ilias
authors.initials: I
authors.lastname: Tsiflikas
authors.forename: Martin
authors.initials: M
authors.lastname: Heuschmid
authors.forename: Stephen
authors.initials: S
authors.lastname: Schroeder
authors.forename: Christof
authors.initials: C
authors.lastname: Burgstahler
mesh_terms: D002114:Calcinosis / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D015897:Comorbidity; D017023:Coronary Angiography / Q000706:statistics & numerical data*; D023921:Coronary Stenosis / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D005260:Female; D005858:Germany / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors; D014057:Tomography, X-Ray Computed / Q000706:statistics & numerical data*