title: Prevalence and severity of coronary artery disease and adverse events among symptomatic patients with coronary artery calcification scores of zero undergoing coronary computed tomography angiography: results from the CONFIRM (Coronary CT Angiography Evaluation for Clinical Outcomes: An International Multicenter) registry.
abstract: OBJECTIVE
  The purpose of this study was to describe the prevalence and severity of coronary artery disease (CAD) in relation to prognosis in symptomatic patients without coronary artery calcification (CAC) undergoing coronary computed tomography angiography (CCTA).
  
  
  BACKGROUND
  The frequency and clinical relevance of CAD in patients without CAC are unclear.
  
  
  METHODS
  We identified 10,037 symptomatic patients without CAD who underwent concomitant CCTA and CAC scoring. CAD was assessed as <50%, ≥50%, and ≥70% stenosis. All-cause mortality and the composite endpoint of mortality, myocardial infarction, or late coronary revascularization (≥90 days after CCTA) were assessed.
  
  
  RESULTS
  Mean age was 57 years, 56% were men, and 51% had a CAC score of 0. Among patients with a CAC score of 0, 84% had no CAD, 13% had nonobstructive stenosis, and 3.5% had ≥50% stenosis (1.4% had ≥70% stenosis) on CCTA. A CAC score >0 had a sensitivity, specificity, and negative and positive predictive values for stenosis ≥50% of 89%, 59%, 96%, and 29%, respectively. During a median of 2.1 years, there was no difference in mortality among patients with a CAC score of 0 irrespective of obstructive CAD. Among 8,907 patients with follow-up for the composite endpoint, 3.9% with a CAC score of 0 and ≥50% stenosis experienced an event (hazard ratio: 5.7; 95% confidence interval: 2.5 to 13.1; p < 0.001) compared with 0.8% of patients with a CAC score of 0 and no obstructive CAD. Receiver-operator characteristic curve analysis demonstrated that the CAC score did not add incremental prognostic information compared with CAD extent on CCTA for the composite endpoint (CCTA area under the curve = 0.825; CAC + CCTA area under the curve = 0.826; p = 0.84).
  
  
  CONCLUSIONS
  In symptomatic patients with a CAC score of 0, obstructive CAD is possible and is associated with increased cardiovascular events. CAC scoring did not add incremental prognostic information to CCTA.
authors.affiliation: Cardiology Service, Walter Reed National Military Medical Center, 8901 Rockville Pike, Bethesda, MD 20889, USA. todd.villines@us.army.mil
authors.forename: Todd C
authors.initials: TC
authors.lastname: Villines
authors.forename: Edward A
authors.initials: EA
authors.lastname: Hulten
authors.forename: Leslee J
authors.initials: LJ
authors.lastname: Shaw
authors.forename: Manju
authors.initials: M
authors.lastname: Goyal
authors.forename: Allison
authors.initials: A
authors.lastname: Dunning
authors.forename: Stephan
authors.initials: S
authors.lastname: Achenbach
authors.forename: Mouaz
authors.initials: M
authors.lastname: Al-Mallah
authors.forename: Daniel S
authors.initials: DS
authors.lastname: Berman
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Budoff
authors.forename: Filippo
authors.initials: F
authors.lastname: Cademartiri
authors.forename: Tracy Q
authors.initials: TQ
authors.lastname: Callister
authors.forename: Hyuk-Jae
authors.initials: HJ
authors.lastname: Chang
authors.forename: Victor Y
authors.initials: VY
authors.lastname: Cheng
authors.forename: Kavitha
authors.initials: K
authors.lastname: Chinnaiyan
authors.forename: Benjamin J W
authors.initials: BJ
authors.lastname: Chow
authors.forename: Augustin
authors.initials: A
authors.lastname: Delago
authors.forename: Martin
authors.initials: M
authors.lastname: Hadamitzky
authors.forename: Jörg
authors.initials: J
authors.lastname: Hausleiter
authors.forename: Philipp
authors.initials: P
authors.lastname: Kaufmann
authors.forename: Fay Y
authors.initials: FY
authors.lastname: Lin
authors.forename: Erica
authors.initials: E
authors.lastname: Maffei
authors.forename: Gilbert L
authors.initials: GL
authors.lastname: Raff
authors.forename: James K
authors.initials: JK
authors.lastname: Min
mesh_terms: D002114:Calcinosis / Q000150:complications / Q000000981:diagnostic imaging*; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000150:complications / Q000000981:diagnostic imaging* / Q000401:mortality / Q000628:therapy; D023921:Coronary Stenosis / Q000150:complications / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000209:etiology; D009204:Myocardial Revascularization; D011379:Prognosis; D016016:Proportional Hazards Models; D012042:Registries; D012307:Risk Factors; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed