title: Quantification of coronary artery calcium in nongated CT to predict cardiovascular events in male lung cancer screening participants: results of the NELSON study.
abstract: OBJECTIVE
  To evaluate the incremental prognostic value of the number and maximum volume of coronary artery calcifications over modified Agatston score strata, age, pack-years, and smoking status for predicting cardiovascular events.
  
  
  METHODS
  A total of 3559 male current and former smokers received a CT examination for lung cancer screening. Smoking characteristics, patient demographics, and physician-diagnosed cardiovascular events were collected. Images were acquired without electrocardiography gating on 16-slice CT scanners. The association between the presence of both fatal and nonfatal cardiovascular events and the predictors was quantified using Cox proportional hazard analysis.
  
  
  RESULTS
  Median follow-up period was 2.9 years. Incident cardiovascular events occurred in 186 participants. Adjusted hazard ratios for modified Agatston score strata of 1 to 10, 11 to 100, 101 to 400, and >400 were 3.39 (95% confidence interval [CI], 1.20-9.59), 6.52 (95% CI, 2.73-15.60), 6.58 (95% CI, 2.75-15.78), and 12.58 (95% CI, 5.42-29.16), respectively. Moreover, comparing the models with and without modified Agatston score strata to the model with age, pack-years, and smoking status yielded a significantly better net reclassification improvement (NRI; 27.3%; P < .0001). Adding the number of calcifications to the model with age, pack-years, smoking status, and modified Agatston score strata resulted in a slightly better NRI (1.68%; P = .0490) with a hazard ratio of 1.13 (95% CI, 1.05-1.21) per 10 calcifications. The incremental prognostic information contained in the volume of the largest calcification was not statistically significant (NRI, 0.14%; P = .3458).
  
  
  CONCLUSIONS
  Cardiovascular event rate increased with higher numbers of calcified lesions. The number but not maximum volume of calcifications has independent, although minimal, prognostic value over age, pack-years, smoking status, and modified Agatston score strata in our population.
authors.affiliation: Department of Radiology, University Medical Center Utrecht, Heidelberglaan 100, 3508 GA Utrecht, The Netherlands. Electronic address: rtakx@umcutrecht.nl.
authors.forename: Richard A P
authors.initials: RA
authors.lastname: Takx
authors.affiliation: Image Sciences Institute, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Ivana
authors.initials: I
authors.lastname: Išgum
authors.affiliation: Department of Radiology, University Medical Center Utrecht, Heidelberglaan 100, 3508 GA Utrecht, The Netherlands.
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Willemink
authors.affiliation: Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Yolanda
authors.initials: Y
authors.lastname: van der Graaf
authors.affiliation: Department of Public Health, Erasmus Medical Center, Rotterdam, The Netherlands.
authors.forename: Harry J
authors.initials: HJ
authors.lastname: de Koning
authors.affiliation: Center for Medical Imaging-North East Netherlands, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands; Department of Radiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
authors.forename: Rozemarijn
authors.initials: R
authors.lastname: Vliegenthart
authors.affiliation: Center for Medical Imaging-North East Netherlands, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
authors.forename: Matthijs
authors.initials: M
authors.lastname: Oudkerk
authors.affiliation: Department of Radiology, University Medical Center Utrecht, Heidelberglaan 100, 3508 GA Utrecht, The Netherlands.
authors.forename: Tim
authors.initials: T
authors.lastname: Leiner
authors.affiliation: Department of Radiology, University Medical Center Utrecht, Heidelberglaan 100, 3508 GA Utrecht, The Netherlands.
authors.forename: Pim A
authors.initials: PA
authors.lastname: de Jong
mesh_terms: D017677:Age Distribution; D001185:Artificial Intelligence; D001530:Belgium / Q000453:epidemiology; D002114:Calcinosis / Q000000981:diagnostic imaging* / Q000401:mortality*; D015984:Causality; D015897:Comorbidity; D017023:Coronary Angiography / Q000706:statistics & numerical data; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000401:mortality*; D055088:Early Detection of Cancer / Q000706:statistics & numerical data; D006801:Humans; D015994:Incidence; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000401:mortality; D008297:Male; D008875:Middle Aged; D009426:Netherlands / Q000453:epidemiology; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods; D015203:Reproducibility of Results; D018570:Risk Assessment / Q000379:methods; D012680:Sensitivity and Specificity; D012907:Smoking / Q000453:epidemiology; D015996:Survival Rate; D014057:Tomography, X-Ray Computed / Q000706:statistics & numerical data*
keywords: Agatston score; Cardiovascular event; Computed tomography; Coronary artery calcification; Lung cancer screening