title: The relationship between coronary artery calcium score and the long-term mortality among patients with minimal or absent coronary artery risk factors.
abstract: BACKGROUND
  Coronary artery calcium (CAC) is strongly predictive of all-cause mortality in intermediate-risk groups, but this relationship is not well defined in very low-risk individuals. We investigated the relationship between CAC scoring and the long-term all-cause mortality among patients with ≤ 1 cardiovascular disease (CVD) risk factor.
  
  
  METHODS
  We analyzed a retrospective cohort of 5584 asymptomatic patients with no known CVD (mean 56.6 ± 11.6 years, 69%men) and ≤ 1 risk factor who were physician referred for a CAC scan. Mortality was ascertained through linkage with the Social Security Death Index. We calculated the prevalence of CAC stratified by age and risk factors. We also examined the association between CAC and mortality using multivariable Cox Proportional hazards models.
  
  
  RESULTS
  During a mean follow-up of 10.4 ± 3.1 years, 168 individuals (3.0%) died. Overall, 54.5% of patients had a CAC >0 and 9.8% had CAC ≥ 400. There was a greater risk of mortality with increasing CAC 1-99 (HR 1.9, 95% CI 1.2-3.1), 100-399 (HR 2.1, 95% CI 1.2-3.6) and ≥ 400 (HR 2.8, 95% CI 1.6-4.8) compared to CAC=0 (p<0.0001 for trend). Similar results were observed when the population was stratified by zero or one risk factor. Among patients < 45 years old, there was a 0.7% incidence of mortality compared to 8.1% for individuals ≥ 65 years old.
  
  
  CONCLUSIONS
  During long-term follow-up, an increasing CAC was significantly associated with a higher risk of all-cause mortality among patients with a very low CVD risk factor profile. CAC scanning may be a potentially useful tool for risk stratification among low CVD risk individuals who are ≥ 45 years old.
authors.affiliation: Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, USA.
authors.forename: Rine
authors.initials: R
authors.lastname: Nakanishi
authors.affiliation: Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, USA.
authors.forename: Dong
authors.initials: D
authors.lastname: Li
authors.affiliation: Department of the Prevention of Heart Disease, The Johns Hopkins Ciccarone Center, Baltimore, MD, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Blaha
authors.affiliation: Department of the Prevention of Heart Disease, The Johns Hopkins Ciccarone Center, Baltimore, MD, USA.
authors.forename: Seamus P
authors.initials: SP
authors.lastname: Whelton
authors.affiliation: Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, USA.
authors.forename: Suguru
authors.initials: S
authors.lastname: Matsumoto
authors.affiliation: Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, USA.
authors.forename: Anas
authors.initials: A
authors.lastname: Alani
authors.affiliation: Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, USA.
authors.forename: Panteha
authors.initials: P
authors.lastname: Rezaeian
authors.affiliation: Department of the Prevention of Heart Disease, The Johns Hopkins Ciccarone Center, Baltimore, MD, USA.
authors.forename: Roger S
authors.initials: RS
authors.lastname: Blumenthal
authors.affiliation: Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, USA. Electronic address: mbudoff@labiomed.org.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Budoff
mesh_terms: D000368:Aged; D002118:Calcium / Q000378:metabolism*; D017023:Coronary Angiography / Q000379:methods*; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging / Q000378:metabolism / Q000401:mortality*; D003331:Coronary Vessels / Q000000981:diagnostic imaging / Q000378:metabolism*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D014057:Tomography, X-Ray Computed; D014481:United States / Q000453:epidemiology; D061205:Vascular Calcification / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000378:metabolism
chemical_list: D002118:Calcium
keywords: Coronary artery calcification; Long-term; Low risk; Mortality risk; Risk factor