title: Rationale and design of the coronary artery calcium consortium: A multicenter cohort study.
abstract: BACKGROUND
  Although coronary artery calcium (CAC) has been investigated for over two decades, there is very limited data on the association of CAC with cause of death. The CAC Consortium is a large ongoing multi-center observational cohort of individuals who underwent non-contrast cardiac-gated CAC testing and systematic, prospective, long-term follow-up for mortality with ascertainment of cause of death.
  
  
  METHODS
  Four participating institutions from three states within the US (California, Minnesota, and Ohio) have contributed individual-level patient data to the CAC Consortium (spanning years 1991-2010). All CAC scans were clinically indicated and physician-referred in patients without a known history of coronary heart disease. Using strict inclusion and exclusion criteria to minimize missing data and to eliminate non-dedicated CAC scans (i.e. concomitant CT angiography), a sharply defined and well-characterized cohort of 66,636 patients was assembled. Mortality status was ascertained using the Social Security Administration Death Master File and a validated algorithm. In addition, death certificates were obtained from the National Death Index and categorized using ICD (International Classification of Diseases) codes into common causes of death.
  
  
  RESULTS
  Mean patient age was 54 ± 11 years and the majority were male (67%). Prevalence of CVD risk factors was similar across sites and 55% had a <5% estimated 10-year atherosclerotic cardiovascular disease (ASCVD) risk. Approximately 45% had a Calcium score of 0 and 11% had an Agatston Score ≥400. Over a mean follow-up of 12 ± 4 years, there were 3158 deaths (4.15 per 1000 person-years). The majority of deaths were due to cancer (37%) and CVD (32%). Most CVD deaths were due to CHD (54%) followed by stroke (17%). In general, CAC score distributions were similar across sites, and there were similar cause of death patterns.
  
  
  CONCLUSIONS
  The CAC Consortium is large and highly generalizable data set that is uniquely positioned to expand the understanding of CAC as a predictor of mortality risk across the spectrum of disease states, allowing innovative modeling of the competing risks of cardiovascular and non-cardiovascular death.
authors.affiliation: Johns Hopkins Ciccarone Center for Prevention of Heart Disease, Baltimore, MD, United States. Electronic address: mblaha1@jhmi.edu.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Blaha
authors.affiliation: Johns Hopkins Ciccarone Center for Prevention of Heart Disease, Baltimore, MD, United States.
authors.forename: Seamus P
authors.initials: SP
authors.lastname: Whelton
authors.affiliation: Johns Hopkins Ciccarone Center for Prevention of Heart Disease, Baltimore, MD, United States.
authors.forename: Mahmoud
authors.initials: M
authors.lastname: Al Rifai
authors.affiliation: Johns Hopkins Ciccarone Center for Prevention of Heart Disease, Baltimore, MD, United States.
authors.forename: Zeina A
authors.initials: ZA
authors.lastname: Dardari
authors.affiliation: Department of Medicine, Emory University School of Medicine, Atlanta, GA, United States.
authors.forename: Leslee J
authors.initials: LJ
authors.lastname: Shaw
authors.affiliation: King Abdul-Aziz Cardiac Center, Riyadh, Saudi Arabia.
authors.forename: Mouaz H
authors.initials: MH
authors.lastname: Al-Mallah
authors.affiliation: Department of Epidemiology, Welch Center for Prevention, Epidemiology, and Clinical Research, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, United States.
authors.forename: Kuni
authors.initials: K
authors.lastname: Matsushita
authors.affiliation: Princeton Longevity Center, Princeton, NJ, United States.
authors.forename: John A
authors.initials: JA
authors.lastname: Rumberger
authors.affiliation: Department of Imaging, Cedars-Sinai Medical Center, Los Angeles, CA, United States.
authors.forename: Daniel S
authors.initials: DS
authors.lastname: Berman
authors.affiliation: Department of Medicine, Harbor UCLA Medical Center, Los Angeles, CA, United States.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Budoff
authors.affiliation: Minneapolis Heart Institute, Abbott Northwestern Hospital, Minneapolis, MN, United States.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Miedema
authors.affiliation: Johns Hopkins Ciccarone Center for Prevention of Heart Disease, Baltimore, MD, United States; Center for Prevention and Wellness, Baptist Health South Florida, Miami, FL, United States.
authors.forename: Khurram
authors.initials: K
authors.lastname: Nasir
mesh_terms: D000328:Adult; D000368:Aged; D002423:Cause of Death; D000072226:Computed Tomography Angiography; D017023:Coronary Angiography / Q000379:methods; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging / Q000401:mortality*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D015995:Prevalence; D011379:Prognosis; D012107:Research Design; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D014481:United States / Q000453:epidemiology; D061205:Vascular Calcification / Q000000981:diagnostic imaging / Q000401:mortality*
keywords: Coronary artery calcium