title: Coronary artery Calcium predicts Cardiovascular events in participants with a low lifetime risk of Cardiovascular disease: The Multi-Ethnic Study of Atherosclerosis (MESA).
abstract: OBJECTIVE
  Patients with a low lifetime risk of coronary heart disease (CHD) are not completely free of events over 10 years. We evaluated predictors for CHD among "low lifetime risk" participants in the population-based Multi-Ethnic Study of Atherosclerosis (MESA).
  
  
  METHODS
  MESA enrolled 6814 men and women aged 45-84 years who were free of baseline cardiovascular disease. Using established criteria of non-diabetic, non-smokers with total cholesterol ≤ 200 mg/dL, systolic BP ≤ 139 mmHg, and diastolic BP ≤ 89 mmHg at baseline, we identified 1391 participants with a low lifetime risk for cardiovascular disease. Baseline covariates were age, gender, ethnicity, HDL-C, C-reactive protein, family history of CHD, carotid intima-media thickness and coronary artery calcium (CAC). We calculated event rates and the number needed to scan (NNS) to identify one participant with CAC>0 and > 100.
  
  
  RESULTS
  Over 10.4 years median follow-up, there were 33 events (2.4%) in participants with low lifetime risk. There were 479 participants (34%) with CAC>0 including 183 (13%) with CAC>100. CAC was present in 25 (76%) participants who experienced an event. In multivariable analyses, only CAC>100 remained predictive of CHD (HR 4.6; 95% CI: 1.6-13.6; p = 0.005). The event rates for CAC = 0, CAC>0 and CAC>100 were 0.9/1,000, 5.7/1,000, and 11.0/1000 person-years, respectively. The NNS to identify one participant with CAC>0 and > 100 were 3 and 7.6, respectively.
  
  
  CONCLUSIONS
  While 10-year event rates were low in those with low lifetime risk, CAC was the strongest predictor of incident CHD. Identification of individuals with CAC = 0 and CAC>100 carries significant potential therapeutic implications.
authors: University of Texas Southwestern Medical Center, Department of Medicine, Division of Cardiology, Dallas, TX, USA; Johns Hopkins Ciccarone Center for the Prevention of Heart Disease, Baltimore, MD, USA.
authors: Parag H
authors: PH
authors: Joshi
authors: University of Texas Southwestern Medical Center, Department of Medicine, Division of Cardiology, Dallas, TX, USA; Johns Hopkins Ciccarone Center for the Prevention of Heart Disease, Baltimore, MD, USA.
authors: Birju
authors: B
authors: Patel
authors: Johns Hopkins Ciccarone Center for the Prevention of Heart Disease, Baltimore, MD, USA.
authors: Michael J
authors: MJ
authors: Blaha
authors: University of Texas Southwestern Medical Center, Department of Medicine, Division of Cardiology, Dallas, TX, USA.
authors: Jarett D
authors: JD
authors: Berry
authors: Departments of Medicine (Cardiovascular Division) and Radiology, Brigham and Women's Hospital, Boston, MA, USA.
authors: Ron
authors: R
authors: Blankstein
authors: Department of Medicine, Division of Cardiology Harbor-UCLA Medical Center, Torrance, CA, USA.
authors: Matthew J
authors: MJ
authors: Budoff
authors: Heart Disease Prevention Program, Division of Cardiology, University of California, Irvine, CA, USA.
authors: Nathan
authors: N
authors: Wong
authors: Center for Prevention and Wellness Research, Baptist Health South Florida, Miami, FL, USA.
authors: Arthur
authors: A
authors: Agatston
authors: Johns Hopkins Ciccarone Center for the Prevention of Heart Disease, Baltimore, MD, USA.
authors: Roger S
authors: RS
authors: Blumenthal
authors: Johns Hopkins Ciccarone Center for the Prevention of Heart Disease, Baltimore, MD, USA; Center for Prevention and Wellness Research, Baptist Health South Florida, Miami, FL, USA; Department of Medicine, Herbert Wertheim College of Medicine and Department of Epidemiology, Robert Stempel College of Public Health, Florida International University, Miami, FL, USA. Electronic address: Knasir1@jhmi.edu.
authors: Khurram
authors: K
authors: Nasir
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D058070:Asymptomatic Diseases; D059168:Carotid Intima-Media Thickness; D000072226:Computed Tomography Angiography; D017023:Coronary Angiography / Q000379:methods*; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000208:ethnology / Q000401:mortality; D003331:Coronary Vessels / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index; D013997:Time Factors; D014481:United States / Q000453:epidemiology; D061205:Vascular Calcification / Q000000981:diagnostic imaging* / Q000208:ethnology / Q000401:mortality
keywords: Coronary artery calcium; Coronary heart disease; Epidemiology; Lifetime risk