title: Coronary artery calcification across ethnic groups in Singapore.
abstract: BACKGROUND
  In Singapore, the age-standardised event rates of myocardial infarction (MI) are 2- and 3-fold higher for Malays and Indians respectively compared to the Chinese. The objectives of this study were to determine the prevalence and quantity of coronary artery calcification (CAC) and non-calcified plaques across these 3 ethnic groups.
  
  
  METHODS
  This was a retrospective descriptive study. We identified 1041 patients (810 Chinese, 139 Malays, 92 Indians) without previous history of cardiovascular disease who underwent cardiac computed tomography for atypical chest pain evaluation. A cardiologist, who was blinded to the patients' clinical demographics, reviewed all scans. We retrospectively analysed all their case records.
  
  
  RESULTS
  Overall, Malays were most likely to be active smokers (P = 0.02), Indians had the highest prevalence of diabetes mellitus (P = 0.01) and Chinese had the highest mean age (P <0.0001). The overall prevalence of patients with non-calcified plaques as the only manifestation of sub-clinical coronary artery disease was 2.1%. There was no significant difference in the prevalence of CAC, mean CAC score or prevalence of non-calcified plaques among the 3 ethnic groups. Active smoking, age and hypertension were independent predictors of CAC. Non-calcified plaques were positively associated with male gender, age, dyslipidaemia and diabetes mellitus.
  
  
  CONCLUSIONS
  The higher MI rates in Malays and Indians in Singapore cannot be explained by any difference in CAC or non-calcified plaque. More research with prospective follow-up of larger patient populations is necessary to establish if ethnic-specific calibration of CAC measures is needed to adjust for differences among ethnic groups.
authors.affiliation: Department of Cardiology, Tan Tock Seng Hospital, Singapore.
authors.forename: Pow Li
authors.initials: PL
authors.lastname: Chia
authors.forename: Arul
authors.initials: A
authors.lastname: Earnest
authors.forename: Raymond
authors.initials: R
authors.lastname: Lee
authors.forename: Jamie
authors.initials: J
authors.lastname: Lim
authors.forename: Chun Pong
authors.initials: CP
authors.lastname: Wong
authors.forename: Yew Woon
authors.initials: YW
authors.lastname: Chia
authors.forename: James Y S
authors.initials: JY
authors.lastname: Weng
authors.forename: Anuradha
authors.initials: A
authors.lastname: Negi
authors.forename: Priyanka
authors.initials: P
authors.lastname: Khatri
authors.forename: David
authors.initials: D
authors.lastname: Foo
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D000704:Analysis of Variance; D044466:Asian People / Q000706:statistics & numerical data*; D016022:Case-Control Studies; D002681:China / Q000208:ethnology; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging / Q000208:ethnology*; D003331:Coronary Vessels / Q000000981:diagnostic imaging; D003920:Diabetes Mellitus / Q000208:ethnology; D050171:Dyslipidemias / Q000208:ethnology; D005260:Female; D006801:Humans; D006973:Hypertension / Q000208:ethnology; D007194:India / Q000208:ethnology; D008296:Malaysia / Q000208:ethnology; D008297:Male; D008875:Middle Aged; D058226:Plaque, Atherosclerotic / Q000000981:diagnostic imaging / Q000208:ethnology*; D015995:Prevalence; D012189:Retrospective Studies; D017678:Sex Distribution; D012846:Singapore / Q000453:epidemiology / Q000208:ethnology; D012907:Smoking / Q000208:ethnology; D014057:Tomography, X-Ray Computed; D061205:Vascular Calcification / Q000000981:diagnostic imaging / Q000208:ethnology*; D044465:White People / Q000706:statistics & numerical data*