title: Inter-Ethnic Differences in Quantified Coronary Artery Disease Severity and All-Cause Mortality among Dutch and Singaporean Percutaneous Coronary Intervention Patients.
abstract: BACKGROUND
  Coronary artery disease (CAD) is a global problem with increasing incidence in Asia. Prior studies reported inter-ethnic differences in the prevalence of CAD rather than the severity of CAD. The angiographic "synergy between percutaneous coronary intervention (PCI) with taxus and cardiac surgery" (SYNTAX) score quantifies CAD severity and predicts outcomes. We studied CAD severity and all-cause mortality in four globally populous ethnic groups: Caucasians, Chinese, Indians and Malays.
  
  
  METHODS
  We quantified SYNTAX scores of 1,000 multi-ethnic patients undergoing PCI in two tertiary hospitals in the Netherlands (Caucasians) and Singapore (Chinese, Indians and Malays). Within each ethnicity we studied 150 patients with stable CAD and 100 with ST-elevated myocardial infarction (STEMI). We made inter-ethnic comparisons of SYNTAX scores and all-cause mortality.
  
  
  RESULTS
  Despite having a younger age (mean age Indians: 56.8 and Malays: 57.7 vs. Caucasians: 63.7 years), multivariable adjusted SYNTAX scores were significantly higher in Indians and Malays than Caucasians with stable CAD: 13.4 [11.9-14.9] and 13.4 [12.0-14.8] vs. 9.4 [8.1-10.8], p<0.001. Among STEMI patients, SYNTAX scores were highest in Chinese and Malays: 17.7 [15.9-19.5] and 18.8 [17.1-20.6] vs. 15.5 [13.5-17.4] and 12.7 [10.9-14.6] in Indians and Caucasians, p<0.001. Over a median follow-up of 709 days, 67 deaths (stable CAD: 37, STEMI: 30) occurred. Among STEMI patients, the SYNTAX score independently predicted all-cause mortality: HR 2.5 [1.7-3.8], p<0.001 for every 10-point increase. All-cause mortality was higher in Indian and Malay STEMI patients than Caucasians, independent of SYNTAX score (adjusted HR 7.2 [1.5-34.7], p=0.01 and 5.8 [1.2-27.2], p=0.02).
  
  
  CONCLUSIONS
  Among stable CAD and STEMI patients requiring PCI, CAD is more severe in Indians and Malays than in Caucasians, despite having a younger age. Moreover, Indian and Malay STEMI patients had a greater adjusted risk of all-cause mortality than Caucasians, independent of SYNTAX score.
authors.affiliation: Laboratory of Experimental Cardiology, University Medical Center Utrecht, Utrecht, the Netherlands; The Netherlands Heart Institute (ICIN), Utrecht, the Netherlands.
authors.forename: Crystel M
authors.initials: CM
authors.lastname: Gijsberts
authors.affiliation: Cardiac Department, National University Hospital, Singapore.
authors.forename: Aruni
authors.initials: A
authors.lastname: Seneviratna
authors.affiliation: Laboratory of Experimental Cardiology, University Medical Center Utrecht, Utrecht, the Netherlands.
authors.forename: Imo E
authors.initials: IE
authors.lastname: Hoefer
authors.affiliation: Department of Cardiology, University Medical Center Utrecht, Utrecht, the Netherlands.
authors.forename: Pierfrancesco
authors.initials: P
authors.lastname: Agostoni
authors.affiliation: Department of Cardiology, University Medical Center Utrecht, Utrecht, the Netherlands.
authors.forename: Saskia Z H
authors.initials: SZ
authors.lastname: Rittersma
authors.affiliation: Laboratory of Experimental Cardiology, University Medical Center Utrecht, Utrecht, the Netherlands.
authors.forename: Gerard
authors.initials: G
authors.lastname: Pasterkamp
authors.affiliation: Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Saw Swee Hock School of Public Health, National University of Singapore, Singapore.
authors.forename: Mikael
authors.initials: M
authors.lastname: Hartman
authors.affiliation: Cardiac Department, National University Hospital, Singapore; Department of Cardiology, Albert Einstein Hospital, Sao Paulo, Brazil.
authors.forename: Leonardo
authors.initials: L
authors.lastname: Pinto de Carvalho
authors.affiliation: Cardiac Department, National University Hospital, Singapore; Cardiovascular Research Institute (CVRI), National University Heart Centre (NUHCS), National University Health System, Singapore.
authors.forename: A Mark
authors.initials: AM
authors.lastname: Richards
authors.affiliation: Department of Cardiology, University Medical Center Utrecht, Utrecht, the Netherlands; Durrer Center for Cardiogenetic Research, ICIN-Netherlands Heart Institute, Utrecht, The Netherlands; Institute of Cardiovascular Science, faculty of Population Health Sciences, University College London, London, United Kingdom.
authors.forename: Folkert W
authors.initials: FW
authors.lastname: Asselbergs
authors.affiliation: Laboratory of Experimental Cardiology, University Medical Center Utrecht, Utrecht, the Netherlands; The Netherlands Heart Institute (ICIN), Utrecht, the Netherlands; Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Cardiovascular Research Institute (CVRI), National University Heart Centre (NUHCS), National University Health System, Singapore.
authors.forename: Dominique P V
authors.initials: DP
authors.lastname: de Kleijn
authors.affiliation: Cardiac Department, National University Hospital, Singapore; Cardiovascular Research Institute (CVRI), National University Heart Centre (NUHCS), National University Health System, Singapore.
authors.forename: Mark Y
authors.initials: MY
authors.lastname: Chan
mesh_terms: D000368:Aged; D044466:Asian People; D003324:Coronary Artery Disease / Q000175:diagnosis / Q000208:ethnology* / Q000401:mortality / Q000601:surgery; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009426:Netherlands; D062645:Percutaneous Coronary Intervention; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index; D012846:Singapore; D015996:Survival Rate; D044465:White People