title: Coronary artery calcium score prediction of all cause mortality and cardiovascular events in people with type 2 diabetes: systematic review and meta-analysis.
abstract: OBJECTIVE
  To investigate the association of coronary artery calcium score with all cause mortality and cardiovascular events in people with type 2 diabetes.
  
  
  METHODS
  Systematic review and meta-analysis of observational studies.
  
  
  METHODS
  Studies were identified from Embase, PubMed, and abstracts from the 2011 and 2012 annual meetings of the American Diabetes Association, European Association for the Study of Diabetes, American College of Cardiology, and American Heart Association (2011).
  
  
  METHODS
  Prospective studies that evaluated baseline coronary artery calcium score in people with type 2 diabetes and subsequent all cause mortality or cardiovascular events (fatal and non-fatal).
  
  
  METHODS
  Two independent reviewers extracted the data. The predictive value of the coronary artery calcium score was assessed by random effects model.
  
  
  RESULTS
  Eight studies were included (n=6521; 802 events; mean follow-up 5.18 years). The relative risk for all cause mortality or cardiovascular events, or both comparing a total coronary artery calcium score of ≥ 10 with a score of <10 was 5.47 (95% confidence interval 2.59 to 11.53; I(2)=82.4%, P<0.001). The overall sensitivity of a total coronary artery calcium score of ≥ 10 for this composite outcome was 94% (95% confidence interval 89% to 96%), with a specificity of 34% (24% to 44%). The positive and negative likelihood ratios were 1.41 (95% confidence interval 1.20 to 1.66) and 0.18 (0.10 to 0.30), respectively. For people with a coronary artery calcium score of <10, the post-test probability of the composite outcome was about 1.8%, representing a 6.8-fold reduction from the pretest probability. Four studies evaluated cardiovascular events as the outcome (n=1805; 351 events). The relative risk for cardiovascular events comparing a total coronary artery calcium score of ≥ 10 with a score of <10 was 9.22 (2.73 to 31.07; I(2)=76.7%, P=0.005). The positive and negative likelihood ratios were 1.67 (1.30 to 2.17) and 0.11 (0.04 to 0.29), respectively.
  
  
  CONCLUSIONS
  In people with type 2 diabetes, a coronary artery calcium score of ≥ 10 predicts all cause mortality or cardiovascular events, or both, and cardiovascular events alone, with high sensitivity but low specificity. Clinically, the finding of a coronary artery calcium score of <10 may facilitate risk stratification by enabling the identification of people at low risk within this high risk population.
authors.affiliation: Leadership Sinai Centre for Diabetes, Mount Sinai Hospital, 60 Murray Street, Suite L5-025, Mailbox-21, Toronto, ON, Canada M5T 3L9.
authors.forename: Caroline K
authors.initials: CK
authors.lastname: Kramer
authors.forename: Bernard
authors.initials: B
authors.lastname: Zinman
authors.forename: Jorge L
authors.initials: JL
authors.lastname: Gross
authors.forename: Luis H
authors.initials: LH
authors.lastname: Canani
authors.forename: Ticiana C
authors.initials: TC
authors.lastname: Rodrigues
authors.forename: Mirela J
authors.initials: MJ
authors.lastname: Azevedo
authors.forename: Ravi
authors.initials: R
authors.lastname: Retnakaran
mesh_terms: D002318:Cardiovascular Diseases / Q000453:epidemiology*; D002423:Cause of Death; D003331:Coronary Vessels / Q000000981:diagnostic imaging / Q000473:pathology*; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology* / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D011237:Predictive Value of Tests; D011859:Radiography; D012720:Severity of Illness Index; D061205:Vascular Calcification / Q000000981:diagnostic imaging / Q000453:epidemiology*