title: Coronary artery calcium score as a predictor for incident stroke: Systematic review and meta-analysis.
abstract: BACKGROUND
  Coronary artery calcium score (CACS) is a well-established test for risk stratifying asymptomatic patients for overall cardiovascular or coronary events. However; the prognostic value for incident stroke remains controversial. The objective of this study was to investigate the predictive value of CACS obtained by non-contrast electrocardiogram-gated computed tomography for incident stroke.
  
  
  METHODS
  We searched PubMed, EMBASE, Cochrane databases for prospective longitudinal studies of CACS which reported the incidence of stroke. Incidence of stroke was compared in patients with and without coronary calcification.
  
  
  RESULTS
  Three studies evaluated 13,262 asymptomatic patients (mean age=60years, 50% men) without apparent cardiovascular diseases. During a follow-up of 7.2years (median 5years, range 4.4-9.5years, 95,434patient-years), the overall pooled incidence of stroke was 0.26%/year. The pooled risk ratio of CACS>0 for incident stroke was 2.95 (95% CI: 2.18-4.01, p<0.001) compared to CACS=0. The heterogeneity among studies was low (I2=0%). The pooled incidence rate of stroke categorized by CACS was 0.12%/year for CACS 0, 0.26%/year for CACS 1-99, 0.41%/year for CACS 100-399 and 0.70%/year for CACS ≥400.
  
  
  CONCLUSIONS
  In asymptomatic patients without apparent cardiovascular diseases, the incidence of stroke was overall low. The presence and severity of coronary artery calcification were associated with incident stroke over mid-long term follow-up.
authors.affiliation: University of Iowa Hospital: Heart and Vascular Center, United States. Electronic address: supersoon@gmail.com.
authors.forename: Kongkiat
authors.initials: K
authors.lastname: Chaikriangkrai
authors.affiliation: Department of Medicine, University of Kansas Medical Center, United States.
authors.forename: Hye Yeon
authors.initials: HY
authors.lastname: Jhun
authors.affiliation: University of Iowa Hospital: Heart and Vascular Center, United States.
authors.forename: Ghanshyam
authors.initials: G
authors.lastname: Palamaner Subash Shantha
authors.affiliation: University of Iowa Hospital: Heart and Vascular Center, United States.
authors.forename: Aref
authors.initials: A
authors.lastname: Bin Abdulhak
authors.affiliation: University of Iowa Hospital: Heart and Vascular Center, United States.
authors.forename: Gardar
authors.initials: G
authors.lastname: Sigurdsson
authors.affiliation: Houston Methodist DeBakey Heart & Vascular Center, United States.
authors.forename: Faisal
authors.initials: F
authors.lastname: Nabi
authors.affiliation: Houston Methodist DeBakey Heart & Vascular Center, United States.
authors.forename: John J
authors.initials: JJ
authors.lastname: Mahmarian
authors.affiliation: Houston Methodist DeBakey Heart & Vascular Center, United States.
authors.forename: Su Min
authors.initials: SM
authors.lastname: Chang
mesh_terms: D003324:Coronary Artery Disease / Q000175:diagnosis* / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D064887:Observational Studies as Topic / Q000379:methods; D011237:Predictive Value of Tests; D012720:Severity of Illness Index; D020521:Stroke / Q000175:diagnosis* / Q000453:epidemiology; D061205:Vascular Calcification / Q000175:diagnosis* / Q000453:epidemiology
keywords: Calcium score; Cerebrovascular disease; Computed angiography; Coronary artery disease; Coronary calcification; Stroke