title: Prognostic Value of Coronary Artery Calcium Score in Acute Chest Pain Patients Without Known Coronary Artery Disease: Systematic Review and Meta-analysis.
abstract: Coronary artery calcium score (CACS) is a well-established test for risk stratifying asymptomatic patients. Recent studies also indicate that CACS may accurately risk stratify stable patients presenting to the emergency department (ED) with acute chest pain; however, many were underpowered. The purpose of this systematic review and meta-analysis is to evaluate the prognostic value and accuracy of a zero (normal) CACS for identifying patients at acceptable low risk for future cardiovascular events who might be safely discharged home from the ED.
  
  
  
  We searched multiple databases for longitudinal studies of CACS in symptomatic patients without known coronary artery disease that reported major adverse cardiovascular events (MACEs), including death and myocardial infarction. Pooled risk ratios, sensitivity, specificity, and likelihood ratios were analyzed.
  
  
  
  Eight studies evaluated 3,556 patients, with a median follow-up of 10.5 months. Pooled prevalence of zero CACS was 60%. Patients with CACS=0 had a significantly lower risk of cardiovascular events compared with those with CACS greater than 0 (MACEs: relative risk 0.06, 95% confidence interval 0.04 to 0.11, I2=0%; death/myocardial infarction: relative risk 0.19; 95% confidence interval 0.08 to 0.47, I2=0%). The pooled event rates for CACS=0 (MACEs 0.8%/year; death/myocardial infarction 0.5%/year) were significantly lower than for CACS greater than 0 (MACEs 14.6%/year; death/myocardial infarction 3.5%/year). Analysis of summary testing parameters showed a sensitivity of 96%, specificity of 60%, positive likelihood ratio of 2.36, and negative likelihood ratio of 0.07.
  
  
  
  Acute chest pain patients without history of coronary artery disease, ischemic ECG changes, or increased cardiac enzyme levels commonly have a CACS of zero, with a very low subsequent risk of MACEs or death or myocardial infarction. This meta-analysis proffers the potential role of initial CACS testing for avoiding unnecessary hospitalization and further cardiac testing in acute chest pain patients with a CACS of zero.
authors.affiliation: Heart and Vascular Center, University of Iowa Hospital, Iowa City, IA.
authors.forename: Kongkiat
authors.initials: K
authors.lastname: Chaikriangkrai
authors.affiliation: Heart and Vascular Center, University of Iowa Hospital, Iowa City, IA.
authors.forename: Ghanshyam
authors.initials: G
authors.lastname: Palamaner Subash Shantha
authors.affiliation: Department of Medicine, University of Kansas Medical Center, Kansas City, KS.
authors.forename: Hye Yeon
authors.initials: HY
authors.lastname: Jhun
authors.affiliation: Department of Medicine, Mayo Clinic, Rochester, MN.
authors.forename: Patompong
authors.initials: P
authors.lastname: Ungprasert
authors.affiliation: Heart and Vascular Center, University of Iowa Hospital, Iowa City, IA.
authors.forename: Gardar
authors.initials: G
authors.lastname: Sigurdsson
authors.affiliation: Houston Methodist DeBakey Heart and Vascular Center, Houston, TX.
authors.forename: Faisal
authors.initials: F
authors.lastname: Nabi
authors.affiliation: Houston Methodist DeBakey Heart and Vascular Center, Houston, TX.
authors.forename: John J
authors.initials: JJ
authors.lastname: Mahmarian
authors.affiliation: Houston Methodist DeBakey Heart and Vascular Center, Houston, TX. Electronic address: smchang@houstonmethodist.org.
authors.forename: Su Min
authors.initials: SM
authors.lastname: Chang
mesh_terms: D002118:Calcium / Q000032:analysis*; D002637:Chest Pain / Q000175:diagnosis* / Q000209:etiology; D003324:Coronary Artery Disease / Q000150:complications / Q000175:diagnosis*; D003331:Coronary Vessels / Q000737:chemistry*; D004636:Emergency Service, Hospital; D006801:Humans; D011379:Prognosis
chemical_list: D002118:Calcium