title: Outcomes and radiation exposure of emergency department patients with chest pain and shortness of breath and ultralow pretest probability: a multicenter study.
abstract: OBJECTIVE
  Excessive radiation exposure remains a concern for patients with symptoms suggesting acute coronary syndrome and pulmonary embolism but must be judged in the perspective of pretest probability and outcomes. We quantify and qualify the pretest probability, outcomes, and radiation exposure of adults with both chest pain and dyspnea.
  
  
  METHODS
  This was a prospective, 4-center, outcomes study. Patients were adults with dyspnea and chest pain, nondiagnostic ECGs, and no obvious diagnosis. Pretest probability for both acute coronary syndrome and pulmonary embolism was assessed with a validated method; ultralow risk was defined as pretest probability less than 2.5% for both acute coronary syndrome and pulmonary embolism. Patients were followed for diagnosis and total medical radiation exposure for 90 days.
  
  
  RESULTS
  Eight hundred forty patients had complete data; 23 (3%) had acute coronary syndrome and 15 (2%) had pulmonary embolism. The cohort received an average of 4.9 mSv radiation to the chest, 48% from computed tomography pulmonary angiography. The pretest probability estimates for acute coronary syndrome and pulmonary embolism were less than 2.5% in 227 patients (27%), of whom 0 of 277 (0%; 95% confidence interval 0% to 1.7%) had acute coronary syndrome or pulmonary embolism and 7 of 227 (3%) had any significant cardiopulmonary diagnosis. The estimated chest radiation exposure per patient in this ultralow-risk group was 3.5 mSv, including 26 (3%) with greater than 5 mSv radiation to the chest and no significant cardiopulmonary diagnosis.
  
  
  CONCLUSIONS
  One quarter of patients with chest pain and dyspnea had ultralow risk and no acute coronary syndrome or pulmonary embolism but were exposed to an average of 3.5 mSv radiation to the chest. These data can be used in a clinical guideline to reduce radiation exposure.
authors.affiliation: Department of Emergency Medicine, Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, IN. Electronic address: jefkline@iupui.edu.
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Kline
authors.affiliation: Department of Emergency Medicine and Center for Vascular Biology Research, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA.
authors.forename: Nathan I
authors.initials: NI
authors.lastname: Shapiro
authors.affiliation: Department Emergency Medicine, University of Mississippi Medical Center, Jackson, MS.
authors.forename: Alan E
authors.initials: AE
authors.lastname: Jones
authors.affiliation: Department of Emergency Medicine, Carolinas Medical Center, Charlotte, NC.
authors.forename: Jackeline
authors.initials: J
authors.lastname: Hernandez
authors.affiliation: Department of Emergency Medicine, Carolinas Medical Center, Charlotte, NC.
authors.forename: Melanie M
authors.initials: MM
authors.lastname: Hogg
authors.affiliation: Department of Economics, UNC Charlotte, Charlotte, NC.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Troyer
authors.affiliation: Department of Emergency Medicine, Wake Forest University School of Medicine, Winston-Salem, NC.
authors.forename: R Darrell
authors.initials: RD
authors.lastname: Nelson
mesh_terms: D054058:Acute Coronary Syndrome / Q000150:complications / Q000175:diagnosis / Q000000981:diagnostic imaging; D000328:Adult; D000792:Angiography / Q000706:statistics & numerical data; D002637:Chest Pain / Q000000981:diagnostic imaging* / Q000209:etiology; D004417:Dyspnea / Q000000981:diagnostic imaging* / Q000209:etiology; D004562:Electrocardiography; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D063868:Patient Outcome Assessment; D011336:Probability; D011446:Prospective Studies; D011655:Pulmonary Embolism / Q000150:complications / Q000175:diagnosis / Q000000981:diagnostic imaging; D011829:Radiation Dosage; D013902:Radiography, Thoracic / Q000706:statistics & numerical data; D012307:Risk Factors; D014057:Tomography, X-Ray Computed / Q000706:statistics & numerical data