title: Six-hour versus 12-hour protocols for AMI: CK-MB in conjunction with myoglobin.
abstract: The objective was to test the hypothesis that a protocol using myoglobin and creatine kinase-MB (CK-MB) can rapidly and safely exclude myocardial infarction (MI). The study used a prospective, convenience cohort of ED patients with clinically suspected myocardial ischemia. Myoglobin was measured on presentation, 2 and 6 hours later; CK-MB was measured on presentation, 6, 12, and 18 hours later. Of 519 patients, 76 (15%) had MIs, all of whom "ruled in" within 12 hours using a combination of myoglobin and CK-MB, for a sensitivity of 100% (95% CI, 95% to 100%), specificity of 92% (95% CI, 89% to 94%), LR (+) of 12 (95% CI, 9 to 16), and an LR (-) of 0.03 (95% CI, 0.0 to 0.05). Of the 76 patients with MIs, 73 ruled in with a 6 hour protocol, also using a combination of CK-MB and myoglobin, for a sensitivity of 96% (95% CI, 89% to 99%), specificity of 92% (95% CI, 89% to 94%), LR (+) of 11 (95% CI, 8 to 16), and an LR (-) of 0.04 (95% CI, 0.01 to 0.12). Our results support the hypothesis that, using an abbreviated protocol with CK-MB and myoglobin, MI can be reliably ruled out in ED patients with suspected ischemia.
authors.affiliation: Department of Emergency Medicine, Montefiore Medical Center, Teaching Hospital of the Albert Einstein College of Medicine, 111 East 210th Street, Bronx, NY 10467, USA. desses@montefiore.org
authors.forename: D
authors.initials: D
authors.lastname: Esses
authors.forename: E J
authors.initials: EJ
authors.lastname: Gallagher
authors.forename: R
authors.initials: R
authors.lastname: Iannaccone
authors.forename: P
authors.initials: P
authors.lastname: Bijur
authors.forename: V S
authors.initials: VS
authors.lastname: Srinivas
authors.forename: H
authors.initials: H
authors.lastname: Rose
authors.forename: L
authors.initials: L
authors.lastname: Kunkel
authors.forename: J
authors.initials: J
authors.lastname: Sokolof
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers; D004796:Clinical Enzyme Tests; D015331:Cohort Studies; D003402:Creatine Kinase / Q000097:blood*; D004562:Electrocardiography; D005260:Female; D006801:Humans; D007527:Isoenzymes / Q000097:blood; D016013:Likelihood Functions; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis*; D009211:Myoglobin / Q000097:blood*; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D013997:Time Factors
chemical_list: D015415:Biomarkers; D007527:Isoenzymes; D009211:Myoglobin; D003402:Creatine Kinase