title: Suboptimal anticoagulation with pre-hospital heparin in ST-elevation myocardial infarction.
abstract: This is a prospective, observational study performed in all consecutive ST-elevation myocardial infarction (STEMI) patients who had activated clotting time (ACT) measurement on arrival in the cathlab before coronary angiography. We studied the therapeutic effects of a pre-hospital fixed heparin bolus dose in consecutive patients with STEMI. A total of 1,533 patients received pre-hospital administration of aspirin, high dose clopidogrel (600 mg) and a fixed bolus dose of 5,000 IU unfractionated heparin (UFH), according to the national ambulance protocols. Some patients were also treated with glycoprotein IIb/IIIa inhibitors (GPI) in the ambulance. A therapeutic ACT range was defined according to the ESC guidelines as 200-250 seconds when patients had GPI pre-treatment and 250-350 seconds when no GPI pre-treatment. Of the 1,533 patients, 216 patients (14.1%) had an ACT within the therapeutic range, 82.3% of the patients had a too low ACT, whereas 3.5% of the patients had a too high ACT. After multivariable analysis, the only independent predictor of a too low ACT was increasing weight (odds ratio 1.02/kg, 95% confidence interval 1.01-1.03, p=0.001). Patients with a too low ACT had less often an open infarct related vessel (initial TIMI flow 2,3) as compared to patients with an ACT in range (36.5% vs. 45.9%, p=0.013). In only a minority of patients with STEMI, pre-hospital treatment with a fixed bolus dose UFH is within the therapeutic ACT range. Increased weight is an independent determinant of a too low ACT. We strongly recommend weight adjusted administration of UFH in the ambulance.
authors.affiliation: Isala Klinieken, Department of Cardiology, Groot Wezenland 20, 8011JW Zwolle, The Netherlands.
authors.forename: Renicus S
authors.initials: RS
authors.lastname: Hermanides
authors.forename: Jan Paul
authors.initials: JP
authors.lastname: Ottervanger
authors.forename: Jan-Henk E
authors.initials: JH
authors.lastname: Dambrink
authors.forename: Menko-Jan
authors.initials: MJ
authors.lastname: de Boer
authors.forename: Jan C A
authors.initials: JC
authors.lastname: Hoorntje
authors.forename: A T Marcel
authors.initials: AT
authors.lastname: Gosselink
authors.forename: Harry
authors.initials: H
authors.lastname: Suryapranata
authors.forename: Felix
authors.initials: F
authors.lastname: Zijlstra
authors.forename: Arnoud W J
authors.initials: AW
authors.lastname: van 't Hof
mesh_terms: D000368:Aged; D001835:Body Weight; D003955:Diagnostic Tests, Routine / Q000379:methods; D054796:Drug Dosage Calculations; D004562:Electrocardiography; D004632:Emergency Medical Services; D005260:Female; D006493:Heparin / Q000008:administration & dosage / Q000009:adverse effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000188:drug therapy / Q000503:physiopathology; D017410:Practice Guidelines as Topic; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D014914:Whole Blood Coagulation Time
chemical_list: D006493:Heparin