title: Ventricular function and infarct size: the Western Washington Intravenous Streptokinase in Myocardial Infarction Trial.
abstract: The Western Washington Intravenous Streptokinase in Acute Myocardial Infarction Trial randomized 368 patients with symptoms and signs of acute myocardial infarction of less than 6 h duration to either conventional care or 1.5 million units of intravenous streptokinase. The mean time to randomization was 209 min and 52% of patients were randomized within 3 h of symptom onset. Quantitative, tomographic thallium-201 infarct size and radionuclide ejection fraction were measured at 8.2 +/- 7.5 weeks in 207 survivors who lived within a 100 mile radius of a centralized laboratory. Overall, infarct size as a percent of the left ventricle was 19 +/- 13% for control subjects and 15 +/- 13% for treatment patients (p = 0.03). For anterior infarction in patients entered within 3 h of symptom onset, infarct size was 28 +/- 13% in the control group versus 19 +/- 15% for the treatment group (p = 0.09). Left ventricular ejection fraction was 47 +/- 15% in the control versus 51 +/- 15% in the treatment group (p = 0.08). For anterior infarction of less than 3 h duration, the ejection fraction was 38 +/- 16% in the control versus 48 +/- 20% in the treatment group (p = 0.13). By statistical analysis incorporating the nonsurvivors, p values for all of these variables were less than or equal to 0.08. There was no benefit for patients with inferior infarction or for anterior infarction of greater than 3 h duration. It is concluded that intravenous streptokinase, when given within 3 h of symptom onset to patients with anterior infarction, reduces infarct size and improves ventricular function.
authors.affiliation: Department of Medicine, Veterans Administration Medical Center, Seattle, Washington.
authors.forename: J L
authors.initials: JL
authors.lastname: Ritchie
authors.forename: M
authors.initials: M
authors.lastname: Cerqueira
authors.forename: C
authors.initials: C
authors.lastname: Maynard
authors.forename: K
authors.initials: K
authors.lastname: Davis
authors.forename: J W
authors.initials: JW
authors.lastname: Kennedy
mesh_terms: D002986:Clinical Trials as Topic; D003331:Coronary Vessels / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology; D006321:Heart / Q000000981:diagnostic imaging; D006801:Humans; D007262:Infusions, Intravenous; D009203:Myocardial Infarction / Q000188:drug therapy* / Q000473:pathology / Q000503:physiopathology; D011877:Radionuclide Imaging; D011897:Random Allocation; D013300:Streptokinase / Q000008:administration & dosage*; D013318:Stroke Volume; D013794:Thallium Radioisotopes
chemical_list: D013794:Thallium Radioisotopes; D013300:Streptokinase