title: Importance of effective, early and sustained reperfusion during acute myocardial infarction.
abstract: The determinants of myocardial salvage after thrombolytic therapy during acute myocardial infarction (AMI) have not been clearly defined. In 1984, a prospective randomized trial was undertaken to define the relations between delay to treatment and effectiveness of perfusion to salvage of myocardium. Patients presenting within 2 hours of symptom onset received intravenous streptokinase immediately (group 1, 20 patients) or 5 hours after symptom onset (group 2, 16 patients). Effective perfusion (less than or equal to 90% residual stenosis with rapid distal runoff) occurred in 63% of patients in both groups. Five patients, all in group 1, had recurrent AMI; 4 of the 5 had effective perfusion. There was no group difference in left ventricular ejection fraction at baseline or before discharge. However, group 1 patients with effective perfusion tended to have a greater predischarge mean ejection fraction than those in group 1 with ineffective perfusion (53 +/- 13 vs 44 +/- 16%, p less than 0.10) and had a greater mean value than those in group 2 with ineffective perfusion (53 +/- 13 vs 38 +/- 17%, p less than 0.03). The ejection fraction did not change significantly between admission and discharge in either group, but it increased significantly in group 1 patients with effective perfusion and no recurrent AMI (delta EF = +6 +/- 8%, p less than 0.04). Group 1 patients with ineffective perfusion had a significant decrease in ejection fraction (delta EF = -4 +/- 4%, p less than 0.04). In group 2 patients the ejection fraction did not change, regardless of the state of perfusion.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Medicine, University of Calgary, Alberta, Canada.
authors.forename: I
authors.initials: I
authors.lastname: Belenkie
authors.forename: C R
authors.initials: CR
authors.lastname: Thompson
authors.forename: D E
authors.initials: DE
authors.lastname: Manyari
authors.forename: M L
authors.initials: ML
authors.lastname: Knudtson
authors.forename: H J
authors.initials: HJ
authors.lastname: Duff
authors.forename: M C
authors.initials: MC
authors.lastname: Poon
authors.forename: E R
authors.initials: ER
authors.lastname: Smith
mesh_terms: D000368:Aged; D002986:Clinical Trials as Topic; D003402:Creatine Kinase / Q000097:blood; D005260:Female; D006801:Humans; D007527:Isoenzymes; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000188:drug therapy* / Q000201:enzymology / Q000503:physiopathology; D015425:Myocardial Reperfusion; D011897:Random Allocation; D013300:Streptokinase / Q000627:therapeutic use; D013318:Stroke Volume; D013997:Time Factors
chemical_list: D007527:Isoenzymes; D003402:Creatine Kinase; D013300:Streptokinase