title: Evolution of early TIMI 2 flow after thrombolysis for acute myocardial infarction. GUSTO-1 Angiographic Investigators.
abstract: BACKGROUND
  Patients with early Thrombolysis in Myocardial Infarction (TIMI) grade 2 flow after thrombolysis appear to have outcomes similar to thrombolytic failures. To evaluate the origin and evolution of early TIMI 2 flow, we examined early and late angiographic and ventriculographic data from the Global Utilization of Streptokinase and TPA for Occluded Arteries (GUSTO-1) angiographic study.
  
  
  RESULTS
  Of the 914 patients with both 90-minute and 5- to 7-day catheterizations, 278 patients had TIMI grade 2 flow at 90 minutes. At follow-up, 188 (67%) had improved to TIMI grade 3 flow. At 90 minutes, patients with TIMI grade 2 flow had greater infarct vessel narrowing and a significantly greater incidence of thrombus than patients with TIMI grade 3 flow. At the 5- to 7-day follow-up, patients whose flow had improved from TIMI grade 2 at 90 minutes to grade 3 flow at follow-up had larger-caliber vessels (minimum luminal diameter, 0.99 +/- 0.47 versus 0.84 +/- 0.48 mm; P = .03) and a lower incidence of visible thrombus (26% versus 38%, P = .04) than those with persistent TIMI grade 2 flow. These patients also had a higher mean ejection fraction (57.5 +/- 14.1% versus 52.8 +/- 12.9%, P = .02) and better infarct zone wall motion (-2.1 +/- 1.5 versus -2.6 +/- 1.3 SD per chord, P = .01) at the 5- to 7-day follow-up. Patients in whom flow improved from TIMI grade 2 at 90 minutes to TIMI grade 3 by 5 to 7 days had significantly better left ventricular function than patients with persistent TIMI grade 0, 1, or 2 flow and constituted a group whose left ventricular function was intermediate between those who had no reperfusion (TIMI grades 0 and 1) and those whose reperfusion was complete (TIMI grade 3).
  
  
  CONCLUSIONS
  These data suggest that incomplete clot lysis plays a significant role in the pathogenesis of TIMI grade 2 flow. Furthermore, early TIMI grade 2 flow may be sufficient to provide prolonged myocyte viability, which will further recover if flow normalizes.
authors.affiliation: Division of Cardiology, George Washington University, Washington, DC 20037, USA. jsreiner@gwis2.circ.gwu.edu
authors.forename: J S
authors.initials: JS
authors.lastname: Reiner
authors.forename: C F
authors.initials: CF
authors.lastname: Lundergan
authors.forename: A
authors.initials: A
authors.lastname: Fung
authors.forename: K
authors.initials: K
authors.lastname: Coyne
authors.forename: S
authors.initials: S
authors.lastname: Cho
authors.forename: N
authors.initials: N
authors.lastname: Israel
authors.forename: J
authors.initials: J
authors.lastname: Kazmierski
authors.forename: G
authors.initials: G
authors.lastname: Pilcher
authors.forename: J
authors.initials: J
authors.lastname: Smith
authors.forename: S
authors.initials: S
authors.lastname: Rohrbeck
authors.forename: M
authors.initials: M
authors.lastname: Thompson
authors.forename: F
authors.initials: F
authors.lastname: Van de Werf
authors.forename: A M
authors.initials: AM
authors.lastname: Ross
mesh_terms: D000368:Aged; D017023:Coronary Angiography; D003326:Coronary Circulation / Q000187:drug effects*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000188:drug therapy* / Q000503:physiopathology*; D015912:Thrombolytic Therapy; D013997:Time Factors; D016276:Ventricular Function