title: Prognostic significance of ST segment shift early after resolution of ST elevation in patients with myocardial infarction treated with thrombolytic therapy: the GUSTO-I ST Segment Monitoring Substudy.
abstract: OBJECTIVE
  We sought to study the relation between recurrent ST segment shift within 6 to 24 h of initial resolution of ST elevation after thrombolytic therapy and 30-day and 1-year mortality.
  
  
  BACKGROUND
  Rapid and stable resolution of ST segment elevation in relation to thrombolytic therapy in patients with an acute myocardial infarction is an indicator of culprit artery patency. Whether recurrence of ST segment shift during continuous ST monitoring after initial resolution is related to poor prognosis has not been studied.
  
  
  METHODS
  ST segment monitoring was performed within 30 min after thrombolytic therapy for acute myocardial infarction. The predictive value of a new ST segment shift (assessed as > or = 0.1-mV deviation from the baseline) 6 to 24 h after thrombolytic therapy was studied with respect to 30-day and 1-year mortality.
  
  
  RESULTS
  Of 734 patients, 243 had a new ST segment shift (33%). The 30-day mortality rate in patients with an ST shift (7.8%) was significantly higher than that in patients without an ST shift (2.25%, p = 0.001), as was the 1-year mortality rate (10.3% vs. 5.7%, respectively, p = 0.025). Multivariable analysis revealed an independent predictive value of ST shift with respect to 30-day mortality (p = 0.008), even after consideration of multiple clinical risk factors in the overall Global Utilization of Streptokinase and TPA for Occluded Coronary Arteries (GUSTO)-I mortality model (p = 0.0001). Moreover, the duration of the ST shift bore a direct relation with 1-year mortality (p = 0.008).
  
  
  CONCLUSIONS
  Detection of ST segment shift early after thrombolytic therapy for acute myocardial infarction is a simple, noninvasive means of identifying patients at high risk and is superior to other commonly assessed clinical risk factors. Thus, patients with a new ST shift after the first 6 h, but within 24 h, represent a high risk group that may benefit from more aggressive intervention, whereas patients without evidence of an ST shift represent a low risk subgroup.
authors.affiliation: Division of Cardiology, St. Michael's Hospital, University of Toronto, Ontario, Canada.
authors.forename: A
authors.initials: A
authors.lastname: Langer
authors.forename: M W
authors.initials: MW
authors.lastname: Krucoff
authors.forename: P
authors.initials: P
authors.lastname: Klootwijk
authors.forename: M L
authors.initials: ML
authors.lastname: Simoons
authors.forename: C B
authors.initials: CB
authors.lastname: Granger
authors.forename: A
authors.initials: A
authors.lastname: Barr
authors.forename: R M
authors.initials: RM
authors.lastname: Califf
authors.forename: P W
authors.initials: PW
authors.lastname: Armstrong
mesh_terms: D004562:Electrocardiography; D005260:Female; D005343:Fibrinolytic Agents / Q000627:therapeutic use; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000188:drug therapy / Q000401:mortality* / Q000503:physiopathology; D011379:Prognosis; D016032:Randomized Controlled Trials as Topic; D012307:Risk Factors; D013300:Streptokinase / Q000627:therapeutic use; D015996:Survival Rate; D015912:Thrombolytic Therapy; D013997:Time Factors; D010959:Tissue Plasminogen Activator / Q000627:therapeutic use
chemical_list: D005343:Fibrinolytic Agents; D013300:Streptokinase; D010959:Tissue Plasminogen Activator