Efficacy of streptokinase, but not tissue-type plasminogen activator, in achieving 90-minute patency after thrombolysis for acute myocardial infarction decreases with time to treatment. PERM Study Group. Prospective Evaluation of Reperfusion Markers

J Am Coll Cardiol. 1998 Mar 15;31(4):776-9. doi: 10.1016/s0735-1097(98)00018-7.


Objectives: We sought to examine the relation between time to treatment and 90-min patency rates in patients receiving intravenous streptokinase (SK) or accelerated tissue-type plasminogen activator (t-PA).

Background: Early patency of the infarct-related artery is a major determinant of survival after thrombolysis for acute myocardial infarction. Some data suggest that time to treatment may influence the efficacy of nonfibrin-specific thrombolytic agents in restoring early patency of the infarct-related vessel.

Methods: We performed a retrospective analysis of a cohort of 481 patients receiving thrombolytic therapy for acute myocardial infarction <6 h after pain onset, all of whom underwent 90-min coronary angiography. Patency of the infarct-related artery was graded by two observers who had no knowledge of the treatment received or the time between pain and therapy.

Results: There was no difference in baseline clinical or angiographic characteristics according to the timing or nature of treatment. Thrombolysis in Myocardial Infarction (TIMI) flow grade 2 or 3 patency rate after SK correlated negatively with the time between onset of pain and thrombolysis (r = 0.8, p = 0.05), whereas the 90-min patency rate after t-PA appeared stable as a function of time to treatment. When patients were categorized as having received treatment <3 or > or = 3 h after pain onset, the patency rate was similar with t-PA, but significantly higher when SK was administered early rather than late, regardless of whether TIMI flow grades 2 and 3 were pooled (86.9% vs. 59.4%, p = 0.0001) or TIMI flow grade 3 alone was considered to indicate patency (81.7% vs. 53.6%, p = 0.0001). Multivariate logistic regression analysis showed a negative effect of time to treatment on the patency probability for SK (p = 0.0001) but not for t-PA.

Conclusions: The efficacy of streptokinase but not t-PA in restoring early coronary patency after intravenous thrombolysis is markedly lower when patients are treated later after onset of pain.

Publication types

  • Comparative Study

MeSH terms

  • Coronary Angiography
  • Female
  • Fibrinolytic Agents / therapeutic use*
  • Humans
  • Logistic Models
  • Male
  • Middle Aged
  • Multivariate Analysis
  • Myocardial Infarction / diagnostic imaging
  • Myocardial Infarction / drug therapy*
  • Myocardial Infarction / physiopathology
  • Myocardial Reperfusion
  • Plasminogen Activators / therapeutic use
  • Retrospective Studies
  • Streptokinase / therapeutic use*
  • Thrombolytic Therapy*
  • Time Factors
  • Tissue Plasminogen Activator / therapeutic use*
  • Vascular Patency*


  • Fibrinolytic Agents
  • Streptokinase
  • Plasminogen Activators
  • Tissue Plasminogen Activator