title: Hemodynamic changes determine the efficacy of thrombolysis: results from an in-vitro flow model.
abstract: BACKGROUND
  The efficacy of thrombolytic therapy might be influenced by changes in the hemodynamic status. The aim of the study was to examine whether changes in perfusion pressure could affect the time to reflow in an in-vitro model.
  
  
  METHODS
  The in-vitro flow system comprised flexible plastic tubes that enclosed a blood clot formed in one of the circuit arms. Streptokinase (125,000 U) or saline (control) was injected from a proximal side branch to induce thrombolysis. The protocol comprised four treatments: A, perfusion pressure 150/90 mmHg with streptokinase infusion; B, perfusion pressure 150/90 mmHg with saline; C, perfusion pressure 120/60 mmHg with streptokinase; D, perfusion pressure 120/60 mmHg with saline. Reflow was defined as flow restoration determined by the ultrasonic flowmeter.
  
  
  RESULTS
  Successful recanalization was obtained in six of six samples subjected to treatment A (100%), two of seven samples subjected to treatment B (28%), three of five samples subjected to treatment C (60%) and none of six samples subjected to treatment D (0%). Time to reflow was 23 +/- 11 min with treatment A, 76 +/- 24 min with treatment B, 66 +/- 25 min with treatment C, and > 90 min with treatment D.
  
  
  CONCLUSIONS
  Our data suggest that the hemodynamic status determines the efficacy of streptokinase-induced thrombolysis, and that spontaneous clot lysis is more likely to occur at greater perfusion pressures. It is conceivable that the hypotensive reaction induced by streptokinase in the clinical setting may adversely affect angiographic patency, compared with that observed with other lytic agents such as tissue-type plasminogen activator.
authors.affiliation: Department of Cardiology, Tel Aviv Medical Center, Israel.
authors.forename: R
authors.initials: R
authors.lastname: Kornowski
authors.forename: L
authors.initials: L
authors.lastname: Mendelevich
authors.forename: U
authors.initials: U
authors.lastname: Zaretsky
authors.forename: S
authors.initials: S
authors.lastname: Einav
authors.forename: S
authors.initials: S
authors.lastname: Laniado
authors.forename: G
authors.initials: G
authors.lastname: Keren
mesh_terms: D001794:Blood Pressure / Q000502:physiology; D003326:Coronary Circulation / Q000187:drug effects / Q000502:physiology*; D003328:Coronary Thrombosis / Q000188:drug therapy* / Q000503:physiopathology; D005343:Fibrinolytic Agents / Q000494:pharmacology*; D006801:Humans; D008955:Models, Cardiovascular; D013300:Streptokinase / Q000494:pharmacology*; D015912:Thrombolytic Therapy
chemical_list: D005343:Fibrinolytic Agents; D013300:Streptokinase