HEMODYNAMIC-CHANGES DETERMINE THE EFFICACY OF THROMBOLYSIS - RESULTS FROM AN IN-VITRO FLOW MODEL

Background The efficacy of thrombolytic therapy might be influenced by changes in the hemodynamic status. The aim of the study was to examin e whether changes in perfusion pressure could affect the time to reflo w in an in-vitro model. Methods The in-vitro flow system comprised fle xible plastic tubes that enclosed a blood clot formed in one of the ci rcuit arms, Streptokinase (125 000 U) or saline (control) was injected from a proximal side branch to induce thrombolysis, The protocol comp rised four treatments: A, perfusion pressure 150/90 mmHg with streptok inase infusion; B, perfusion pressure 150/90 mmHg with saline; C, perf usion pressure 120/60 mmHg with streptokinase; D, perfusion pressure 1 20/60 mmHg with saline. Reflow was defined as flow restoration determi ned by the ultrasonic flowmeter. Results Successful recanalization was obtained in six of six samples subjected to treatment A (100%), two o f seven samples subjected to treatment B (28%), three of five samples subjected to treatment C (60%) and none of six samples subjected to tr eatment 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 hemodynami c: status determines the efficacy of streptokinase-induced thrombolysi s, and that spontaneous clot lysis is more likely to occur at greater perfusion pressures. It is conceivable that the hypotensive reaction i nduced by streptokinase in the clinical setting may adversely affect a ngiographic patency, compared with that observed with other lytic agen ts such as tissue-type plasminogen activator. (C) 1998 Lippincott-Rave n Publishers.