Hyperthermic fibrinolysis with rt-PA: in vitro results.

<bold>Purpose: </bold>To investigate the influence of hyperthermia up to 45 degrees C on fibrinolysis with recombinant tissue-type plasminogen activator (rt-PA).<bold>Methods: </bold>Standardized fibrin clots were incubated in a water bath for 5 hr with either rt-PA (test group) or 0.9% sodium chloride (control group) and blood plasma at temperatures of 30-45 degrees C. Concentrations of D-dimer and time to complete clot lysis were measured.<bold>Results: </bold>The activity of fibrinolysis with rt-PA rose with increasing temperature: time to lysis approximately halved from 30 degrees C to 40 degrees C and the concentration of D-dimer tripled. In the control group clot size did not change.<bold>Conclusions: </bold>Activity of rt-PA-induced fibrinolysis rises distinctly with higher temperatures. Since even healthy subjects show a physiologic decline in body temperature in the extremities, in patients with occlusive arterial disease decreased activity of fibrinolysis with rt-PA can be expected. Controlled hyperthermia may improve fibrinolysis with rt-PA and should be investigated in vivo. [ABSTRACT FROM AUTHOR]