The comparatively poor response with the combination therapy may have been due to an increase in hepatic blood flow with Iloprost and secondary accelerated clearance of rtPA.
While the current study demonstrated that an increase in cardiac output per se markedly enhanced or potentiated rtPA induced pulmonary thrombolysis, a relatively low dose of rtPA was employed. As cited above, previous studies employing the same model have demonstrated that 1 mg/kg given over 15 min may result in the maximum rate and extent of thrombolysis with rtPA.
In all of these studies, cardiac output was low following pulmonary embolization and remained low during and after rtPA therapy. Accordingly, it is conceivable that an increase in cardiac output could also augment the rate and extent of pulmonary thrombolysis obtained with a higher or otherwise “maximum effective” dose of rtPA. On the other hand, if an increase in CO can be demonstrated to augment rtPA induced thrombolysis in patients, this would also permit a lowering of the total dose of rtPA. Clearly, further studies are required to test these possibilities. proventil inhaler
Since our results were obtained in an anesthetized canine preparation with exogenously produced autologous blood clots, we stress caution in applying these results directly to patients.