Abstract
Background Sequential changes in the hemodynamic effect of chronic epoprostenol therapy raise the following questions. Does an increase in cardiac output (CO) precede lowering of the pulmonary artery pressure (PAP) over the time course of improvement? What are the characteristics of good responders to chronic epoprostenol treatment? Method and Results Hemodynamics were evaluated by catheter examination. Most patients still alive after >1 year showed an increase in CO either with no change in mean PAP or accompanied by a decrease in mean PAP during increased dosing of epoprostenol. Immediately before cessation of the increase in epoprostenol dose in good responders, the ratio of total pulmonary resistance to total systemic resistance was low, and the pulmonary artery wedge pressure minus right atrial pressure was high compared with the newest data in poor responders. One year after fixing at the best dose of epoprostenol, the mean PAP further decreased. Conclusions In good responders, pulmonary selectivity to epoprostenol is high, and the blood returning to the left-sided heart through the pulmonary circulation increases. Hemodynamics further improve, even after fixing at the best dose of epoprostenol. The present data did not show that an increase in CO precedes lowering of the PAP over the course of improvement.
