EFFECTS OF LONG-TERM INFUSION OF PROSTACYCLIN (EPOPROSTENOL) ON ECHOCARDIOGRAPHIC MEASURES OF RIGHT-VENTRICULAR STRUCTURE AND FUNCTION IN PRIMARY PULMONARY-HYPERTENSION

Background Right heart failure is an important cause of morbidity and mortality in primary pulmonary hypertension. In a recent prospective, randomized study of severely symptomatic patients, treatment with pros tacyclin (epoprostenol) produced improvements in hemodynamics, quality of life, and survival. This article describes the echocardiographic c haracteristics of participants in this trial; the relationships of ech ocardiographic variables to hemodynamic parameters, exercise capacity, and quality of life; and the echocardiographic changes associated wit h prostacyclin therapy. Methods and Results The 81 patients enrolled i n this multicenter trial were randomized to treatment with a long-term infusion of prostacyclin in addition to conventional therapy (n=41) o r conventional therapy alone (n=40) for 12 weeks. Echocardiograms and assessments of hemodynamics, exercise capacity, and quality of life we re performed before and after the treatment phase. On baseline evaluat ion, patients had marked right ventricular dilatation and dysfunction, abnormal septal curvature, and significant tricuspid regurgitation wi th a high regurgitant velocity. Pericardial effusions were common. Mor e pronounced abnormalities in right heart structure and function were associated with higher pulmonary arterial and mean right atrial pressu res, lower cardiac index, and impaired exercise capacity but had no pr edictable relationship to quality-of-life indicators. The 12-week infu sion of prostacyclin had beneficial effects on right ventricular size, curvature of the interventricular septum, and maximal tricuspid regur gitant jet velocity. Conclusions The echocardiographic manifestations of severe primary pulmonary hypertension reflect abnormalities in hemo dynamics and exercise capacity. Prostacyclin has beneficial effects on right heart structure and function that may contribute to the clinica l improvement and prolonged survival observed with this drug.