SAFETY AND EFFICACY OF A NEW TRANSPULMONARY ECHO CONTRAST AGENT IN ECHOCARDIOGRAPHIC STUDIES IN PATIENTS

Objectives. This study was designed to investigate in patients the eff ect of a new transpulmonary echo contrast agent, made from 5% human se rum albumin (Albunex), on systemic and pulmonary hemodynamics and the influence of the contrast doses on left ventricular opacification. Bac kground. New intravenous transpulmonary echo contrast agents are promi sing, allowing contrast stress echocardiography and myocardial contras t echocardiography. Nevertheless, some shortcomings still remain. Thus , the pulmonary hypertension observed in pigs after Albunex injection should be investigated in humans, and the optimal dose of contrast age nt remains to be determined because previous experiments indicated tha t the left ventricular opacification and attenuation are dose dependen t. Methods. Albunex in doses of 0.08 and 0.22 ml/kg was successively i njected intravenously in 20 catheterized patients; in 11 of them, anti -inflammatory drugs were withdrawn to avoid the blocking of an eventua l thromboxane-mediated pulmonary artery hypertension. Systemic blood p ressure and pulmonary artery, capillary wedge and right atrial pressur es were continuously monitored. Cardiac output, left ventricular fract ional shortening and blood gases were determined 5 min before and 5 an d 10 min after each injection. The left ventricular opacification was qualitatively assessed by three independent observers using a grading scale from 0 to 3, with 0 indicating an absence of contrast effect and 3 indicating full opacification. Results. No clinical, hemodynamic or respiratory adverse reactions were observed in any patient. Irrespect ive of doses, a left ventricular opacification grade greater-than-or-e qual-to 2 was observed in 74% of the 35 injections that could be evalu ated. This percentage increased to 94% when the higher dose group was considered alone. Conclusions. This first report of the effect of Albu nex injected intravenously on pulmonary artery pressures in humans dem onstrates that this contrast agent appears to be safe. The significant left ventricular opacification obtained in a majority of patients wit hout an important increase in attenuation supports the use of the high er dose of the contrast agent.