[SH/TA-508 clinical phase II study: dose evaluation of SH/TA-508 in echocardiography]

A cooperative study was conducted at 18 institutions to evaluate the safety and usefulness of SH/TA-508, a contrast medium for ultrasound diagnosis, and to find its optimum dose. One hundred and one patients with confirmed or suspected ischemic heart disease were examined with two-dimensional echocardiography, and 95 patients with mild mitral insufficiency were studied with the color Doppler method. The contrast medium was administered at low-dose (1.5-1.6g galactose) and high-dose (3.0-3.2 g galactose) levels at concentrations of 200, 300 and 400 mg/ml. The contrast effect was evaluated into five grades by two-dimensional echocardiography: - (ineffective), + (weak), 2+ (moderate), 3+ (good), 4+ (excessive effect) and into four grades with the color Doppler method, - (ineffective), + (weak), 2+ (optimum), 3+ (excessive effect). The two-dimensional echocardiographic studies showed effects graded at 2+ and above in most patients (83-93%). These findings were significantly more common in patients who had received the 300 and 400 mg/ml concentrations than in those who received the 200 mg/ml concentration. Statistical analysis found no significant differences between the high-dose and low-dose groups. Color Doppler echocardiography found signal enhancement graded at 2+ and above in 80-93% of cases. There were no significant differences in enhancement effect attributable to concentration or total dose. However, since excessive signal intensity was seen quite frequently, the dose levels in the present study were considered to be a little too high. Side effects includes transient feelings of warmth or cold, and the incidence of side effects was higher at higher doses and concentrations. The results show that the optimum concentration for two-dimensional echocardiography is 300 mg/ml and for color Doppler 200 mg/ml. No particular safety problems were seen with SH/TA-508, and this contrast medium is useful in echocardiography of the left ventricle and in enhancing mitral regurgitation signals in color Doppler examinations. Therefore, a phase III multicenter trial should be performed.