Effect of TRK-100, a stable orally active prostacyclin analogue, on platelet function and plaque size in atherothrombotic strokes.
Patients with carotid atheromatous lesions were prospectively studied with indium-111 platelet imaging, platelet aggregability and B-mode real-time ultrasound tests to determine the short-term effects of orally active prostacyclin analogue TRK-100 (40 micrograms, three times daily for 4 weeks). To establish baseline values, all patients underwent indium-111 platelet imaging, platelet aggregation study and B-mode ultrasound. The results were positive for carotid plaque and platelet accumulation. Visual analysis showed repeated platelet scintigrams to be unchanged in five patients without antithrombotic therapy; repeated ultrasound studies showed no change in eight of ten plaques, while one showed progression and one regression of the plaque. In five TRK-100 treated patients, five of seven lesions with platelet accumulation at the baseline became negative, and two remained unchanged during the treatment; repeated B-mode ultrasound tests indicated eight of nine plaques remained unchanged, while one showed plaque size reduction. Quantitative analysis demonstrated that, TRK-100 significantly reduced the ADP aggregation (1 microM) from 55.2 +/- 21.3% to 24.0 +/- 14.7% (+/- SD; p less than 0.05) and the platelet accumulation index (25.7 +/- 17.2% vs 10.4 +/- 10.4%; p less than 0.05). However, there was no significant reduction in plaque scores during TRK-100 therapy compared with the baseline (2.70 +/- 2.75 mm vs 2.51 +/- 2.58 mm). The data obtained suggested that short-term TRK-100 therapy has an inhibitory effect on platelet accumulation in carotid atheroma but does not cause significant changes in plaque size.
Isaka
Y
Y
Department of Cardiovascular Medicine, Osaka National Hospital, Japan.
Handa
N
N
Imaizumi
M
M
Kimura
K
K
Kamada
T
T
D000284:Administration, Oral; D000368:Aged; D001161:Arteriosclerosis / Q000097:blood / Q000188:drug therapy* / Q000473:pathology; D001792:Blood Platelets / Q000187:drug effects / Q000473:pathology / Q000502:physiology; D002340:Carotid Artery Diseases / Q000097:blood / Q000188:drug therapy* / Q000473:pathology; D011464:Epoprostenol / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000627:therapeutic use; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage / Q000627:therapeutic use; D013927:Thrombosis / Q000097:blood / Q000188:drug therapy / Q000473:pathology
D010975:Platelet Aggregation Inhibitors; C048081:beraprost; D011464:Epoprostenol