Imaging experimental coronary artery thrombosis with indium-111 platelets

The ability of cardiac scintigraphy with indium-111 (/sup 111/In)-labeled platelets to detect coronary artery thrombosis (CAT) was assessed in a canine model. Cardiac imaging and tissue distribution studies were performed shortly after administering /sup 111/In-labeled platelets to 12 dogs (group 1) with acute CAT. Four dogs (group 2) with acute CAT were studied 2 and 22 hours after administering /sup 111/In platelets. In addition, four dogs (group 3) with 24-hour-old CAT were similarly evaluated. In all group 1 animals, in vivo imaging 1 to 2 hours after /sup 111/In platelet administration revealed intense uptake in the region of thrombus-containing left anterior descending arteries that was readily discernible from background blood pool activity. Sequential imaging of the four group 2 animals over a 22-hour period revealed no change in the scintigraphic pattern of the thrombosed arteries. In contrast, /sup 111/In platelet imaging in the four group 3 animals with 24-hour-old CAT failed to reveal enhanced activity within the region of the thrombus-containing coronary artery. In the 12 group 1 animals, the CAT accumulated 69 +- 10 (mean +- SEM) times greater activity than present in blood and 651 +- 135 times greater activity than normal left ventricular myocardium. There was 24more » +- 7 times greater /sup 111/In activity in the damaged left anterior descending arteries compared with normal circumflex arteries. Similar uptake ratios were seen in group 2 animals. The 24-hour old thrombi from group 3 animals showed no enhanced /sup 111/In uptake. This study demonstrates that experimental acute CAT can be detected readily with /sup 111/In platelet cardiac scintigraphy.« less