ABSTRACT
To evaluate viability and severity of ischemically damaged myocardium, myocardial single emission tomography (SPECT) using 123I-BMIPP (BMIPP), a new tracer of myocardial metabolism of fatty acid, was performed before and after coronary artery bypass grafting (CABG). 201Tl myocardial SPECT (Tl) and left ventriculography (LVG) were also used. Thirty-three revascularized areas in eight patients were investigated. (1) Areas showing good redistribution on Tl and normal uptake on BMIPP indicated good viability and simple ischemic myocardium. Postoperative uptake of both tracers returned to normal levels. (2) Areas showing good redistribution on Tl and severely decreased uptake on BMIPP indicated jeopardized myocardium with severe ischemia. All such areas were seen in patients with unstable angina. Postoperative uptake of both tracers returned to normal levels. (3) Areas showing poor redistributionor severely decreased uptake on Tl and slight uptake on BMIPP indicating hibernating areas. Postoperative uptake became normal or better than preoperative uptake on Tl necrosis. However on BMIPP, the uptake was unchanged or recovered slightly. (4) Areas showing complete defect in Tl and BMIPP indicated necrosis and had no viability. Postoperatively the defect in both tracers were unchanged. Therefore, these areas required no revascularization. The ischemic state of myocardium could be assessed by evaluation of uptake patterns of BMIPP and Tl using myocardial SPECT. Therefore, using this new tracer of myocardial fatty acid metabolism “BMIPP”is useful for deciding culprit and viable lesions requiring coronary revascularization and evaluating therapeutical effects.