Rest—redistribution thallium-201 scintigraphy to determine myocardial viability early after myocardial infarction

Objectives. This study attempted to determine the utility of early rest—redistribution thallium-201 imaging in detecting residual myocardial viability after myocardial infarction. Background. The early detection of myocardial viability after myocardial infarction would have clinical relevance. Methods. Thirty-one patients with acute myocardial infarction had early (mean [±SD] 2 ± 1 day) rest—redistribution thallium-201 imaging followed by radionuclide and coronary angiography. Late studies included stress—redistribution—reinjection thallium-201 imaging or radionuclide angiography, or both. Viability was defined by the rest thallium-201 scan as an initial mild rest defect or any defect that demonstrated redistribution. Results. Group 1 (n = 15) was predicted to have viable and Group 2 (n = 16) nonviable myocardium in the infarct zone. Group 1 patients were more likely to have patent infarct-related artery (15 of 15 vs. 10 of 16, p < 0.03), higher initial ejection fraction (61 ± 12% vs. 53 ± 9%, p < 0.05), higher infarct wall motion score (p < 0.0001) and fewer abnormal thallium-201 segments (p < 0.0001). On follow-up studies, ejection fraction improved in Group 1 (from 57 ± 13% to 66 ± 10%, p < 0.05, N = 9) and deteriorated in Group 2 (from 53 ± 10% to 46 ± 8%, p < 0.05, N = 13). On late stress testing with thallium-201 reinjection, Group 1 patients had fewer abnormal segments (p < 0.03) and higher infarct zone counts during exercise (p < 0.05) and after reinjection (p < 0.05) than Group 2 patients. Conclusions. If confirmed by larger studies, early rest—redistribution thallium-201 imaging may be useful technique for identifying residual viability after myocardial infarction.