Forty-two patients (28 men and 14 women) with acute
myocardial infarction (35 Q, seven non-Q wave) were injected with 2.0 mCi
indium 111-labeled antimyosin (AM)
monoclonal antibody (111In AM) within 48 hours of the onset of
chest pain. Forty-eight hours later (72-96 hours after onset of
chest pain), patients were injected with 2.2 mCi
thallium 201, and two sets of single-photon emission computed tomography (SPECT) images were obtained simultaneously using dual energy windows set for the 247 keV
indium photopeak and the 70 keV
thallium peak. Seventeen patients had repeat scans at 4 hours. 111In AM uptake and 201Tl defects were localized to one or more of 24 coronal and sagittal segments. Scans with only 201Tl defects and corresponding 111In AM uptake were classified as matches; scans with unmatched 201Tl defects in addition to matching regions corresponding to electrocardiographic
infarct location were classified as mismatches; and scans with 201Tl and 111In AM uptake in the same segments were classified as overlap. Scan patterns were correlated with clinical evidence for residual
ischemia occurring within 6 weeks of
infarct and including
infarct extension, recurrent angina, and positive predischarge low-level or 6-week symptom-limited stress tests and with coronary anatomy. Fourteen patients had only matching patterns (group 1), 23 had mismatches (group 2), and five had 201Tl-111In overlap as the predominant pattern. None of the patients in group 1 had previous
myocardial infarction; in each, the matched area corresponded to the Q wave location on electrocardiogram, and none had further in-hospital ischemic events or positive stress tests.(ABSTRACT TRUNCATED AT 250 WORDS)