Prediction of 6-year prognosis for cardiac event by thallium-201 single-photon emission computed tomography (SPECT) with treadmill exercise test

To examine thallium-201 single-photon emission computed tomography (SPECT) with a treadmill exercise test can predict the long-term prognosis of patients with coronary artery disease, 95 patients (71 men, 24 women) who underwent a treadmill exercise test with thallium-201 SPECT from April to December 1986 were followed for 6 years. Three short-axis slices at the apical, mid- and basal-level were selected, and each slice was divided into eight segments. Each segment count was assigned a score according to the count range in the slice (score 0, count range 76-100%; 1, 51-75%; 2, 26-50%; 3, 1-25%; 4, 0%) by evaluating the mean value of the slice. The total T1 defect score of each segment in 3 slices was summed (sigma T1 defect score). The 'early sigma T1 defect score' was the sigma T1 defect score 5 min after treadmill exercise, and the 'late sigma T1 defect score' was sigma T1 defect score measured 4 h after treadmill exercise. Cardiac events occurred in 27 of the 95 patients: cardiac death 3; myocardial infarction 1; percutaneous transluminal angioplasty 16; coronary artery bypass graft 5; congestive heart failure 3. Univariate analysis showed that previous myocardial infarction (p < 0.01), exercise work load (p < 0.05), early sigma T1 defect score (p < 0.01) and late sigma T1 defect score (p < 0.01) were independent predictors of the prognosis. These results suggest that thallium-201 SPECT with the treadmill exercise test could be applicable and useful to predict long term prognosis.