Myocardial tomography using technetium-99m-tetrofosmin to evaluate coronary artery disease

To assess the clinical value of the 99mTc-labeled myocardial perfusion agent, 99mTc-tetrofosmin, the findings of stress and rest myocardial tomography were compared with those of stress and 3-hr delayed 201Tl tomography and coronary arteriography.

Twenty-five patients who had coronary arteriography were studied with both stress tetrofosmin and 201Tl tomography.

The image quality of tetrofosmin was superior to that of 201Tl despite a shorter acquisition time. Both the tetrofosmin and 201Tl studies were quite sensitive to detect coronary artery disease (100% and 95%, respectively) (p = ns). The two studies showed similar sensitivity (75% and 73%) and specificity (80% and 77%, respectively) for the detection of significant (> or = 75% diameter) coronary artery stenosis. Stress distribution of tetrofosmin tended to be slightly higher than that of 201Tl (% uptake: 63.3% +/- 13.5% versus 60.4% +/- 12.2%, p = 0.0006; uptake score: 2.33 +/- 1.03 versus 2.22 +/- 1.07, p = 0.007), indicating less defect contrast in the former. A high concordant rate (89%) of the stress perfusion score was observed between the two radiopharmaceuticals. Reversible perfusion abnormalities were observed to be similar between stress-rest tetrofosmin and stress-delayed 201Tl studies.

Stress tetrofosmin perfusion tomography is a valuable method to detect coronary artery disease and to assess tissue viability with accuracy similar to that of stress 201Tl tomography.