Stress technetium-99m tetrofosmin myocardial scintigraphy. A new one-hour protocol for the detection of coronary artery disease

A one-hour protocol for stress myocardial scintigraphy using technetium-99m (99mTc) tetrofosmin was compared with scintigraphy using thallium-201 (201Tl) for the detection of coronary artery disease in 43 consecutive patients who underwent stress 201Tl and 99mTc-tetrofosmin myocardial scintigraphy, and coronary arteriography within 1 week. For the stress 99mTc-tetrofosmin test, rest imaging data were acquired 20 min after intravenous injection of 5-7 mCi 99mTc-tetrofosmin, using a 3-head gamma camera collecting 20-sec views over 360deg. After dobutamine infusion or bicycle ergometer exercise, 20-25 mCi of 99mTc-tetrofosmin was additionally injected at peak stress. The stress images were acquired 15 min after the second injection with 5-sec views over 360deg. All patients also underwent 201Tl exercise and redistribution (4-hour) imaging following a standard protocol. The overall sensitivity for detecting coronary artery disease was 96.0%, with an overall specificity of 93.3% for both types of scintigraphy. Qualitative analyses of 21 conventionally divided left ventricular segments showed that the overall segmental concordance between the 99mTc-tetrofosmin and 201Tl imagings was 85.2% on the rest images and 82.1% on the stress images. The segmental concordance of the rest images was 87.0% in patients with neither significant stenosis nor myocardial infarction, 86.2% in patients with significant stenosis without myocardial infarction, and 82.9% in patients with significant stenosis and myocardial infarction, and the concordance values of the stress images were 85.4%, 87.5% and 75.6%, respectively. These preliminary results suggest that stress myocardial scintigraphy using the present new protocol is a promising approach for the detection of coronary artery disease, with diagnostic sensitivity and specificity comparable to those of stress 201Tl scintigraphy. (author)