Improved diagnostic accuracy of planar imaging with technetium 99m-labeled tetrofosmin compared with thallium-201 for the detection of coronary artery disease

Background. Receiver operating characteristic (ROC) curve analysis provides detailed information about the performance of a diagnostic test. Methods and Results. As part of a multicenter phase III trial, 160 patients with known or suspected coronary artery disease underwent planar stress-rest ^99mTc-labeled tetrofosmin and stress-redistribution ²⁰¹Tl imaging within 14 days of each other, to compare the diagnostic accuracy of these imaging modalities by ROC curve analysis. Coronary arteriography was used as the reference standard and greater than 70% stenosis was considered significant. ROC curve analysis showed improved detection of coronary artery disease with ^99mTc-labeled tetrofosmin compared with ²⁰¹Tl, with ROC curve areas of 0.765 versus 0.644, respectively (p = 0.02), ^99mTc-labeled tetrofosmin also better identified single-vessel disease in those without previous myocardial infarction (ROC curve areas of 0.684 vs 0.510 for ^99mTc-labeled tetrofosmin and ²⁰¹Tl, respectively; p = 0.04) and enhanced the detection of multivessel disease in those with previous myocardial infarction (ROC curve areas of 0.764 vs 0.638, respectively; p = 0.02). Conclusions. Detailed assessment of diagnostic performance by ROC curve analysis shows that, for planar imaging, ^99mTc-labeled tetrofosmin enhances the detection of coronary artery disease compared with ²⁰¹Tl.