0054: Validation of stress thallium-201/rest technetium-99m sequential dual isotope high-speed myocardial perfusion imaging against fractional flow reserve for the detection of the extent of ischemia.

Objectives The aim of this study was to determine the diagnostic accuracy of stress thallium-201/rest technetium-99m sequential dual-isotope high-speed myocardial perfusion imaging (DI-HS-MPI) against invasively determined fractional flow reserve (FFR) and to establish the correlation between myocardium at risk defined by using the invasive BARI-score and DI-HS-MPI. Background Relatively few studies have compared the diagnostic performance of new Cadmium Zinc Telluride - cameras versus FFR. Methods Fifty-four patients referred for angiography underwent DI-HSMPI. Perfusion was scored visually by summed stress score (SSS) on a patient and coronary territory basis, and ischemic burden was calculated by quantitative segmentation of the extent of ischemia. Significant coronary artery disease (CAD) was defined by the presence of ≥90% stenosis/occlusion or fractional flow reserve ≤0.80 in vessels >2mm. The relation between FFR and perfusion was determined for each vascular zone. The BARI-score was calculated from the coronary angiograms to quantify the myocardium at risk. Results FFR was measured in 70 of 162 coronary vessels; Vessels FFR measured per patient was 1.3±0.57. Sensitivity, specificity, and diagnostic accuracy of MPI for the detection of significant CAD were 92%, 88%, and 90% by coronary territory and 87%, 93%, and 92%, on a patient basis. The area under the summary receiver-operating characteristic at the patient level was 0.94 (95% CI: 0.88 to 1) and 0.90 (95% CI: 0.83 to 0.97) at the artery and territory levels, respectively. The mean ischemic burden for MPI and BARI-score showed a strong correlation between techniques (r=0.71, P<0.0001). Conclusions Stress thallium-201/rest technetium-99m sequential DI-HSMPI accurately detects functionally significant CAD as defined by using FFR and provides an assessment of ischemic burden in agreement with the invasive BARI-score. [ABSTRACT FROM AUTHOR]