NONINVASIVE DIAGNOSIS OF CORONARY-ARTERY STENOSIS IN WOMEN WITH LIMITED EXERCISE CAPACITY - COMPARISON OF DOBUTAMINE STRESS ECHOCARDIOGRAPHY AND TC-99M SESTAMIBI SINGLE-PHOTON EMISSION CT

Objectives: To compare the accuracy of dobutamine stress echocardiogra phy (DSE) and simultaneous Tc-99m sestamibi (MIBI) single-photon emiss ion CT (SPECT) imaging for the diagnosis of coronary artery stenosis i n women. Patients: Seventy women with limited exercise capacity referr ed for evaluation of myocardial ischemia, Methods: DSE (up to 40 mu g/ kg/min) was performed in conjunction with stress MIBI SPECT. Resting M IBI images were acquired 24 h after the stress test. Ischemia was defi ned as new or worsened wall motion abnormalities confirmed by DSE and as reversible perfusion defects confirmed by MIBI, Significant coronar y artery disease was defined as greater than or equal to 50% luminal d iameter stenosis. Results: DSE was positive for ischemia in 35 of 45 p atients with coronary artery stenosis and in 2 of 25 patients without coronary artery stenosis (sensitivity = 78% CI, 68 to 88; specificity = 92% CI, 85 to 99; and accuracy = 83% CI, 74 to 92), A positive MIBI study for ischemia occurred in 29 patients with coronary artery stenos is and in 7 patients without coronary artery stenosis (sensitivity = 6 4% CI, 53 to 76; specificity = 72% CI, 61 to 83; and accuracy = 67% CI , 56 to 78 [p < 0.05 vs DSE]). In the 59 vascular regions with coronar y artery stenosis, the regional sensitivity of DSE was higher than MIB I (69% CI, 62 to 77 vs 51% CI, 42 to 59, p < 0.05), whereas specificit y in the 81 vascular regions without significant stenosis was similar (89% CI, 84 to 94 vs 88% CI, 82 to 93, respectively). Conclusion: DSE is a useful noninvasive method for the diagnosis of coronary artery st enosis in women and provides a higher overall and regional diagnostic accuracy than dobutamine MIBI SPECT in this particular population.