Comparison of rest thallium-201 imaging and rest technetium-99m sestamibi imaging for assessment of myocardial viability in patients with coronary artery disease and severe left ventricular dysfunction

AbstractObjectives. We prospectively compared myocardial uptake of thallium-201 (201Tl) at rest with rest technetium-99m (99mTc) sestamibi uptake in the same patients, using quantitative single-photon emission computed tomography (SPECT).Background. Because of only slightly delayed redistribution, 99mTc-sestamibi uptake at rest may be less than 201Tl uptake, thereby underestimating the extent of viability.Methods. Twenty patients (2.25 stenoses per patient) with a mean left ventricular ejection fraction of 33 ± 2% underwent early and 3-h delayed rest 201Tl SPECT, rest 99mTc-sestamibi SPECT and two-dimensional echocardiography.Results. The 280 scan segments were classified as either a normal, mild reduction in viability, defined as delayed 201Tl uptake ≤75% and ≥5%, or a severe reduction in viability, defined as delayed 201Tl uptake