Accurate assessment of myocardial viability permits selection of patients who would benefit from myocardial revascularization. Currently, rest-redistribution thallium-201 scintigraphy and low-dose dobutamine echocardiography are among the most used techniques for the identification of viable myocardium. Thirty-one consecutive patients (all men, mean age 60±8 years) with chronic coronary artery disease and reduced left ventricular ejection fraction (31%±7%) were studied. Rest 201Tl single-photon emission tomography (SPET), low-dose dobutamine echocardiography and radionuclide angiography were performed before revascularization. Radionuclide angiography and echocardiography were repeated after revascularization. An a/dyskinetic segment was considered viable on 201Tl SPET when tracer uptake was >65%, while improvement on low-dose dobutamine echocardiography was considered a marker of viability. Increase in global ejection fraction was considered significant at ≥5%. In identifying viable segments, rest 201Tl SPET showed higher sensitivity than low-dose dobutamine echocardiography (72% vs 53%, P201Tl SPET in group 1 than in group 2 (2.6±1.9 vs 0.6±1.2, P201Tl SPET and post-revascularization changes in ejection fraction (r=0.52, P201Tl SPET had a higher sensitivity (82% vs 53%, P=0.07) and showed a trend towards higher accuracy and specificity (77% vs 58%, and 71% vs 64%, respectively) as compared with low-dose dobutamine echocardiography. In conclusion, these findings suggest that when severely reduced global function is present, rest 201Tl SPET evaluation of viability is more accurate than low-dose dobutamine echocardiography for the identification of patients who will benefit most from revascularization.
- Dobutamine echocardiography
- Myocardial revascularization
- Viable myocardium
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging