Nitrate-enhanced thallium 201 single-photon emission computed tomography imaging in hibernating myocardium

Objectives This study tested the usefulness of nitrate-enhanced thallium 201 imaging for detecting myocardial viability. Background Previous work suggests that nitrates enhance the ability of 201Tl imaging to detect viable myocardium. Methods Eighteen patients with coronary artery disease underwent 201Tl imaging at rest, after 4 hours of redistribution, and during intravenous nitroglycerine infusion (mean dose = 5.96 ± 5.37 μg/kg/min). Twelve patients had their echocardiograms repeated after revascularization. Perfusion and wall motion were scored from 0 to 2 (absent to normal). Results All the regions identified as viable by the rest/redistribution pair of scans were identified as viable by the rest/nitroglycerine pair of scans. Ninety-one percent of these regions were identified as viable by the single nitroglycerine scan alone. In patients who underwent revascularization, the total 201Tl perfusion score improved from 193 to 214 after revascularization (P = .009). Wall motion score improved from 151 to 168 after revascularization (P = .09). Both the rest/nitroglycerine and rest/redistribution studies correctly predicted 14 (88%) of 16 regions that improved after revascularization. Most importantly, the rest/nitroglycerine and rest/redistribution studies were able to predict postrevascularization myocardial viability (absence of akinesis or dyskinesis after revascularization), with a sensitivity of 95% and 92%, respectively, and a predictive accuracy of 84.4%. Conclusions Nitroglycerine infusion during 201Tl imaging is a useful technique for detecting underperfused, viable myocardium, requires less time to perform than rest/redistribution imaging, and may allow detection of viable myocardium with a single 201Tl single-photon emission computed tomographic study. (Am Heart J 1999;138:369-75.)