QUANTITATIVE TL-201 EXERCISE SCINTIGRAPHY FOR DETECTION OF CORONARY-ARTERY DISEASE

Abstract

In 140 patients with chest pain quantitation of regional myocardial Tl-201 activity was performed by serial scintigraphic images after treadmill exercise (Ex). Criteria for an abnormal thallium scintigram included the following: .gtoreq. 25% persistent reduction in Tl-201 uptake in anterolateral, anteroseptal, posterolateral and inferoapical segments, or .gtoreq. 35% reduction in the inferior segment; an initial defect with delayed redistribution; and abnormal Tl-201 washout. Of 110 patients with significant coronary artery disease (CAD), 100 had abnormal Tl-201 scintigrams, while 27 of 30 patients with angiographically normal coronary arteries had normal scintigrams; 91% sensitivity, 90% specificity and 97% predictive accuracy. Sensitivity and specificity were not significantly different when the 95 patients with diagnostic (.gtoreq. 85% maximum heart rate [HR]) and 45 with inconclusive (.ltoreq. 85% maximum HR) Ex tests were compared. Comparison of qualitative and quantitative image analyses in a subset of these patients showed that both specificity and multivessel disease prediction were greater when the quantitative approach was used (90 vs. 73% and 78 vs. 39%, respectively). Sensitivity for CAD detection was reduced by 10% with visual interpretation alone. Quantitative exercise Tl-201 scintigraphy appears highly sensitive and specific for CAD detection in patients with chest pain.