COMBINED EVALUATION OF REST-REDISTRIBUTION TL-201 TOMOGRAPHY AND LOW-DOSE DOBUTAMINE ECHOCARDIOGRAPHY ENHANCES THE IDENTIFICATION OF VIABLEMYOCARDIUM IN PATIENTS WITH CHRONIC CORONARY-ARTERY DISEASE

The purpose of this study was to evaluate whether combined evaluation by discriminant analysis of rest-redistribution thallium-201 tomograph y and low-dose dobutamine echocardiography enhances the accuracy iu id entifying viable myocardium in patients with chronic corollary artery disease. Rest-redistribution Tl-201 has high sensitivity but low speci ficity in identifying via ble myocardium, while the opposite is true f or lour-dose dobutamine echocardiography. Forty-six patients underwent low-dose dobutamine echocardiography and rest-redistribution Tl-201 t omography on the same day. Rest echocardiography was repealed at least 30 days (mean 40+/-20) after myocardial revascularization. Discrimina nt analysis was applied to the results of Tl-201 tomography and dobuta mine echocardiography to classify a/dyskinetic segments as viable or n on-viable, In 92 a/dyskinetic segments that were revascularized, rest- redistribution Tl-201 tomography yielded an accuracy of 75%, while the accuracy of dobutamine echocardiography was 70% (P<0.05). When discri minant analysis was used, the combined evaluation gave an accuracy of 83% (P<0.05 vs both tests). These findings demonstrate that low-dose d obutamine echocardiography and Tl-201 imaging are useful and complemen tary techniques for identifying viable myocardium in patients with chr onic coronary artery disease. Combined evaluation by discriminant anal ysis significantly improves accuracy, although the cost effectiveness of such an approach remains to be determined.