DOBUTAMINE ECHOCARDIOGRAPHY AND QUANTITATIVE REST-REDISTRIBUTION TL-201 TOMOGRAPHY IN MYOCARDIAL HIBERNATION - RELATION OF CONTRACTILE RESERVE TO 201TL UPTAKE AND COMPARATIVE PREDICTION OF RECOVERY OF FUNCTION

Background The purposes of this study were to evaluate the comparative accuracy of dobutamine echocardiography and quantitative rest-redistr ibution Tl-201 tomography in the prediction of recovery of function af ter revascularization and to assess the relation of contractile reserv e to thallium uptake. Methods and Results Thirty-four patients with st able coronary disease and regional dysfunction underwent dobutamine ec hocardiography (2.5 up to 40 mu g . kg(-1) . min(-1)) and rest-redistr ibution Tl-201 tomography 1 day before revascularization. Resting echo cardiography and scintigraphy were repeated at greater than or equal t o 6 weeks. Before revascularization, resting Tl-201 uptake was similar in segments demonstrating biphasic or sustained improvement and was h igher than in those exhibiting no change or worsening function during dobutamine. After revascularization, Tl-201 uptake increased only in s egments that showed a biphasic response (from 66+/-12% to 78+/-13%; P< .05). Biphasic response had a sensitivity of 74% and specificity of 89 % for prediction of recovery. The use of biphasic or sustained improve ment responses increased the sensitivity to 86% with a decrease in spe cificity to 68%. Qualitative thallium assessment provided a high sensi tivity (98%) but poor specificity (27%). Quantification of thallium up take, however, improved its accuracy: a maximal uptake (at rest or red istribution) of greater than or equal to 60% yielded a 90% sensitivity and a 56% specificity. Conclusions In patients with myocardial hibern ation, biphasic response during dobutamine is less sensitive but more specific for recovery of function, whereas indexes of Tl-201 scintigra phy are in general more sensitive and less specific, the least accurat e being a qualitative assessment of thallium uptake. The sensitivity a nd specificity of both methods, however, can be altered depending on t he quantitative criteria of thallium uptake or combination of response s of the myocardium to dobutamine.