Comparison of baseline and low-dose dobutamine technetium-99m sestamibi scintigraphy with low-dose dobutamine echocardiography for predicting functional recovery after revascularization

Injection of sestamibi during low-dose dobutamine (LDD) infusion might impr ove tracer ability to detect viable myocardium. This study investigated the potential value of LDD technetium-99m sestamibi (sestamibi) single-photon emission computed tomography (SPECT) in predicting functional recovery afte r revascularization by comparing its results with those of sestamibi SPECT at rest and of LDD echocardiography. Before revascularization, 23 patients with chronic coronary artery disease and regional left ventricular dysfunct ion underwent sestamibi SPECT at rest and, on a separate day, LDD echocardi ography and sestamibi SPECT with tracer injection during LDD infusion. Echo cardiography at rest was repeated after revascularization. Semiquantitative sestamibi uptake results (grading from 0 = normal to 4 = absent) and wall motion (grading from 1 = normal to 4 = dyskinesia) were evaluated with a 16 -segment model. The ventricular wall was divided into 3 vascular territorie s. At follow-up, 20 of 32 asynergic vascular territories showed functional recovery, whereas 12 showed no changes. For prediction of functional recove ry, LDD SPECT achieved better accuracy than SPECT at rest (87% vs 65%, p <0 .05); positive and negative predictive values of LDD SPECT were 90% and 83% , respectively, which was not significantly different from the related LDD echocardiographic values (84% and 69%). Thus, LDD sestamibi SPECT appears t o be a promising method for detecting myocardial viability, which provides better accuracy than sestamibi SPECT at rest, and achieves predictive value s comparable to those of LDD echocardiography. (C)2000 by Excerpta Medica, Inc.