PREDICTION OF POST-REVASCULARIZATION FUNCTIONAL RECOVERY OF ASYNERGICMYOCARDIUM USING QUANTITATIVE TL-201 REST-REDISTRIBUTION TOMOGRAPHY -HAS THE REVERSE REDISTRIBUTION PATTERN AN INDEPENDENT SIGNIFICANCE

The significance of reverse redistribution on rest-redistribution thal lium-201 myocardial scintigraphy is unclear. Previous studies suggeste d that reverse redistribution segments with normal resting activity in clude viable myocardium? whilst resting defects with further worsening correspond to scar. We evaluated whether reverse redistribution has a n independent significance for the prediction of post-revascularizatio n recovery, particularly as compared with the quantification of redist ribution activity. We studied 26 coronary artery disease patients with left ventricular dysfunction, who underwent Tl-201 rest-redistributio n single-photon emission tomography (SPET) and echocardiography before revascularization, Viability was defined by the detection of wall mot ion improvement on follow-up echocardiography. Tl-201 activity was con sidered normal if greater than or equal to 80%, moderately reduced if <80% but greater than or equal to 50%, and severely decreased if <50%. Reverse redistribution was defined as a defect in redistribution imag es with greater than or equal to 10% decrease in relative Tl-201 activ ity compared with the resting value. Reverse redistribution was detect ed in 33 segments (10%). Baseline dysfunction was equally observed in the reverse re distribution and in the non-reverse redistribution segm ents (64% vs 56%, P=0.40) and the rate of asynergic segments with post -revascularization recovery was not different between the two groups ( 33% vs 54%. P=0.11). The rate of functional recovery in redistribution defects without reverse redistribution was 53% in moderate and 30% in severe defects: the corresponding values for the reverse redistributi on segments were 50% and 27% (all non-significant versus non-reverse r edistribution seg mints), For the prediction of post-revascularization recovery in asynergic segments, the detection of reverse redistributi on on rest-redistribution Tl-201 SPET does not add any information to the quantitative analysis of redistribution activity.