INFLUENCE OF THE ASSESSMENT OF DEFECT SEVERITY AND INTRAVENOUS NITRATE ADMINISTRATION DURING TRACER INJECTION ON THE DETECTION OF VIABLE HIBERNATING MYOCARDIUM WITH DATA-BASED QUANTITATIVE TECHNETIUM 99M-LABELED SESTAMIBI SINGLE-PHOTON EMISSION COMPUTED-TOMOGRAPHY

Background. This study aimed to verify whether the assessment of defec t severity and the infusion of nitrates during tracer injection improv e the capability of data-based Tc-99m-labeled sestamibi single-photon emission computed tomography (SPECT) to recognize hibernating myocardi um. Methods and Results. Of 66 asynergic coronary territories in 40 pa tients with left ventricular dysfunction, 28 had postrevascularization functional recovery (hibernating) and 38 had unchanged dysfunction (f ibrotic), Defect severity was lower in the hibernating than in the fib rotic territories on both baseline (p < 0.01) and nitrate SPECT (p < 0 .002), Nitrate was superior to baseline SPECT to differentiate the hib ernating from the fibrotic territories (sensitivity 96% vs 75%, p < 0. 05; receiver-operating characteristic curve area 0.75 vs 0.63, p < 0.0 01) and to identify the patients with improved left ventricular ejecti on fraction (receiver-operating characteristic curve area 0.68 vs 0.58 ; p < 0.05). Conclusions. The analysis of defect severity in combinati on with nitrate infusion clearly improves the value of Tc-99m-labeled sestamibi SPECT for the recognition of hibernating myocardium and the prediction of postrevascularization recovery.