[Relationship between static images of 13N ammonia positron emission tomography and left ventricular wall motion in patients with coronary artery disease].

Observed myocardial activities in static image of 13N ammonia positron emission tomography (PET) contains factors about not only myocardial blood flow but also wall motion, wall thickness and glutamine synthetase activity. Those factors may help to delineate myocardial viability in 13N ammonia static image. To assess the role of 13N ammonia static image in prediction of reversibility of regional wall motion abnormalities after revascularization, we studied 20 patients with coronary artery disease. Of these patients, 15 patients underwent successful coronary revascularization (8 PTCA, 7 CABG). Regional 13N concentration before revascularization was expressed as a percent of maximal myocardial concentration and compared with regional wall motion. Wall motion was assessed by visual analysis using left ventriculography. Regional myocardial 13N concentration in normal, hypokinetic, akinetic and dyskinetic segments was 85 +/- 9.3%, 75 +/- 11%, 71 +/- 17% and 58 +/- 7.7%*#+, respectively (*p < 0.05 vs. normal, #p < 0.05 vs. hypokinesis, +p < 0.05 vs. akinesis). The segments with functional improvement showed significantly higher concentration of 13N than those without functional recovery (80 +/- 9.7% vs. 67 +/- 8.3%, p < 0.05). By using an optimized threshold value for normalized 13N activities, the sensitivity and specificity reached to 67% and 100%, respectively, to predict functional recovery. Our data suggested that myocardial 13N concentration in static PET image is closely related to the left ventricular wall motion in the patients with coronary artery disease and that it has a possible value of prediction of myocardial viability.