Cardiac neuroceptor imaging on acute myocardial ischemia model using 11C-methyldopamine

Objective To evaluate 11C-MDA, a cardiac sympathetic nerve presynaptic molecular probe, in acute myocardial ischemia (AMI) and to compare with 13N-Ammonia myocardial perfusion imaging. Methods Twelve Bama miniature pigs were used to establish AMI models. 11C-MDA and 13N-Ammonia PET/CT were performed before and after model establishment. The defect fraction, ratio of defect to normal region, defect volume of 11C-MDA and 13N-Ammonia PET/CT were calculated. Paired-t test and two-sample t test were used. Results Eight models were established successfully and 4 pigs died. The defect fractions on 11C-MDA and 13N-Ammonia myocardial imaging were significantly different (13.4±3.3 vs 7.4±1.0, 18.8±4.4 vs 4.8±1.0, 10.5±4.2 vs 4.4±0.9; t values: 4.901, 8.864, 4.030, all P<0.001) at the first, third and sixth month post-model establishment. The ratios of defect to normal region on 11C-MDA and 13N-Ammonia PET/CT myocardial images were significantly different (0.47±0.14 vs 0.59±0.10, 0.43±0.13 vs 0.61±0.09; t values: -2.166, -3.415, both P<0.05) at the first and third month post-model establishment. The defect volumes on 11C-MDA and 13N-Ammonia PET/CT were significantly different ((4.20±0.34) vs (2.55±0.11) cm3, (10.66±0.71) vs (2.46±0.12) cm3, (5.95±0.50) vs (2.44±0.11) cm3;t values: 12.925, 32.149, 19.440, all P<0.001) at the first, third and sixth month post-model establishment. Conclusions Myocardial ischemia-reperfusion and cardiac sympathetic restoration might occur at different times. The recovery of myocardial ischemia-reperfusion is earlier than that of the cardiac sympathetic nerve. Key words: Myocardial ischemia; Sympathetic nervous system; Positron-emission tomography; Tomography, X-ray computed; Deoxyepinephrine; Ammonia; Swine