PT - JOURNAL ARTICLE AU - Odaka, Kenichi AU - von Scheidt, Wolfgang AU - Ziegler, Sibylle I. AU - Ueberfuhr, Peter AU - Nekolla, Stephan G. AU - Reichart, Bruno AU - Bengel, Frank M. AU - Schwaiger, Markus TI - Reappearance of Cardiac Presynaptic Sympathetic Nerve Terminals in the Transplanted Heart: Correlation Between PET Using <sup>11</sup>C-Hydroxyephedrine and Invasively Measured Norepinephrine Release DP - 2001 Jul 01 TA - Journal of Nuclear Medicine PG - 1011--1016 VI - 42 IP - 7 4099 - http://jnm.snmjournals.org/content/42/7/1011.short 4100 - http://jnm.snmjournals.org/content/42/7/1011.full SO - J Nucl Med2001 Jul 01; 42 AB - Previously, sympathetic reinnervation of the transplanted heart has been described using invasive catheterization techniques and noninvasive radionuclide imaging techniques. However, little is known about the agreement between these 2 methods. Thus, correlation between 11C-hydroxyephedrine (HED) PET and invasively measured norepinephrine (NE) release was investigated in transplant recipients in this study. Methods: Using PET and the catecholamine analog HED, 17 patients were studied between 2 mo and 13.6 y after transplantation. Based on results in completely denervated hearts, areas with HED retention &gt;7%/min were defined as reinnervated. Additionally, transcardiac NE release induced by intravenous tyramine (55 μg/kg) was measured by coronary sinus and aortic catheterization within 1 wk of the PET study. NE levels between coronary sinus and aortic root, ΔNECS–AO, were calculated at baseline and after tyramine administration. Differences of more than 3 SD of baseline (&gt;163 pg/mL) were interpreted as reinnervation. Results: HED retention indicated reinnervation in 10 patients. Maximal HED retention ranged from 4.3%/min to 16.4%/min. ΔNECS–AO 1 min after tyramine administration ranged between −10 pg/mL and 1157 pg/mL, and 8 patients were above the reinnervation threshold. Fisher’s exact test demonstrated good agreement between results of PET and ΔNECS–AO measurements (P = 0.002). Maximal HED retention was also significantly correlated with NE release (r = 0.69; P = 0.001). Conclusion: Results of invasively measured NE release and noninvasive 11C-HED PET are well correlated. This study further supports the usefulness of PET as a noninvasive approach for detection of reappearance of catecholamine uptake sites after heart transplantation.