title: Reappearance of cardiac presynaptic sympathetic nerve terminals in the transplanted heart: correlation between PET using (11)C-hydroxyephedrine and invasively measured norepinephrine release.
abstract: 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 (11)C-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 >7%/min were defined as reinnervated. Additionally, transcardiac NE release induced by intravenous tyramine (55 microg/kg) was measured by coronary sinus and aortic catheterization within 1 wk of the PET study. NE levels between coronary sinus and aortic root, DeltaNE(CS-AO), were calculated at baseline and after tyramine administration. Differences of more than 3 SD of baseline (>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. DeltaNE(CS-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 DeltaNE(CS-AO) measurements (P = 0.002). Maximal HED retention was also significantly correlated with NE release (r = 0.69; P = 0.001).
  
  
  CONCLUSIONS
  Results of invasively measured NE release and noninvasive (11)C-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.
authors: Nuklearmedizinische Klinik der Technischen Universität München, Munich, Germany.
authors: K
authors: K
authors: Odaka
authors: W
authors: W
authors: von Scheidt
authors: S I
authors: SI
authors: Ziegler
authors: P
authors: P
authors: Ueberfuhr
authors: S G
authors: SG
authors: Nekolla
authors: B
authors: B
authors: Reichart
authors: F M
authors: FM
authors: Bengel
authors: M
authors: M
authors: Schwaiger
mesh_terms: D000320:Adrenergic Fibers / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000502:physiology; D000328:Adult; D002250:Carbon Radioisotopes; D004809:Ephedrine / Q000031:analogs & derivatives*; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging / Q000294:innervation*; D016027:Heart Transplantation; D006801:Humans; D008297:Male; D008875:Middle Aged; D009638:Norepinephrine / Q000378:metabolism*; D017729:Presynaptic Terminals / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000502:physiology; D019275:Radiopharmaceuticals; D013566:Sympathomimetics / Q000494:pharmacology; D014055:Tomography, Emission-Computed; D014443:Tyrosine / Q000494:pharmacology
chemical_list: D002250:Carbon Radioisotopes; D019275:Radiopharmaceuticals; D013566:Sympathomimetics; C065363:3-hydroxyephedrine; D014443:Tyrosine; D004809:Ephedrine; D009638:Norepinephrine