Re-innervation after heart transplantation: a multidisciplinary study.
BACKGROUND
Several authors have demonstrated the existence and implications of re-innervation in the transplanted heart. Our aim was to study this phenomenon using 3 different techniques and to analyze the correlation among them.


METHODS
The study population consisted of 55 patients who had undergone heart transplantation 0.5 to 160 months earlier. We used a control group of 10 healthy individuals for comparison. To detect re-innervation, we used 1) planar and single photon emission computed tomography (SPECT) scintigraphic imaging of cardiac sympathetic activity with 123I-metaiodobenzylguanidine (MIBG), 2) analysis of heart-rate variability based on 24-hour Holter recordings; and 3) immunohistochemical study of endomyocardial biopsy specimens with anti-S100 antibody.


RESULTS
The SPECT images showed evidence of sympathetic re-innervation in 17 patients (31%), predominantly in the anterior and in the septal regions of the left ventricle. Sympathetic activity increased during the post-transplant time course (r = 0.32; p = 0.017), although it did not reach normal values. We found a correlation between the low-frequency component of heart-rate variability (a marker of sympathetic activity) and the degree of MIBG uptake according to scintigraphy (r = 0.32; p = 0.015). Immunostaining study demonstrated the existence of nerve fibers in 36 patients (65%) who had greater values of heart-rate variability parameters reflecting parasympathetic activity.


CONCLUSIONS
The 3 techniques evidenced re-innervation after heart transplantation. A correlation exists between sympathetic activity detected using MIBG scintigraphy and analysis of heart-rate variability. Patients in whom endomyocardial biopsy specimen reveals the presence of nerve fibers show more parasympathetic activity in the heart-rate variability analysis.
Gallego-Page
Juan Carlos
JC
Servicio de Cardiología, Complejo Hospitalario, Albacete, Spain. jsecu@eresmas.net
Segovia
Javier
J
Alonso-Pulpón
Luis
L
Alonso-Rodríguez
Mercedes
M
Salas
Clara
C
Ortíz-Berrocal
José
J
D019797:3-Iodobenzylguanidine; D000293:Adolescent; D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging / Q000294:innervation* / Q000503:physiopathology; D006339:Heart Rate / Q000502:physiology; D016027:Heart Transplantation; D006801:Humans; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology; D009416:Nerve Regeneration; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D019737:Transplants
D019275:Radiopharmaceuticals; D019797:3-Iodobenzylguanidine