Cardiac sympathetic denervation assessed with 123-iodine metaiodobenzylguanidine imaging predicts ventricular arrhythmias in implantable cardioverter-defibrillator patients.
OBJECTIVE
The purpose of this study was to evaluate whether 123-iodine metaiodobenzylguanidine (123-I MIBG) imaging predicts ventricular arrhythmias causing appropriate implantable cardioverter-defibrillator (ICD) therapy (primary end point) and the composite of appropriate ICD therapy or cardiac death (secondary end point).


BACKGROUND
Although cardiac sympathetic denervation is associated with ventricular arrhythmias, limited data are available on the predictive value of sympathetic nerve imaging with 123-I MIBG on the occurrence of arrhythmias.


METHODS
Before ICD implantation, patients underwent 123-I MIBG and myocardial perfusion imaging. Early and late 123-I MIBG (planar and single-photon emission computed tomography [SPECT]) imaging was performed to assess cardiac innervation (heart-to-mediastinum ratio, cardiac washout rate, and 123-I MIBG SPECT defect score). Stress-rest myocardial perfusion imaging was performed to assess myocardial infarction and perfusion abnormalities (perfusion defect scores). During follow-up, appropriate ICD therapy and cardiac death were documented.


RESULTS
One-hundred sixteen heart failure patients referred for ICD therapy were enrolled. During a mean follow-up of 23 +/- 15 months, appropriate ICD therapy (primary end point) was documented in 24 (21%) patients and appropriate ICD therapy or cardiac death (secondary end point) in 32 (28%) patients. Late 123-I MIBG SPECT defect score was an independent predictor for both end points. Patients with a large late 123-I MIBG SPECT defect (summed score >26) showed significantly more appropriate ICD therapy (52% vs. 5%, p < 0.01) and appropriate ICD therapy or cardiac death (57% vs. 10%, p < 0.01) than patients with a small defect (summed score </=26) at 3-year follow-up.


CONCLUSIONS
Cardiac sympathetic denervation predicts ventricular arrhythmias causing appropriate ICD therapy as well as the composite of appropriate ICD therapy or cardiac death.
Department of Cardiology, Leiden University Medical Center, Leiden, the Netherlands.
Mark J
MJ
Boogers
C Jan Willem
CJ
Borleffs
Maureen M
MM
Henneman
Rutger J
RJ
van Bommel
Jan
J
van Ramshorst
Eric
E
Boersma
Petra
P
Dibbets-Schneider
Marcel P
MP
Stokkel
Ernst E
EE
van der Wall
Martin J
MJ
Schalij
Jeroen J
JJ
Bax
D019797:3-Iodobenzylguanidine; D000368:Aged; D055426:Cardiac-Gated Single-Photon Emission Computer-Assisted Tomography / Q000379:methods*; D016757:Death, Sudden, Cardiac / Q000209:etiology / Q000517:prevention & control; D017147:Defibrillators, Implantable; D003937:Diagnosis, Differential; D005260:Female; D005500:Follow-Up Studies; D006321:Heart / Q000000981:diagnostic imaging / Q000294:innervation*; D006801:Humans; D008297:Male; D011237:Predictive Value of Tests; D011379:Prognosis; D019275:Radiopharmaceuticals; D013562:Sympathectomy / Q000379:methods*; D013564:Sympathetic Nervous System / Q000000981:diagnostic imaging / Q000601:surgery*; D017180:Tachycardia, Ventricular / Q000000981:diagnostic imaging / Q000628:therapy*
D019275:Radiopharmaceuticals; D019797:3-Iodobenzylguanidine