Prognostic value of sympathetic innervation and cardiac asynchrony in dilated cardiomyopathy.
OBJECTIVE
The purpose of the study is to examine prognostic values of cardiac I-123 metaiodobenzylguanidine (MIBG) uptake and cardiac dyssynchrony in patients with dilated cardiomyopathy (DCM).


METHODS
Ninety-four patients with non-ischemic DCM underwent I-123 MIBG imaging for assessing cardiac sympathetic innervation and equilibrium radionuclide angiography. Mean phase angles and SD of the phase histogram were computed for both right ventricular (RV) and left ventricular (LV). Phase measures of interventricular (RV-LV) and intraventricular (SD-RV and SD-LV) asynchrony were computed.


RESULTS
Most patients were receiving beta-blockers (89%) and angiotensin-converting enzyme inhibitors (88%). One patient (1%) was lost to follow-up, six had cardiac death (6.4%), eight had heart transplantation (8.6%), and seven had unplanned hospitalization for heart failure (7.5%; mean follow-up: 37 +/- 16 months). Patients with poor clinical outcome were older, had higher The New York Heart Association functional class, impaired right ventricular ejection fraction and left ventricular ejection fraction, and impaired cardiac I-123 MIBG uptake. On multivariate analysis, I-123 MIBG heart-to-mediastinum (H/M) uptake ratio <1.6 was the only predictor of both primary (cardiac death or heart transplantation, RR = 7.02, p < 0.01) and secondary (cardiac death, heart transplantation, or recurrent heart failure, RR = 8.10, p = 0.0008) end points.


CONCLUSIONS
In patients receiving modern medical therapy involving beta-blockers, I-123 MIBG uptake, but not intra-LV asynchrony, was predictive of clinical outcome. The impact of beta-blockers on the prognostic value of ventricular asynchrony remains to be clarified.
Manrique
Alain
A
Nuclear Medicine, Rouen University Hospital-Henri Becquerel Center, 1 rue d'Amiens, 76038, Rouen, France. alain.manrique@univ-rouen.fr
Bernard
Mathieu
M
Hitzel
Anne
A
Bauer
Fabrice
F
Ménard
Jean-François
JF
Sabatier
Rémi
R
Jacobson
Arnold
A
Véra
Pierre
P
Agostini
Denis
D
D019797:3-Iodobenzylguanidine / Q000493:pharmacokinetics; D002311:Cardiomyopathy, Dilated / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*; D005260:Female; D006321:Heart / Q000294:innervation* / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011877:Radionuclide Imaging; D012189:Retrospective Studies; D013564:Sympathetic Nervous System; D016276:Ventricular Function
D019797:3-Iodobenzylguanidine