Significance of performing 123I-metaiodobenzylguanidine myocardial scintigraphy at different times for the long-term prediction of cardiac events in patients with dilated cardiomyopathy.
OBJECTIVE
Although it has been reported that (123)I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy is useful for assessing the prognosis of dilated cardiomyopathy (DCM), there have been no reports regarding how interval MIBG imaging should be performed during follow-up. We investigated the significance of performing MIBG at different times for the long-term prediction of cardiac events in DCM patients.


METHODS
The participants were 36 DCM patients who did not sustain cardiac events for 2 years after beta-blocker induction. MIBG was performed 6 months and 2 years after beta-blocker induction and the images analyzed to obtain the extent score, severity score (SEV), and the washout rate. Echocardiography was performed at the same time.


RESULTS
Eight patients experienced a cardiac event during follow-up (cardiac death: two patients; heart failure requiring hospitalization: six patients). Although no significant difference was found in any MIBG parameters or left ventricular ejection fraction between patients who experienced a cardiac event and those who did not after 6 months, early extent score, early SEV, delayed SEV, and washout rate were found to be significantly higher for patients who experienced a cardiac event after 2 years. In multivariate analysis using Cox proportional hazard model, none of the MIBG parameters or left ventricular ejection fraction after 6 months was identified as a predictor of cardiac events. However, delayed SEV after 2 years (hazard ratio 1.067, P = 0.0435) was a significant predictor of cardiac events.


CONCLUSIONS
The study suggested that performing MIBG at least once every 2 years allows long-term prediction of cardiac events in the follow-up of DCM patients.
Nakanishi
Rine
R
Department of Cardiovascular Medicine, Toho University Omori Medical Center, 6-11-1 Omori-nishi, Ohta-ku, Tokyo 143-8541, Japan.
Fujimoto
Shinichiro
S
Utanohara
Yuko
Y
Takamura
Kazuhisa
K
Inoue
Aritomo
A
Yamashina
Shohei
S
Namiki
Atsushi
A
Yamazaki
Junichi
J
D019797:3-Iodobenzylguanidine; D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use; D000704:Analysis of Variance; D002311:Cardiomyopathy, Dilated / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000188:drug therapy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D055414:Myocardial Perfusion Imaging; D011379:Prognosis; D013997:Time Factors
D000319:Adrenergic beta-Antagonists; D019797:3-Iodobenzylguanidine