Comparison of the prognostic value of cardiac iodine-123 metaiodobenzylguanidine imaging and heart rate variability in patients with chronic heart failure: a prospective study.
OBJECTIVE
We sought to prospectively compare the prognostic value of cardiac iodine-123 (I-123) metaiodobenzylguanidine (MIBG) imaging with that of heart rate variability (HRV) in patients with mild-to-moderate chronic heart failure (HF).


BACKGROUND
Cardiac I-123 MIBG imaging, which reflects cardiac adrenergic nerve activity, provides prognostic information on chronic HF patients. Reduced HRV, indicating derangement in cardiac autonomic control, was also reported to be associated with a poor prognosis in chronic HF patients.


METHODS
At study entry, I-123 MIBG imaging and 24-h Holter monitoring were performed in 65 chronic HF outpatients with a radionuclide left ventricular ejection fraction <40%. The cardiac MIBG heart to mediastinum ratio (H/M) and washout rate (WR) were obtained from MIBG imaging. The time and frequency domain parameters of HRV were calculated from 24-h Holter recordings.


RESULTS
At a mean follow-up of 34 +/- 19 months, WR (p < 0.0001), H/M on the delayed image (p = 0.01), and normalized very-low-frequency power (n-VLFP) (p = 0.047) showed a significant association with the cardiac events (sudden death in 3 and hospitalization for worsening chronic HF in 10 patients) on univariate analysis. Multivariate analysis revealed that WR was the only independent predictor of cardiac events, although the predictive accuracy for the combination of abnormal WR and n-VLFP significantly increased, compared with that for abnormal WR (82% vs. 66%, p < 0.05).


CONCLUSIONS
Cardiac MIBG WR has a higher prognostic value than HRV parameters in patients with chronic HF. The combination of abnormal WR and n-VLFP would be useful to identify chronic HF patients at a higher risk of cardiac events.
Yamada
Takahisa
T
Division of Cardiology, Osaka Prefectural General Hospital, Japan. tyamada@gh.pref.osaka.jp
Shimonagata
Tsuyoshi
T
Fukunami
Masatake
M
Kumagai
Kazuaki
K
Ogita
Hisakazu
H
Hirata
Akio
A
Asai
Mitsutoshi
M
Makino
Nobuhiko
N
Kioka
Hidetaka
H
Kusuoka
Hideo
H
Hori
Masatsugu
M
Hoki
Noritake
N
D019797:3-Iodobenzylguanidine; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease; D015716:Electrocardiography, Ambulatory; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity; D016277:Ventricular Function, Left / Q000502:physiology
D019275:Radiopharmaceuticals; D019797:3-Iodobenzylguanidine