Significance of cardiac sympathetic nervous system abnormality for predicting vascular events in patients with idiopathic paroxysmal atrial fibrillation.
OBJECTIVE
Neuronal system activity plays an important role for the prognosis of patients with atrial fibrillation (AF). Using (123)I metaiodobenzylguanidine ((123)I-MIBG) scintigraphy, we investigated whether a cardiac sympathetic nervous system (SNS) abnormality would be associated with an increased risk of vascular events in patients with paroxysmal AF.


METHODS
(123)I-MIBG scintigraphy was performed in 69 consecutive patients (67 + or - 13 years, 62% men) with paroxysmal AF who did not have structural heart disease. SNS integrity was assessed from the heart to mediastinum (H/M) ratio on delayed imaging. Serum concentration of C-reactive protein (CRP) was measured before (123)I-MIBG study.


RESULTS
During a mean of 4.5 + or - 3.6 years follow-up, 19 patients had myocardial infarction, stroke or heart failure (range: 0.2-11.5 years). SNS abnormality (H/M ratio <2.7) and high CRP (> or = 0.3 mg/dl) were associated with the vascular events (58.3% in 14 of 24 patients with SNS abnormality vs 11.1% in 5 of 45 patients without SNS abnormality, p < 0.0001, 52.4% in 11 of 21 patients with high CRP vs 16.7% in 8 of 48 patients without high CRP, p < 0.0001). After adjustment for potential confounding variables such as age, left atrial dimension and left ventricular function, SNS abnormality was an independent predictor of vascular events with a hazard ratio of 4.1 [95% confidence interval (CI): 1.3-12.6, p = 0.014]. Further, SNS abnormality had an incremental and additive prognostic power in combination with high CRP with an adjusted hazard ratio of 4.1 (95% CI: 1.5-10.9, p = 0.006).


CONCLUSIONS
SNS abnormality is predictive of vascular events in patients with idiopathic paroxysmal AF.
Akutsu
Yasushi
Y
Division of Cardiology, Department of Medicine, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawaku, Tokyo 142-8666, Japan. hzn01233@s02.itscom.net
Kaneko
Kyouichi
K
Kodama
Yusuke
Y
Li
Hui-Ling
HL
Suyama
Jumpei
J
Shinozuka
Akira
A
Gokan
Takehiko
T
Kawamura
Mitsuharu
M
Asano
Taku
T
Hamazaki
Yuji
Y
Tanno
Kaoru
K
Kobayashi
Youichi
Y
D019797:3-Iodobenzylguanidine; D000368:Aged; D000369:Aged, 80 and over; D001281:Atrial Fibrillation / Q000097:blood / Q000209:etiology / Q000503:physiopathology*; D002097:C-Reactive Protein / Q000032:analysis; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000453:epidemiology*; D006801:Humans; D007457:Iodine Radioisotopes; D007564:Japan / Q000453:epidemiology; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000453:epidemiology* / Q000209:etiology; D011379:Prognosis; D011446:Prospective Studies; D019275:Radiopharmaceuticals; D012306:Risk; D020521:Stroke / Q000453:epidemiology* / Q000209:etiology; D013564:Sympathetic Nervous System / Q000503:physiopathology*
D007457:Iodine Radioisotopes; D019275:Radiopharmaceuticals; D019797:3-Iodobenzylguanidine; D002097:C-Reactive Protein