Akutsu Yasushi, Kaneko Kyouichi, Kodama Yusuke, Li Hui-Ling, Kawamura Mitsuharu, Asano Taku, Tanno Kaoru, Shinozuka Akira, Gokan Takehiko, Kobayashi Youichi
Division of Cardiology, Department of Medicine, Showa University School of Medicine, Tokyo, Japan.
J Nucl Med. 2009 Jan;50(1):61-7. doi: 10.2967/jnumed.108.055194. Epub 2008 Dec 17.
Severe left ventricular dysfunction or cardiac sympathetic nervous system (SNS) abnormality predicts cardiac death in various heart diseases, including arrhythmogenic disorders. However, it is not clear whether SNS abnormality predicts sudden cardiac death during long-term follow-up in patients with a history of ventricular tachyarrhythmia. We hypothesized that SNS abnormality would be associated with recurrent ventricular arrhythmic events.
123I-metaiodobenzylguanidine (MIBG) scintigraphy was performed on 86 patients (mean age+/-SD, 46+/-19 y, 65.1% men) with a history of ventricular tachycardia or fibrillation. 123I-MIBG (111 MBq) was intravenously administered under resting conditions, and planar images were obtained 15 min and 4 h later (anterior view for 6 min; 512x512 matrices; zoom ratio, 1.0). SNS activity was assessed using the heart-to-mediastinum ratio on delayed imaging.
During about 11 y of follow-up (mean+/-SD, 5.2+/-3.7 y), 3 patients (3.5%) had sudden cardiac death and 21 patients (24.4%) had sustained ventricular tachyarrhythmic events. SNS abnormality, defined as a heart-to-mediastinum ratio of less than 2.8, and left ventricular dysfunction, defined as a left ventricular ejection fraction of less than 50%, were associated with sudden cardiac death or recurrent ventricular tachyarrhythmic events (18/40 patients [45%] with SNS abnormality, vs. 6/46 patients [13%] without, P=0.004; 9/15 patients [60%] with left ventricular dysfunction, vs. 15/71 patients [21.1%] without, P=0.008). After adjustment for potential confounding variables such as age, sex, coronary risk factors, medication use, history of structural heart disease, and left ventricular function, SNS abnormality was a powerful predictor of recurrent arrhythmic events, with a hazard ratio of 3.6 [95% confidence interval, 1.4-9.2, P=0.007]). Further, SNS abnormality had incremental and additive prognostic power in combination with left ventricular dysfunction, with an adjusted hazard ratio of 4.4 [95% confidence interval, 1.9-9.9, P<0.0001]).
SNS abnormality predicted recurrent ventricular tachyarrhythmic events during long-term follow-up. 123I-MIBG scintigraphic evaluations for SNS abnormality may be an option for screening patients at high risk for sudden cardiac death.
严重左心室功能障碍或心脏交感神经系统（SNS）异常可预测包括致心律失常性疾病在内的各种心脏病的心脏死亡。然而，尚不清楚SNS异常是否能预测有室性快速心律失常病史患者在长期随访期间的心脏性猝死。我们假设SNS异常与复发性室性心律失常事件有关。
对86例有室性心动过速或颤动病史的患者（平均年龄±标准差，46±19岁，男性占65.1%）进行了123I-间碘苄胍（MIBG）闪烁显像。在静息状态下静脉注射123I-MIBG（111 MBq），并在15分钟和4小时后获取平面图像（前位视图6分钟；512×512矩阵；放大率，1.0）。使用延迟显像时的心脏与纵隔比值评估SNS活性。
在约11年的随访期间（平均±标准差，5.2±3.7年），3例患者（3.5%）发生心脏性猝死，21例患者（24.4%）发生持续性室性快速心律失常事件。SNS异常定义为心脏与纵隔比值小于2.8，左心室功能障碍定义为左心室射血分数小于50%，均与心脏性猝死或复发性室性快速心律失常事件相关（40例SNS异常患者中有18例[45%]，无SNS异常的46例患者中有6例[13%]，P=0.004；15例左心室功能障碍患者中有9例[60%]，无左心室功能障碍的71例患者中有15例[21.1%]，P=0.008）。在对年龄、性别、冠状动脉危险因素、药物使用、结构性心脏病史和左心室功能等潜在混杂变量进行调整后，SNS异常是复发性心律失常事件的有力预测指标，风险比为3.6[95%置信区间，1.4-9.2，P=0.007]）。此外，SNS异常与左心室功能障碍联合具有递增和相加的预后价值，调整后的风险比为4.4[95%置信区间，1.9-9.9，P<0.0001]）。
SNS异常可预测长期随访期间复发性室性快速心律失常事件。对SNS异常进行123I-MIBG闪烁显像评估可能是筛查心脏性猝死高危患者的一种选择。
