Prevalence of Potential Retrograde Embolization Pathways in the Proximal Descending Aorta in Stroke Patients and Controls
Prevalence of Potential Retrograde Embolization Pathways in the Proximal Descending Aorta in Stroke Patients and Controls
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DOI：
10.1159/000369001
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发表时间：
2014-01-01
影响因子：
2.9
通讯作者：
Harloff, Andreas
中科院分区：
文献类型：
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作者：
Wehrum, Thomas;Kams, Miriam;Harloff, Andreas
背景：降主动脉近端(DAO)的逆行舒张期血流将复杂的斑块(厚4 mm)与供脑的主动脉上动脉连接起来，可能构成卒中的来源。然而，只有来自高危人群(隐源性卒中患者伴主动脉粥样硬化<3 mm)的这种潜在卒中机制的流行率的数据是可用的。我们的目标是量化这一机制在无卒中病史的常规诊断和对照后未选定的隐源性卒中患者中的频率。方法：前瞻性纳入88例患者(67例卒中患者，21例心脏对照)。主动脉3DT1W加权亮血MRI显示复杂DAO动脉粥样硬化斑块。心电触发和导航仪导航的4D Flow MRI可以测量体内时间分辨的3D血流。潜在的逆行栓塞途径被定义为DAO内复杂斑块和逆行血流同时到达(A)左锁骨下动脉、(B)左颈总动脉或(C)头臂干出口。将2D斑块图像导入3D血流可视化软件，分析这些通路的出现频率。结果：复杂DAO斑块在卒中患者中的发生率为46.3%(44/31/67)，对照组为19.1%(4/21)；P=0.039)，尤其是老年患者(60岁组29/46(63.04%)，41个斑块；60岁组2/21(9.14%)，60岁组3个斑块(p<；0.001))。与我们的假设相反，无论两组患者是否存在程度相似的斑块(26+/-14 mm vs.32+/-18 mm；p=0.114)，DAO处的舒张期血流均逆行。因此，只有中风患者中复杂DAO斑块的高患病率导致潜在的逆行栓塞率是对照组的三倍(22/67(32.8%)比2/21(9.5%)；p=0.048)。结论：本研究揭示了降主动脉内逆行血流不仅在卒中患者中是一种普遍现象。潜在的逆行栓塞途径的存在主要取决于左锁骨下动脉出口后0~30 mm处是否有复杂斑块的出现，从而暴露于血流逆转。综上所述，我们的研究结果表明，在卒中患者中，潜在的逆行栓塞途径的出现频率明显更高，这表明这种机制可能在逆行脑栓塞中起作用。(C)2014年S.Karger AG，巴塞尔
Background: Retrograde diastolic blood flow in the proximal descending aorta (DAo) connecting complex plaques (>= 4 mm thick) with brain-supplying supra-aortic arteries may constitute a source of stroke. Yet, data only from high-risk populations (cryptogenic stroke patients with aortic atheroma >= 3 mm) regarding the prevalence of this potential stroke mechanism are available. We aimed to quantify the frequency of this mechanism in unselected patients with cryptogenic stroke after routine diagnostics and controls without a history of stroke. Methods: 88 patients (67 stroke patients, 21 cardiac controls) were prospectively included. 3D T1-weighted bright blood MRI of the aorta was applied for the detection of complex DAo atheroma. ECG-triggered and navigator-gated 4D flow MRI allowed measuring time-resolved 3D blood flow in vivo. Potential retrograde emboliza-tion pathways were defined as the co-occurrence of complex plaques and retrograde blood flow in the DAo reaching the outlet of (a) the left subclavian artery, (b) the left common carotid artery, or/and (c) the brachiocephalic trunk. The frequency of these pathways was analyzed by importing 2D plaque images into 3D blood flow visualization software. Results: Complex DAo plaques were more frequent in stroke patients (44 in 31/67 patients (46.3%) vs. 5 in 4/21 controls (19.1%); p = 0.039), especially in older patients (29/46 (63.04%) patients >= 60 years of age with 41 plaques vs. 2/21 (9.14%) patients < 60 years of age with 3 plaques; p < 0.001). Contrary to our assumption, retrograde diastolic blood flow at the DAo occurred in every patient irrespective of the existence of plaques with a similar extent in both groups (26 +/- 14 vs. 32 +/- 18 mm; p = 0.114). Therefore, only the higher prevalence of complex DAo plaques in stroke patients resulted in a three times higher frequency of potential retrograde embolization pathways compared to controls (22/67 (32.8%) vs. 2/21 (9.5%) controls; p = 0.048). Conclusions: This study revealed that retrograde flow in the descending aorta is a common phenomenon not only in stroke patients. The existence of potential retrograde embolization pathways depends mainly on the occurrence of complex plaques in the area 0 to similar to 30 mm behind the outlet of the left subclavian artery, which is exposed to flow reversal. In conclusion, we have shown that the frequency of potential retrograde embolization pathways was significantly higher in stroke patients suggesting that this mechanism may play a role in retrograde brain embolism. (C) 2014 S. Karger AG, Basel