Ge Lan, Xu Yawei, Li Jun, Li Yuan, Xi Yifeng, Wang Xinyan, Wang Jing, Mu Yang, Wang Hongsen, Lu Xu, Guo Jun, Chen Zengsheng, Chen Tao, Chen Yundai
Medical School of Chinese PLA, 28 Fuxing Road, Haidian District, Beijing 100853, China.
Senior Department of Cardiology, the Sixth Medical Center of PLA General Hospital, 6 Fucheng Road, Haidian District, Beijing 100048, China.
Heliyon. 2024 Feb 23;10(5):e26792. doi: 10.1016/j.heliyon.2024.e26792. eCollection 2024 Mar 15.
Contrast retention (CR) is an important predictor of left atrial appendage thrombus (LAAT) and stroke in patients with non-valvular atrial fibrillation (AF). We sought to explore the underlying mechanisms of CR using computational fluid dynamic (CFD) simulations.
A total of 12 patients with AF who underwent both cardiac computed tomography angiography (CTA) and transesophageal echocardiography (TEE) before left atrial appendage occlusion (LAAO) were included in the study. The patients were allocated into the CR group or non-CR group based on left atrial appendage (LAA) angiography. Patient-specific models were reconstructed to evaluate time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI), relative residence time (RRT), and endothelial cell activation potential (ECAP). Additionally, the incidence of thrombosis was predicted using residence time (RT) at different time-points.
TAWSS was lower [median (Interquartile Range) 0.27 (0.19-0.47) vs 1.35 (0.92-1.79), p < 0.001] in LAA compared to left atrium. In contrast, RRT [1438 (409.70-13869) vs 2.23 (1.81-3.14), p < 0.001] and ECAP [122.70 (30.01-625.70) vs 0.19 (0.16-0.27), p < 0.001)] was higher in the LAA. The patients in the CR group had significantly higher RRT [(mean ± SD) 16274 ± 11797 vs 639.70 ± 595.20, p = 0.009] and ECAP [610.80 ± 365.30 vs 54.26 ± 54.38, p = 0.004] in the LAA compared to the non-CR group. Additionally, patients with CR had a wider range of thrombus-prone regions [0.44(0.27-0.66)% vs 0.05(0.03-0.27)%, p = 0.009] at the end of the 15th cardiac cycle.
These findings suggest that CR might be an indicator of high-risk thrombus formation in the LAA. And CT-based CFD simulation may be a feasible substitute for the evaluation of LAA thrombotic risk in patients with AF, especially in patients with CR.
对比剂滞留（CR）是非瓣膜性心房颤动（AF）患者左心耳血栓（LAAT）和中风的重要预测指标。我们试图通过计算流体动力学（CFD）模拟来探索CR的潜在机制。
本研究纳入了12例在左心耳封堵（LAAO）术前接受心脏计算机断层扫描血管造影（CTA）和经食管超声心动图（TEE）检查的AF患者。根据左心耳（LAA）血管造影将患者分为CR组或非CR组。重建患者特异性模型以评估时间平均壁面切应力（TAWSS）、振荡切变指数（OSI）、相对停留时间（RRT）和内皮细胞激活潜能（ECAP）。此外，使用不同时间点的停留时间（RT）预测血栓形成的发生率。
与左心房相比，LAA中的TAWSS较低[中位数（四分位间距）0.27（0.19 - 0.47）vs 1.35（0.92 - 1.79），p < 0.001]。相比之下，LAA中的RRT[1438（409.70 - 13869）vs 2.23（1.81 - 3.14），p < 0.001]和ECAP[122.70（30.01 - 625.70）vs 0.19（0.16 - 0.27），p < 0.001]较高。与非CR组相比，CR组患者LAA中的RRT[（均值±标准差）16274±11797 vs 639.70±595.20，p = 0.009]和ECAP[610.80±365.30 vs 54.26±54.38，p = 0.004]显著更高。此外，在第15个心动周期末，CR患者的血栓易形成区域范围更广[0.44（0.27 - 0.66）% vs 0.05（0.03 - 0.27）%，p = 0.009]。
这些发现表明CR可能是LAA中高危血栓形成的一个指标。基于CT的CFD模拟可能是评估AF患者LAA血栓形成风险的一种可行替代方法，尤其是对于CR患者。
