2D延迟增强磁共振成像预测外科治疗房颤转复疗效临床研究

Application of 2D late gadolinium enhancement magnetic resonance imaging in the prediction of the outomes of surgical treatment of atrial fibrillation

目的通过行2D延迟增强(LGE)磁共振成像(MRI)对风湿性心脏病合并持续性心房纤颤(AF)的患者进行术前图像扫描,检测左房纤维化程度、左房前后径,寻找能够有效预测房颤患者射频消融术后转复率和复发率的可靠指标。方法共有30名患者纳入本研究,术前1天接受LGE-MRI扫描评估纤维化情况,在轴位像上将左心房划分为8个象限,根据延迟强化所表现的程度及范围,运用图像软件将左心房纤维化程度分为4级。所有患者左心房三维电解剖标测(CARTO)图像均在手术前完成并与MRI图像进行比较。结果术前根据MRI图像增强的范围分级,0级共4例,Ⅰ级共10例,Ⅱ级共10例,Ⅲ级共6例。CARTO分级0级共4例,Ⅰ级共9例,Ⅱ级共11例,Ⅲ级共6例,LGE-MRI对纤维化诊断准确率为83.3%(25/30),与CARTO分级间检验一致性好(Kappa=0.77,P<0.01)。LGE-MRI分级0级的患者未出现房颤复发(0%),Ⅰ级有1例出现房颤复发(10%),Ⅱ级患者有2例复发(20%),Ⅲ级患者有2例复发(33%)(P<0.05),经逐步Cox回归分析得出,术前纤维化程度是术后早期房颤复发独立危险因素(P=0.02)。结论LGE-MRI能提供一种非侵入性的方式评估左心房心肌纤维化程度,并且有可能成为预测外科射频消融术后房颤复发的临床术前检查。

Objective To detect the degree of left atrial fibrosis and left anterior posterior diameter in patients with rheumatic heart disease complicated with persistent atrial fibrillation by 2D late gadolinium enhancement MRI(LGE-MRI)before surgery,and to find a reliable index that can effectively predict the recovery rate and recurrence rate of atrial fibrillation after radiofrequency ablation.Methods A total of 30 patients were enrolled in this study,who received LGE-MRI scan before surgery to evaluate the fibrosis situa tion.The left atrium was divided into 8 quadrants by axial image.According to the degree and range of delayed enhancement,the degree of left atrial fibrosis was divided into four stage by the image software.CARTO images of all patients were completed before surgery and compared with MRI images.Results Classification was based on the scope of preoperative MRI image enhancement,with four cases of stage 0,10 cases of stageⅠ,10 cases of stageⅡ,and 6 cases of stageⅢ.With CARTO classification,there were 4 cases of stage 0,9 ca ses of stageⅠ,11 cases of stageⅡ,and 6 cases of stageⅢ.The diagnostic accuracy of the LGE-MRI atrial fibrosis was 83.3%(25/30),of which the correlation was good(Kappa=0.77,P<0.01).No recurrence of AF were found in patients with LGE-MRI grade 0(0%),but there were 1(10%),2(10%),2(33%)cases of AF recurrence in stageⅠ,Ⅱ,Ⅲrespectively(P<0.05).Stepwise Cox regression analysis showed that preoperative fibrosis degree was an independent risk factor for early postoperative AF recurrence(P=0.02).Con clusion LGE-MRI provides a non-invasive way to assess the extent of myocardial fibrosis in the left atrium and may become a poten tial preoperative clinical examination to predict recurrence of atrial fibrillation after surgical radiofrequency ablation.