Zhou Di, Zhang Huaying, Yang Wenjing, Wang Yining, Zhu Leyi, Jiang Mengdi, Xu Jing, Teng Fei, Zhao Xinxiang, Zhu Shaocheng, Liu Doudou, Zhang Qiang, Sirajuddin Arlene, Arai Andrew E, Zhao Shihua, Lu Minjie
Department of Magnetic Resonance Imaging, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
Department of Radiology, Fuwai Hospital, Chinese Academy of Medical Sciences, Shenzhen, China.
Radiology. 2025 Sep;316(3):e243427. doi: 10.1148/radiol.243427.
Background MRI-derived arrhythmogenic substrate, including late gadolinium enhancement (LGE) and extracellular volume fraction (ECV), is indicative of sudden cardiac death (SCD) risk in nonischemic dilated cardiomyopathy (DCM). The relative prognostic value of LGE and ECV remains unclear. Purpose To evaluate the performance of LGE and T1 mapping in predicting SCD in patients with DCM and to explore clinical implementation. Materials and Methods This study enrolled 1105 patients with DCM who underwent cardiac MRI at four centers. The data were analyzed in a development cohort ( = 837, single center) and an external validation cohort ( = 268, multicenter). The primary end point comprised SCD, appropriate implantable cardioverter-defibrillator shock, and resuscitated cardiac arrest. The secondary end point comprised heart failure-related death, heart transplant, and left ventricle (LV) assist device implantation. Risk algorithms and a clinical workflow for SCD risk assessment were developed based on validated MRI predictors. Results In the development cohort, 78 patients reached the primary end point and 120 reached the secondary end point over a median follow-up of 58.3 months. In the adjusted analysis, LGE of at least 7.2% of the LV mass (hazard ratio [HR], 4.75 [95% CI: 2.91, 7.74]; < .001), an ECV of at least 31.8% (HR, 2.91 [95% CI: 1.63, 5.22]; = .001), and a native T1 score of at least 2.1 (HR, 1.69 [95% CI: 1.04, 2.74]; = .04) were associated with SCD-related events. Patients with an ECV of at least 31.8% and no LGE were at a higher risk of SCD events compared with those with an ECV less than 31.8% and presence of LGE of less than 7.2% or midwall and/or focal LGE. Patients with an LV ejection fraction greater than 35%, LGE less than 7.2%, and an ECV less than 31.8% exhibited a low risk of SCD, with an annual event rate of 0.2%. Patients with LGE of at least 7.2% exhibited a high risk of SCD-related events (annual event rate, 4.65%) irrespective of ECV and native T1 value and LGE distribution and/or pattern. Conclusion In nonischemic DCM, LGE of at least 7.2% was strongly predictive of SCD risk irrespective of distribution and pattern. ECV significantly enhanced risk stratification, particularly in patients with negative or focal and/or midwall LGE. © RSNA, 2025 See also the editorial by Sakuma in this issue.
磁共振成像（MRI）衍生的致心律失常基质，包括钆延迟强化（LGE）和细胞外容积分数（ECV），可提示非缺血性扩张型心肌病（DCM）患者的心源性猝死（SCD）风险。LGE和ECV的相对预后价值仍不明确。目的：评估LGE和T1 mapping在预测DCM患者SCD方面的性能，并探索其临床应用。材料与方法：本研究纳入了在四个中心接受心脏MRI检查的1105例DCM患者。数据在一个开发队列（n = 837，单中心）和一个外部验证队列（n = 268，多中心）中进行分析。主要终点包括SCD、合适的植入式心律转复除颤器电击以及复苏的心脏骤停。次要终点包括心力衰竭相关死亡、心脏移植和左心室（LV）辅助装置植入。基于经过验证的MRI预测指标，开发了SCD风险评估的风险算法和临床工作流程。结果：在开发队列中，经过58.3个月的中位随访，78例患者达到主要终点，120例患者达到次要终点。在调整分析中，LGE至少占LV质量的7.2%（风险比[HR]，4.75 [95% CI：2.91，7.74]；P <.001）、ECV至少为31.8%（HR，2.91 [95% CI：1.63，5.22]；P =.001）以及固有T1值至少为2.1（HR，1.69 [95% CI：1.04，2.74]；P =.04）与SCD相关事件相关。与ECV小于31.8%且LGE小于7.2%或中层壁和/或局灶性LGE的患者相比，ECV至少为31.8%且无LGE的患者发生SCD事件的风险更高。LV射血分数大于35%、LGE小于7.2%且ECV小于31.8%的患者SCD风险较低，年事件发生率为0.2%。无论ECV、固有T1值以及LGE分布和/或模式如何，LGE至少为7.2%的患者发生SCD相关事件的风险较高（年事件发生率，4.65%）。结论：在非缺血性DCM中，无论分布和模式如何，LGE至少为7.2%强烈预测SCD风险。ECV显著增强了风险分层，特别是在LGE为阴性或局灶性和/或中层壁LGE的患者中。© RSNA，2025 另见本期Sakuma的社论。
