Wessex Cardiothoracic Unit, Southampton University Hospitals NHS Trust, UK.
J Cardiovasc Electrophysiol. 2013 Apr;24(4):430-6. doi: 10.1111/jce.12035. Epub 2012 Dec 4.
The extent of left ventricular (LV) scar, characterized by late gadolinium enhancement cardiac MRI (LGE-CMR), has been shown to predict the occurrence of ventricular arrhythmias in implantable cardioverter defibrillator (ICD) recipients. However, the specificity of LGE-CMR for sudden cardiac death (SCD) versus non-SCD is unclear. The aim of this retrospective, observational study was to evaluate this relationship in a cohort of ICD recipients.
We included consecutive patients who had undergone LGE-CMR before ICD implantation over a 4-year period (2006-2009). Scar (defined as myocardium with a signal intensity ≥50% of the maximum in scar tissue) was characterized in terms of percent scar and number of transmural LV scar segments in a 17-segment model. The endpoints were appropriate ICD therapy and all-cause mortality. Sixty-four patients (average age 66 ± 11 years, 51 male, median LVEF 30%) were included. During 42 ± 13 months follow-up, appropriate ICD therapy occurred in 28 patients (44%), and 14 patients (22%) died. Number of transmural scar segments (P = 0.005) and percentage LV scar (P = 0.03) were both significantly associated with appropriate ICD therapy. However, neither number of transmural scar segments (P = 0.32) or percent LV scar (P = 0.59) was significantly associated with all-cause mortality.
In this observational study, in medium-term follow-up, the extent of LV scar characterized by LGE-CMR was strongly associated with the occurrence of spontaneous ventricular arrhythmias but not all-cause mortality. We hypothesize that scar quantification by LGE-CMR may be more specific for SCD than non-SCD, and may prove a valuable tool for the selection of patients for ICD therapy.
心脏磁共振（CMR）延迟钆增强（LGE-CMR）显示的左心室（LV）瘢痕程度可预测植入式心脏复律除颤器（ICD）患者发生室性心律失常。然而，LGE-CMR 对心脏性猝死（SCD）与非 SCD 的特异性尚不清楚。本回顾性观察性研究旨在评估 ICD 患者中的这种相关性。
我们纳入了 4 年内（2006 年至 2009 年）接受 LGE-CMR 检查后植入 ICD 的连续患者。瘢痕（定义为信号强度≥瘢痕组织中最大信号强度的 50%的心肌）采用 17 节段模型中的瘢痕百分比和透壁性 LV 瘢痕节段数来描述。终点为适当的 ICD 治疗和全因死亡率。64 例患者（平均年龄 66±11 岁，51 例男性，中位 LVEF 30%）入组。42±13 个月的随访期间，28 例（44%）患者发生了适当的 ICD 治疗，14 例（22%）患者死亡。透壁性瘢痕节段数（P=0.005）和 LV 瘢痕百分比（P=0.03）均与适当的 ICD 治疗显著相关。然而，透壁性瘢痕节段数（P=0.32）或 LV 瘢痕百分比（P=0.59）均与全因死亡率无显著相关性。
在这项观察性研究中，在中期随访中，LGE-CMR 显示的 LV 瘢痕程度与自发性室性心律失常的发生密切相关，但与全因死亡率无关。我们假设 LGE-CMR 对瘢痕的定量评估对 SCD 的特异性可能优于非 SCD，并且可能成为选择 ICD 治疗患者的有价值的工具。
