Arrhythmia Section, Cardiology Department, Thorax Institute, Hospital Clínic, Universitat de Barcelona, Barcelona, Catalonia, Spain.
Europace. 2012 Nov;14(11):1578-86. doi: 10.1093/europace/eus104. Epub 2012 May 4.
There is insufficient evidence to implant a combined cardiac resynchronization therapy (CRT) device with defibrillation capabilities (CRT-D) in all CRT candidates. The aim of the study was to assess myocardial scar size and its heterogeneity as predictors of sudden cardiac death (SCD) in CRT candidates.
A cohort of 78 consecutive patients with dilated cardiomyopathy and class I indication for CRT-D were prospectively enrolled. Before CRT-D implantation, a contrast-enhanced cardiac magnetic resonance (ce-CMR) was performed. The core and border zone (BZ) of the myocardial scar were characterized and quantified with a customized post-processing software. The first appropriate implantable cardioverter defibrillator (ICD) therapy was considered as a surrogate of SCD. During a mean follow-up of 25 months (25-75th percentiles, 15-34), appropriate ICD therapy occurred in 11.5% of patients. In a multivariate Cox proportional hazards regression model for clinical and ce-CMR variables, the scar mass percentage [hazards ratio (HR) per 1% increase 1.1 (1.06-1.15), P < 0.01], the BZ mass [HR per 1 g increase 1.06 (1.04-1.09), P < 0.01], and the BZ percentage of the scar [HR per 1% increase 1.06 (1.02-1.11), P < 0.01], were the only independent predictors of appropriate ICD therapy. Receiver-operating characteristic curve analysis showed that a scar mass <16% and a BZ < 9.5 g had a negative predictive value of 100%.
The presence, size, and heterogeneity of myocardial scar independently predict appropriate ICD therapies in CRT candidates. The ce-CMR-based scar analysis might help identify a subgroup of patients at relatively low risk of SCD.
对于所有心脏再同步治疗（CRT）候选者，植入具有除颤功能的 CRT 设备（CRT-D）的证据不足。本研究旨在评估心肌瘢痕大小及其异质性作为 CRT 候选者发生心脏性猝死（SCD）的预测因子。
连续纳入 78 例扩张型心肌病且 CRT-D 一级适应证的患者进行前瞻性研究。在植入 CRT-D 之前，进行对比增强心脏磁共振（ce-CMR）检查。使用定制的后处理软件对心肌瘢痕的核心区和边缘区（BZ）进行特征描述和定量分析。首次合适的植入式心脏复律除颤器（ICD）治疗被视为 SCD 的替代指标。在平均 25 个月（25-75 百分位，15-34 个月）的随访期间，11.5%的患者发生了合适的 ICD 治疗。在临床和 ce-CMR 变量的多变量 Cox 比例风险回归模型中，瘢痕质量百分比[每增加 1%的风险比（HR）1.1（1.06-1.15），P<0.01]、BZ 质量[每增加 1 g 的 HR 1.06（1.04-1.09），P<0.01]和瘢痕的 BZ 百分比[每增加 1%的 HR 1.06（1.02-1.11），P<0.01]是合适 ICD 治疗的唯一独立预测因子。受试者工作特征曲线分析显示，瘢痕质量<16%和 BZ<9.5 g 具有 100%的阴性预测值。
心肌瘢痕的存在、大小和异质性独立预测 CRT 候选者合适的 ICD 治疗。基于 ce-CMR 的瘢痕分析可能有助于识别 SCD 风险相对较低的患者亚组。
