Objectives The aim of this study was to analyze whether scar characterization could improve the risk stratification for life-threatening ventricular arrhythmias and sudden cardiac death (SCD).

Background Among patients with a cardiac resynchronization therapy (CRT) indication, appropriate defibrillator (CRT-D) therapy rates are low.

Methods Primary prevention patients with a class I indication for CRT were prospectively enrolled and assigned to CRT-D or CRT pacemaker according to physician’s criteria. Pre-procedure contrast-enhanced cardiac magnetic resonance was obtained and analyzed to identify scar presence or absence, quantify the amount of core and border zone (BZ), and depict BZ distribution. The presence, mass, and characteristics of BZ channels in the scar were recorded. The primary endpoint was appropriate defibrillator therapy or SCD.

Results 217 patients (39.6% ischemic) were included. During a median follow-up of 35.5 months (12 to 62 months), the primary endpoint occurred in 25 patients (11.5%) and did not occur in patients without myocardial scar. Among patients with scar (n = 125, 57.6%), those with implantable cardioverter-defibrillator (ICD) therapies or SCD exhibited greater scar mass (38.7 ± 34.2 g vs. 17.9 ± 17.2 g; p < 0.001), scar heterogeneity (BZ mass/scar mass ratio) (49.5 ± 13.0 vs. 40.1 ± 21.7; p = 0.044), and BZ channel mass (3.6 ± 3.0 g vs. 1.8 ± 3.4 g; p = 0.018). BZ mass (hazard ratio: 1.06 [95% confidence interval: 1.04 to 1.08]; p < 0.001) and BZ channel mass (hazard ratio: 1.21 [95% confidence interval: 1.10 to 1.32]; p < 0.001) were the strongest predictors of the primary endpoint. An algorithm based on scar mass and the absence of BZ channels identified 148 patients (68.2%) without ICD therapy/SCD during follow-up with a 100% negative predictive value.

Conclusions The presence, extension, heterogeneity, and qualitative distribution of BZ tissue of myocardial scar independently predict appropriate ICD therapies and SCD in CRT patients.

目的本研究的目的是分析疤痕特征是否可以改善危及生命的室性心律失常和心源性猝死（SCD）的危险分层。

背景技术在有心脏再同步治疗（CRT）指征的患者中，适当的除颤器（CRT-D）治疗率很低。

方法前瞻性招募一级预防为CRT的一级预防患者，并根据医生的标准分配至CRT-D或CRT起搏器。获得了术前对比增强的心脏磁共振，并进行了分析以鉴定疤痕的存在与否，量化核心和边界区（BZ）的数量并描绘BZ分布。记录疤痕中BZ通道的存在，质量和特征。主要终点是适当的除颤器治疗或SCD。

结果包括217例患者（39.6％缺血）。在35.5个月（12到62个月）的中位随访期间，主要终点发生在25例患者（11.5％）中，未发生在无心肌疤痕的患者中。在有疤痕的患者中（n = 125，57.6％），采用植入式心脏复律除颤器（ICD）疗法或SCD的患者表现出更大的疤痕质量（38.7±34.2 g vs. 17.9±17.2 g; p <0.001），疤痕异质性（BZ质量/疤痕质量比）（49.5±13.0对40.1±21.7; p = 0.044）和BZ通道质量（3.6±3.0 g对1.8±3.4 g; p = 0.018）。BZ质量（危险比：1.06 [95％置信区间：1.04至1.08]； p <0.001）和BZ通道质量（危险比：1.21 [95％置信区间：1.10至1.32]； p <0.001）是最强的预测指标主要端点的数量。

结论心肌瘢痕BZ组织的存在，扩展，异质性和定性分布可独立预测CRT患者的适当ICD治疗和SCD。