Claridge Simon, Mennuni Silvia, Jackson Thomas, Behar Jonathan M, Porter Bradley, Sieniewicz Benjamin, Bostock Julian, O'Neill Mark, Murgatroyd Francis, Gill Jaswinder, Carr-White Gerald, Chiribiri Amedeo, Razavi Reza, Chen Zhong, Rinaldi Christopher Aldo
Department of Imaging Sciences and Biomedical Engineering, King's College London, London, UK.
Department of Cardiology, Guy's and St Thomas' Hospital Trust, London, UK.
J Cardiovasc Electrophysiol. 2017 Jul;28(7):785-795. doi: 10.1111/jce.13226. Epub 2017 Jun 9.
The role of implantable cardioverter defibrillators (ICDs) in nonischemic cardiomyopathy is unclear and better risk-stratification is required. We sought to determine if T1 mapping predicts appropriate defibrillator therapy in patients with nonischemic cardiomyopathy. We studied a mixed cohort of ischemic and nonischemic patients to determine whether different cardiac magnetic resonance (CMR) applications (T1 mapping, late gadolinium enhancement, and Grayzone) were selectively predictive of therapies for the different arrhythmic substrates.
We undertook a prospective longitudinal study of consecutive patients receiving defibrillators in a tertiary cardiac center. Participants underwent CMR myocardial tissue characterization using T1 mapping and conventional CMR scar assessment before device implantation. QRS duration and fragmentation on the surface electrocardiogram were also assessed. The primary endpoint was appropriate defibrillator therapy. One-hundred thirty patients were followed up for a median of 31 months (IQR ± 9 months). In nonischemic patients, T1 was the sole predictor of the primary endpoint (hazard ratio [HR] 1.12 per 10 millisecond increment in value [95% confidence interval [CI] 1.04-1.21; P ≤ 0.01]). In ischemic patients, Grayzone was the strongest predictor of appropriate therapy (HR 1.34 per 1% left ventricular increment in value [95% CI 1.03-1.76; P = 0.03]). QRS fragmentation correlated well with myocardial scar core (receiver operating characteristic area under the curve [ROC AUC] 0.64; P = 0.02) but poorly with T1 (ROC AUC 0.4) and did not predict appropriate therapy.
In the medium-long term, T1 mapping was the only independent predictor of therapy in nonischemic patients, whereas Grayzone was a better predictor in ischemic patients. These findings suggest a potential role for T1 mapping in the selection of patients for ICDs in a nonischemic population.
植入式心脏复律除颤器（ICD）在非缺血性心肌病中的作用尚不清楚，需要更好的风险分层。我们试图确定T1 mapping是否能预测非缺血性心肌病患者的适当除颤器治疗。我们研究了一组缺血性和非缺血性患者的混合队列，以确定不同的心脏磁共振（CMR）应用（T1 mapping、延迟钆增强和Grayzone）是否能选择性地预测不同心律失常基质的治疗方法。
我们在一家三级心脏中心对连续接受除颤器治疗的患者进行了一项前瞻性纵向研究。参与者在植入设备前使用T1 mapping和传统CMR瘢痕评估进行CMR心肌组织特征分析。还评估了体表心电图上的QRS波时限和碎裂情况。主要终点是适当的除颤器治疗。130名患者接受了中位31个月（四分位间距±9个月）的随访。在非缺血性患者中，T1是主要终点的唯一预测因子（每增加10毫秒值的风险比[HR]为1.12[95%置信区间[CI]1.04-1.21；P≤0.01]）。在缺血性患者中，Grayzone是适当治疗的最强预测因子（每增加1%左心室值的HR为1.34[95%CI 1.03-1.76；P=0.03]）。QRS波碎裂与心肌瘢痕核心相关性良好（曲线下受试者操作特征面积[ROC AUC]为0.64；P=0.02），但与T1相关性较差（ROC AUC为0.4），且不能预测适当治疗。
从中长期来看，T1 mapping是非缺血性患者治疗的唯一独立预测因子，而Grayzone在缺血性患者中是更好的预测因子。这些发现表明T1 mapping在非缺血人群中选择ICD患者方面具有潜在作用。
