Chen Xi, Chen Rui, Luo Xinyi, Wu Xinyi, Yang Yuelong, Du Zhicheng, Wei Xiaoyu, Wu Zhigang, Xu Yongzhou, Liu Hui
The Second School of Clinical Medicine, Southern Medical University, Guangzhou, China.
Department of Radiology, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China.
Cardiovasc Diagn Ther. 2022 Dec;12(6):767-778. doi: 10.21037/cdt-22-305.
Left atrial strain rate (LASR) is rarely used as an indicator of cardiovascular disorder prognosis in dilated cardiomyopathy (DCM). In the present study, we aimed to explore the prognostic value of the LASR in patients with severe idiopathic DCM [left ventricle ejection fraction (LVEF) <35%] using cardiac magnetic resonance feature tracking (CMR-FT).
A retrospective cohort study was performed. At the time of enrollment, patients who underwent cardiovascular magnetic resonance (CMR) imaging were selected for the study. Left atrium (LA) strain rate was measured in patients with severe idiopathic DCM from four-chamber and two-chamber views using a 3.0-T CMR scanner. The study endpoint was defined as a combination of all-cause death, implantable cardioverter-defibrillator (ICD), hospitalization due to cardiac failure, and heart transplantation. Cox model analyses were used to assess the statistical significance of the risk factors.
Fifty-eight patients with a confirmed diagnosis of severe idiopathic DCM were ultimately included in the analysis [mean age of 46 years; 41 (73%) men]. The median follow-up was 43 months (13-72 months). Adverse cardiovascular events occurred in 29 patients: all-cause death occurred in 15 participants (25.8%), ICD was performed in 5 participants (8.6%), heart failure hospitalization occurred in 8 participants (13.8%), and 1 participant (1.7%) underwent heart transplantation. From univariate analysis, the left atrium reservoir strain rate (LASRs) [HR 0.12; 95% CI (0.02, 0.55), P=0.007] and the left atrium booster pump strain rate (LASRa) [HR 3.21; 95% CI (1.08, 9.58), P=0.036] significantly predicted the association with cardiovascular events. In model 1 after adjusting for basic cardiovascular risk factors, including age, hypertension, diabetes mellitus, and N-terminal pro-brain natriuretic peptide (NT-proBNP), the LASRs [HR 0.12, 95% CI (0.02, 0.58), P=0.009] was assessed. The mitral valve regurgitation, LA maximum volume index, and LA diastatic volume index were added in model 2 based on model 1. LASRs [HR 0.13, 95% CI (0.02. 0.82) P=0.030] was the independent prediction factor after adjustment for model 1 and model 2. The LASRs had a good prognostic value with an area under the curve of receiver operating characteristic of 0.697 (0.617, 0.777) at 1 year, 0.716 (0.643, 0.788) at 3 years, 0.716 (0.651, 0.798) at 5 years and 0.703 (0.597, 0.809) at 7 years.
LA reservoir strain rate and active strain rate were powerful prognostic markers. The LASRs by MRI-FT provided independent prognostic value in patients with severe idiopathic DCM.
左心房应变率（LASR）在扩张型心肌病（DCM）中很少被用作心血管疾病预后的指标。在本研究中，我们旨在利用心脏磁共振特征追踪（CMR-FT）探索LASR在重度特发性DCM患者[左心室射血分数（LVEF）<35%]中的预后价值。
进行了一项回顾性队列研究。在入组时，选择接受心血管磁共振（CMR）成像的患者进行研究。使用3.0-T CMR扫描仪从四腔心和两腔心视图测量重度特发性DCM患者的左心房（LA）应变率。研究终点定义为全因死亡、植入式心律转复除颤器（ICD）、因心力衰竭住院和心脏移植的综合情况。采用Cox模型分析评估危险因素的统计学意义。
最终纳入分析的58例确诊为重度特发性DCM的患者[平均年龄46岁；41例（73%）为男性]。中位随访时间为43个月（13 - 72个月）。29例患者发生不良心血管事件：15例参与者（25.8%）发生全因死亡，5例参与者（8.6%）接受ICD植入，8例参与者（13.8%）因心力衰竭住院，1例参与者（1.7%）接受心脏移植。单因素分析显示，左心房储备应变率（LASRs）[风险比（HR）0.12；95%置信区间（CI）（0.02，0.55），P = 0.007]和左心房增强泵应变率（LASRa）[HR 3.21；95% CI（1.08，9.58），P = 0.036]显著预测了与心血管事件的关联。在调整了包括年龄、高血压、糖尿病和N末端脑钠肽前体（NT-proBNP）等基本心血管危险因素的模型1中，评估了LASRs[HR 0.12，95% CI（0.02，0.58），P = 0.009]。基于模型1，在模型2中加入二尖瓣反流、左心房最大容积指数和左心房舒张末期容积指数。在调整模型1和模型2后，LASRs[HR 0.13，95% CI（0.02，0.82），P = 0.030]是独立预测因素。LASRs具有良好的预后价值，1年时受试者工作特征曲线下面积为0.697（0.617，0.777），3年时为0.716（0.643，0.788），5年时为0.716（0.651，0.798），7年时为0.703（0.597，0.809）。
左心房储备应变率和主动应变率是强大的预后标志物。通过MRI-FT测量的LASRs在重度特发性DCM患者中提供了独立的预后价值。
