Wabich Elżbieta, Dorniak Karolina, Zienciuk-Krajka Agnieszka, Nowak Radosław, Raczak Grzegorz, Daniłowicz-Szymanowicz Ludmiła
Department of Cardiology and Electrotherapy, Medical University of Gdansk, Dębinki 7 St., 80-211 Gdansk, Poland.
Department of Noninvasive Cardiac Diagnostics, Medical University of Gdansk, Gdansk, Poland.
J Cardiol. 2021 May;77(5):475-481. doi: 10.1016/j.jjcc.2020.11.004. Epub 2020 Nov 24.
The prognostic value of myocardial fibrosis in patients with hypertrophic cardiomyopathy (HCM) has been well-established. Although cardiac magnetic resonance (CMR) is the method of choice in its revealing as the presence of late gadolinium enhancement (LGE), this technique still has limited availability in daily clinical practice. Two-dimensional speckle tracking echocardiography (2D STE) seems to be helpful in verification which HCM patient has the highest probability of LGE presence and hence needs to be qualified to CMR. While the majority of HCM patients have a patchy pattern of myocardial fibrosis, the aim of this study was to evaluate whether segmental rather than global longitudinal strain is more accurate in the identification of the presence of LGE.
Forty-six HCM patients had transthoracic echocardiography and CMR imaging performed. Each patient had global longitudinal strain and rotation parameters calculated, as well as segmental analyses for wall thickness, longitudinal strain, and LGE presence based on 736 segments of the left ventricle (LV). The presence of LGE in CMR was confirmed on a per-segment basis, which was similar to LV segments in the echocardiographic examination. All patients were divided into two groups according to the CMR result: LGE (+) and LGE (-).
Receiver-operating characteristic analyses identified peak global longitudinal strain and peak twisting velocity with the cut-off values -14.4% and 116°/s respectively as the accurate predictors of LGE presence in CMR, whereas segmental longitudinal strain of -12.5% cut-off value had the highest area under the curve value (87.4%, confidence interval 84.5-90.3%), with 93.7% sensitivity, 86.5% negative predictive value, and 55% specificity.
Segmental longitudinal strain with the cut-off value of -12.5% has the highest discriminatory power for LGE presence and seems to be more adequate than global speckle tracking parameters in identification of HCM patients with strong indications for CMR for more accurate risk stratification.
心肌纤维化在肥厚型心肌病（HCM）患者中的预后价值已得到充分证实。尽管心脏磁共振成像（CMR）是显示晚期钆增强（LGE）存在的首选方法，但该技术在日常临床实践中的可用性仍然有限。二维斑点追踪超声心动图（2D STE）似乎有助于验证哪些HCM患者存在LGE的可能性最高，因此需要进行CMR检查。虽然大多数HCM患者存在斑片状心肌纤维化，但本研究的目的是评估节段性而非整体纵向应变在识别LGE存在方面是否更准确。
对46例HCM患者进行了经胸超声心动图和CMR成像检查。计算每位患者的整体纵向应变和旋转参数，并基于左心室（LV）的736个节段对室壁厚度、纵向应变和LGE存在情况进行节段分析。CMR中LGE的存在是在每个节段的基础上确定的，这与超声心动图检查中的LV节段相似。根据CMR结果将所有患者分为两组：LGE（+）组和LGE（-）组。
受试者工作特征分析确定，整体纵向应变峰值和扭转速度峰值分别以-14.4%和116°/s的临界值作为CMR中LGE存在的准确预测指标，而临界值为-12.5%的节段性纵向应变的曲线下面积值最高（曲线下面积值为87.4%，置信区间为84.5-90.3%），敏感性为93.7%，阴性预测值为86.5%，特异性为55%。
临界值为-12.5%的节段性纵向应变对LGE存在具有最高的鉴别能力，在识别有强烈CMR指征的HCM患者以进行更准确的风险分层方面似乎比整体斑点追踪参数更合适。
