Department of Cardiology, University of Health Sciences, Tepecik Training and Research Hospital, Izmir, Turkey.
Department of Internal Medicine, University of Health Sciences, Tepecik Training and Research Hospital, Izmir, Turkey.
Echocardiography. 2021 Jun;38(6):825-833. doi: 10.1111/echo.15067. Epub 2021 May 4.
Cardiovascular iron load is the leading cause of morbidity and mortality in beta-thalassemia major (β-TM). However, many patients remain asymptomatic until the late stage. In this cross-sectional study, we investigated the role of three-dimensional (3D) echocardiography and endothelial dysfunction parameters in asymptomatic β-TM patients, and the relationship between these parameters and cardiac magnetic resonance imaging (MRI) T2* value.
A total of 51 asymptomatic β-TM patients receiving regular blood transfusions were divided into two groups based on cardiac MRI-T2* values (MRI-T2*<20 ms and ≥20 ms), which MRI-T2*<20 ms determines myocardial iron load and evaluated by two-dimensional (2D) and 3D-echocardiography including endothelial dysfunction parameters. The relationships between ferritin levels, 2D and 3D-echocardiography measurements, endothelial dysfunction parameters, and cardiac MRI-T2* values were investigated.
All left ventricle ejection fraction (LVEF) obtained by 2D-echocardiography were normal (≥50%). LVEF-3D (53.25 ± 2.33 vs. 58.81 + 1.02), SDI12 (6.53 ± 0.56 vs. 2.85 + 0.48), and SDI16 (7.65 ± 0.75 vs. 3.26 + 0.49) were significantly different and negatively correlated between groups with MRI-T2*<20 ms and ≥20 ms, respectively. Flow-mediated dilatation (FMD) (6.08% ± 0.34% vs. 14.46% ± 1.12), aortic strain (7.79% ± 2.19% vs. 12.76% ± 4.19), ferritin levels were significantly different and negatively correlated between groups with MRI-T2*<20 ms and ≥20 ms, respectively. Higher ferritin, SDI12/16 were significant independent predictors of MR-T2* < 20 ms. SDI16 > 5.5, SDI12 > 4.3 predicted MRI-T2*<20ms with a sensitivity of 92%, specificity of 81% (AUC 0.85, P < .001), and sensitivity of 92%, specificity of 78% (AUC 0.83, P < .001), respectively.
SDI12/16 calculated by 3D-echocardiography may be a promising predictors of cardiovascular iron load and, decreased LVEF-3D, FMD, and aortic strain might be good indicators of subclinical cardiovascular involvement of β-TM.
心血管铁负荷是导致重型β地中海贫血（β-TM）患者发病和死亡的主要原因。然而，许多患者直到晚期才出现症状。在这项横断面研究中，我们研究了三维（3D）超声心动图和内皮功能障碍参数在无症状β-TM 患者中的作用，以及这些参数与心脏磁共振成像（MRI）T2*值之间的关系。
根据心脏 MRI-T2值（MRI-T2<20ms 和≥20ms）将 51 例接受定期输血的无症状β-TM 患者分为两组，MRI-T2*<20ms 用于确定心肌铁负荷，并通过二维（2D）和 3D-超声心动图评估，包括内皮功能障碍参数。研究了铁蛋白水平、2D 和 3D-超声心动图测量值、内皮功能障碍参数与心脏 MRI-T2*值之间的关系。
所有通过 2D-超声心动图获得的左心室射血分数（LVEF）均正常（≥50%）。LVEF-3D（53.25±2.33 比 58.81+1.02）、SDI12（6.53±0.56 比 2.85+0.48）和 SDI16（7.65±0.75 比 3.26+0.49）在 MRI-T2*<20ms 和≥20ms 的两组之间差异有统计学意义，且呈负相关。两组间磁共振 T2*<20ms 和≥20ms 的血流介导的扩张（FMD）（6.08%±0.34%比 14.46%±1.12%）和主动脉应变（7.79%±2.19%比 12.76%±4.19%）差异有统计学意义，且呈负相关。铁蛋白水平、SDI12/16 在两组间差异有统计学意义，且呈负相关。较高的铁蛋白、SDI12/16 是 MRI-T2*<20ms 的独立显著预测因子。SDI16>5.5、SDI12>4.3 预测 MRI-T2*<20ms 的敏感性为 92%，特异性为 81%（AUC 0.85，P<0.001），敏感性为 92%，特异性为 78%（AUC 0.83，P<0.001）。
3D 超声心动图计算的 SDI12/16 可能是心血管铁负荷的有前途的预测因子，而降低的 LVEF-3D、FMD 和主动脉应变可能是β-TM 亚临床心血管受累的良好指标。
