Garcia Brás Pedro, Aguiar Rosa Sílvia, Thomas Boban, Fiarresga António, Cardoso Isabel, Pereira Ricardo, Branco Gonçalo, Cruz Inês, Baquero Luís, Cruz Ferreira Rui, Mota Carmo Miguel, Rocha Lopes Luís
Department of Cardiology, Santa Marta Hospital, Lisbon, Portugal.
Department of Cardiology, Santa Marta Hospital, Lisbon, Portugal; Heart Center, Red Cross Hospital, Lisbon, Portugal.
Rev Port Cardiol. 2022 Jul;41(7):559-568. doi: 10.1016/j.repc.2022.03.003. Epub 2022 May 20.
Microvascular dysfunction is an often overlooked feature of hypertrophic cardiomyopathy (HCM). Our aim was to assess the association between microvascular dysfunction, wall thickness, tissue characteristics and myocardial deformation in HCM patients, by analyzing individual myocardial segments.
Prospective assessment including cardiac magnetic resonance to assess wall thickness, T1 and T2 mapping, extracellular volume, late gadolinium enhancement (LGE) and stress perfusion. Results were stratified according to the 16 American Heart Association segments.
Seventy-five patients were recruited (1200 segments), 63% male, mean age 54.6±14.8 years, maximal wall thickness of 20.22±4.6 mm. Among the 424 segments (35%) with perfusion defects, 24% had defects only in the endocardial layer and 12% in both endocardial and epicardial layers. Perfusion defects were more often detected in hypertrophied segments (64%). Among the 660 segments with normal wall thickness, 19% presented perfusion defects. Independently of wall thickness, segments with perfusion defects had a higher T1 (β-estimate 30.28, p<0.001), extracelluar volume (β-estimate 1.50, p<0.001) and T2 (β-estimate 0.73, p<0.001) and had late gadolinium enhancement more frequently (odds ratio 4.16, p<0.001). Higher values of circumferential strain (lower deformation) and lower values of radial strain were found in segments with perfusion defects (β-estimate 2.76, p<0.001; and β-estimate -10.39, p<0.001, circumferential and radial strain, respectively).
While microvascular dysfunction was more prevalent in more hypertrophied segments, it also had a major presence in segments without hypertrophy. In this segmental analysis, we found an association between the presence of ischemia and tissue abnormalities, replacement fibrosis as well as impaired strain, independently of the segmental wall thickness.
微血管功能障碍是肥厚型心肌病（HCM）中一个常被忽视的特征。我们的目的是通过分析单个心肌节段，评估HCM患者微血管功能障碍、室壁厚度、组织特征和心肌变形之间的关联。
进行前瞻性评估，包括心脏磁共振成像以评估室壁厚度、T1和T2映射、细胞外容积、延迟钆增强（LGE）和应力灌注。根据美国心脏协会的16个节段对结果进行分层。
招募了75名患者（1200个节段），男性占63%，平均年龄54.6±14.8岁，最大室壁厚度为20.22±4.6mm。在424个（35%）存在灌注缺损的节段中，24%仅在内膜层有缺损，12%在内膜层和外膜层均有缺损。灌注缺损在肥厚节段中更常被检测到（64%）。在660个室壁厚度正常的节段中，19%存在灌注缺损。独立于室壁厚度，存在灌注缺损的节段T1值更高（β估计值30.28，p<0.001）、细胞外容积更高（β估计值1.50，p<0.001）、T2值更高（β估计值0.73，p<0.001）且延迟钆增强更频繁（优势比4.16，p<0.001）。在存在灌注缺损的节段中发现圆周应变值更高（变形更低），径向应变值更低（β估计值分别为2.76，p<0.001；和β估计值-10.39，p<0.001，圆周应变和径向应变）。
虽然微血管功能障碍在肥厚更严重的节段中更普遍，但在无肥厚节段中也很常见。在这项节段分析中，我们发现缺血的存在与组织异常、替代纤维化以及应变受损之间存在关联，且独立于节段室壁厚度。
