Department of Cardiology, Istanbul University Cerrahpasa Institute of Cardiology, Istanbul, Turkey.
Department of Radiology, Haseki Research and Education Hospital, Istanbul, Turkey.
Int J Cardiovasc Imaging. 2024 Nov;40(11):2417-2428. doi: 10.1007/s10554-024-03250-4. Epub 2024 Sep 30.
This study aimed to identify the phenotypic features contributing to the development of left ventricular outflow tract obstruction (LVOTO) in patients with hypertrophic cardiomyopathy (HCM) and to evaluate the genotype‒phenotype relationship. This cross-sectional study included 96 patients diagnosed with HCM (mean age: 56.9 ± 13.5 years, 32.3% female). The patients were divided into hypertrophic nonobstructive cardiomyopathy (HNCM; n = 60) and hypertrophic obstructive cardiomyopathy (HOCM; n = 36) groups. All patients underwent CMR. Patients (n = 77) who had previously provided formal approval underwent a genetic examination that included 18 genes. The anterior mitral leaflet (AML) length/LVOT diameter ratio, posterior mitral leaflet (PML) length/LVOT diameter ratio, and anterolateral papillary muscle (AL-PM) mobility were associated with LVOTO, independent of the basal IVS thickness, abnormal chordal attachment, and bifid PM. An AML length/LVOT diameter ratio of ≥ 2.30, a PML length/LVOT diameter ratio of ≥ 1.83, and an AL-PM mobility of ≥ 57.7% were predictors of LVOTO, with good sensitivity and specificity. Positive variants (VUS, LP, and P) were detected in 37.7% (29 of 77) of the patients who underwent genetic testing. The LP/P variant was detected in 20.8% (16 of 77) of patients. Three groups (variant-negative, VUS, and LP/P groups) had significant differences in the LVOT diameter (median 14, 12, and 10 mm, respectively; p = 0.021), AML length (mean 25.3, 26.5, and 27.5 mm, respectively; p = 0.029), AML length/LVOT diameter ratio (median 1.74, 2.33, and 2.85, respectively; p = 0.006), PML length/LVOT diameter ratio (median 1.29, 1.82, and 2.10, respectively; p = 0.045), and abnormal chordal attachment (6.3%, not observed, and 31.3%, respectively; p = 0.009). The AML length/LVOT diameter ratio, PML length/LVOT diameter ratio, and AL-PM mobility were associated with LVOTO. In addition, genetic testing results may provide information regarding the phenotypic expression of patients with HCM.
本研究旨在确定导致肥厚型心肌病（HCM）患者左心室流出道梗阻（LVOTO）发展的表型特征，并评估基因型-表型关系。这项横断面研究纳入了 96 名被诊断为 HCM 的患者（平均年龄：56.9±13.5 岁，32.3%为女性）。患者被分为肥厚型非梗阻性心肌病（HNCM；n=60）和肥厚型梗阻性心肌病（HOCM；n=36）组。所有患者均接受 CMR 检查。此前已提供正式批准的 77 名患者接受了包括 18 个基因的基因检测。前二尖瓣叶（AML）长度/LVOT 直径比、后二尖瓣叶（PML）长度/LVOT 直径比和前外侧乳头肌（AL-PM）活动性与 LVOTO 相关，与基底 IVS 厚度、异常腱索附着和分叉乳头肌无关。AML 长度/LVOT 直径比≥2.30、PML 长度/LVOT 直径比≥1.83 和 AL-PM 活动性≥57.7%是 LVOTO 的预测指标，具有良好的敏感性和特异性。在接受基因检测的 77 名患者中，检测到 37.7%（29/77）存在阳性变异（VUS、LP 和 P）。LP/P 变异在 20.8%（77 名患者中的 16 名）的患者中被发现。三个组（阴性变异、VUS 和 LP/P 组）在 LVOT 直径（中位数分别为 14、12 和 10mm；p=0.021）、AML 长度（均值分别为 25.3、26.5 和 27.5mm；p=0.029）、AML 长度/LVOT 直径比（中位数分别为 1.74、2.33 和 2.85；p=0.006）、PML 长度/LVOT 直径比（中位数分别为 1.29、1.82 和 2.10；p=0.045）和异常腱索附着（6.3%、未观察到和 31.3%；p=0.009）方面存在显著差异。AML 长度/LVOT 直径比、PML 长度/LVOT 直径比和 AL-PM 活动性与 LVOTO 相关。此外，基因检测结果可能提供有关 HCM 患者表型表达的信息。
