Li Tingyu, Ou Qiong, Zhou Xiaobing, Wei Xiaoyu, Cai Anping, Li Xiaodan, Ren Guanmin, Du Zhicheng, Hong Zuogeng, Cheng Yilu, Liu Hui
Department of Medical Imaging Center, Nanfang Hospital, Southern Medical University, Guangzhou, China.
Department of Radiology, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China.
Cardiovasc Diagn Ther. 2022 Aug;12(4):436-452. doi: 10.21037/cdt-22-38.
A comprehensive assessment of left ventricular (LV) remodeling and systolic function using contrast-enhanced cardiac magnetic resonance (CMR) imaging in patients with obstructive sleep apnea (OSA) has not yet been reported. This retrospective case-control study aimed to explore and assess the myocardial structure, function, and tissue characteristic changes of LV remodeling in patients with OSA using the CMR method.
Fifty-one selected participants 32 OSA and 19 non-OSA underwent overnight polysomnography and CMR examination using T1 mapping and feature tracking techniques. Twenty age- and sex-matched healthy controls were also enrolled for comparison between the groups.
Patients were grouped by apnea-hypopnea index (AHI): AHI <5 events/h as non-OSA group (n=19, 40.7±8.0 years), 5-30 events/h as mild-moderate OSA (n=13, 47.8±9.4 years), and >30 events/h as severe OSA (n=19, 39.0±10.0 years). The OSA group had a higher LV mass index (LVMI) to height than the non-OSA and healthy control groups (21.0±3.8 16.4±3.1 and 16.3±3.2 mL/m, P<0.001). Compared with healthy controls, OSA patients had lower global circumferential strain values, although the LV ejection fraction was preserved. Late gadolinium enhancement was not detected in all participants, whereas the extracellular volume fraction was lower in patients with OSA than in the non-OSA and healthy control groups (24.4%±1.9% 26.2%±2.5%, P=0.006 and 24.4%±1.9% 26.5%±2.3%, P=0.004, respectively). The indexed cellular volume (iCV) of the myocardium was significantly higher in subjects with mild-to-moderate and severe OSA than in those without OSA (14.2±2.3 and 15.8±3.1 11.6±2.4 mL/m, P<0.05). On multivariate linear regression analysis of patients with two different models, OSA severity remained significantly associated with increased LVMI (β=0.348, P=0.004 and β=0.233, P=0.048, respectively) and iCV (β=0.337, P=0.004 and β=0.231, P=0.047, respectively) after adjusting for clinical risk factors.
LVMI is elevated in OSA with a normal LV ejection fraction, mainly with cellular hypertrophy. Cellular hypertrophy without focal fibrosis in OSA may be our main finding.
尚未有关于使用对比增强心脏磁共振（CMR）成像对阻塞性睡眠呼吸暂停（OSA）患者进行左心室（LV）重构和收缩功能综合评估的报道。这项回顾性病例对照研究旨在使用CMR方法探索和评估OSA患者LV重构的心肌结构、功能和组织特征变化。
51名入选参与者（32名OSA患者和19名非OSA患者）接受了整夜多导睡眠监测，并使用T1映射和特征跟踪技术进行CMR检查。还纳入了20名年龄和性别匹配的健康对照者进行组间比较。
患者按呼吸暂停低通气指数（AHI）分组：AHI<5次/小时为非OSA组（n = 19，40.7±8.0岁），5 - 30次/小时为轻度至中度OSA组（n = 13，47.8±9.4岁），>30次/小时为重度OSA组（n = 19，39.0±10.0岁）。OSA组的左心室质量指数（LVMI）与身高之比高于非OSA组和健康对照组（分别为21.0±3.8、16.4±3.1和16.3±3.2 mL/m，P<0.001）。与健康对照组相比，OSA患者的整体圆周应变值较低，尽管左心室射血分数得以保留。所有参与者均未检测到延迟钆增强，而OSA患者的细胞外容积分数低于非OSA组和健康对照组（分别为24.4%±1.9%、26.2%±2.5%，P = 0.006；24.4%±1.9%、26.5%±2.3%，P = 0.004）。轻度至中度和重度OSA患者的心肌指数细胞容积（iCV）显著高于无OSA者（分别为14.2±2.3和15.8±3.1、11.6±2.·4 mL/m，P<0.05）。在两种不同模型的患者多变量线性回归分析中，调整临床危险因素后OSA严重程度仍与LVMI增加（β = 0.348，P = 0.004和β = 0.233，P = 0.048）和iCV增加（β = 0.337，P = 0.004和β = 0.231，P = 0.047）显著相关。
OSA患者左心室射血分数正常时LVMI升高，主要表现为细胞肥大。OSA中无局灶性纤维化的细胞肥大可能是我们的主要发现。
