Kong Huihui, Cao Jiaxin, Tian Jinfan, Yong Jingwen, An Jing, Zhang Lijun, Song Xiantao, He Yi
Department of Radiology, Beijing Friendship Hospital, Capital Medical University, Beijing, China.
Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China.
Quant Imaging Med Surg. 2023 Oct 1;13(10):7281-7293. doi: 10.21037/qims-23-47. Epub 2023 Sep 11.
Coronary microvascular dysfunction (CMD) has been suggested to be one of the pathologic mechanisms contributing to heart failure with preserved left ventricular ejection fraction (LVEF) and left ventricular (LV) diastolic dysfunction. We therefore aimed to evaluate LV diastolic function in patients with CMD using cardiovascular magnetic resonance feature tracking (CMR-FT).
We prospectively enrolled 115 patients referred to cardiology clinics for chest pain assessment who subsequently underwent coronary computed tomography angiogram and stress perfusion CMR. CMD was defined as the presence of subendocardial inducible ischemia detected through visual assessment. LV diastolic function was evaluated using CMR-derived volume-time curves and CMR-FT parameters. The former included early peak filling rate (PFR) and time to PFR; the latter included LV global/regional peak longitudinal diastolic strain rate (LDSR), circumferential diastolic strain rate (CDSR), and radial diastolic strain rate (RDSR).
A total of 92 patients with 1,312 segments were eventually included. Of these, 19 patients were classified as non-CMD (48.8±11.2 years; 63.2% male) and 73 as with CMD (52.3±11.9 years; 54.8% male). The LVEFs were similar and preserved in both groups (P=0.266). At the per-patient level, no differences were observed in PFR, time to PFR, or LV global diastolic strain rates between the two groups. At the per-segment level, 51% (665/1,312) of the myocardial segments were classified as CMD, whereas 49% (647/1,312) were classified as non-CMD. CMD segments showed significantly lower regional CDSR (P=0.019) and RDSR (P=0.006) compared with non-CMD segments.
Despite normal LV ejection fraction in CMD patients, decreased LV diastolic function in CMD myocardial segments indicates early diastolic impairment.
冠状动脉微血管功能障碍（CMD）被认为是导致左心室射血分数（LVEF）保留的心力衰竭和左心室（LV）舒张功能障碍的病理机制之一。因此，我们旨在使用心血管磁共振特征追踪（CMR-FT）评估CMD患者的左心室舒张功能。
我们前瞻性纳入了115名因胸痛评估而转诊至心脏病诊所的患者，这些患者随后接受了冠状动脉计算机断层扫描血管造影和负荷灌注CMR。CMD被定义为通过视觉评估检测到心内膜下诱导性缺血。使用CMR得出的容积-时间曲线和CMR-FT参数评估左心室舒张功能。前者包括早期峰值充盈率（PFR）和达到PFR的时间；后者包括左心室整体/区域纵向舒张峰值应变率（LDSR）、圆周舒张应变率（CDSR）和径向舒张应变率（RDSR）。
最终共纳入92名患者的1312个节段。其中，19名患者被分类为非CMD（48.8±11.2岁；63.2%为男性），73名患者被分类为CMD（52.3±11.9岁；54.8%为男性）。两组的LVEF相似且均保留（P=0.266）。在患者层面，两组之间在PFR、达到PFR的时间或左心室整体舒张应变率方面未观察到差异。在节段层面，51%（665/1312）的心肌节段被分类为CMD，而49%（647/1312）被分类为非CMD。与非CMD节段相比，CMD节段显示出明显更低的区域CDSR（P=0.019）和RDSR（P=0.006）。
尽管CMD患者的左心室射血分数正常，但CMD心肌节段的左心室舒张功能下降表明存在早期舒张功能损害。
