Wan Luqing, Tang Jianjun, Xiao Yanchao, Li Hui, Peng Zengjin, Xu Dan-Yan, Shen Li
Department of Internal Cardiovascular Medicine, Second Xiangya Hospital, Central South University, Changsha, China.
Front Cardiovasc Med. 2022 Sep 20;9:950437. doi: 10.3389/fcvm.2022.950437. eCollection 2022.
The hemodynamic changes of patients with aortic stenosis (AS) who underwent transcatheter valve replacement (TAVR) have not been completely investigated.
We enrolled 74 patients with AS who underwent TAVR and assessed cardiac function changes at 1 week post-operation by impedance cardiography (ICG) in a supine position at rest for more than 15 min. Of the 74 patients, 47 had preserved left ventricular ejection fraction (LVEF ≥ 50%; preserved-LVEF group) and 27 had reduced LVEF (LVEF <50%; reduced-LVEF group). TAVR improved the cardiac structure and function, as evidenced by the decrease in the left ventricular end-diastolic (LVED), left atrial diameter (LAD), and an increase in the LVEF. We observed a decrease in N-terminal pro-brain natriuretic peptide (NT-proBNP) level compared to that before treatment. Moreover, patients with reduced LVEF had a more significant reduction of NT-proBNP than those with preserved LVEF. Meanwhile, the blood pressure of patients had no significant differences pre- and post-operation. Based on ICG, there were no changes in the parameter of cardiac preload [thoracic fluid content (TFC)]. We observed an improvement in parameters of diastolic cardiac function [left ventricular ejection time (LVET) and pre-ejection period (PEP)]. And we detected converse results in parameters of heart systolic function [systolic time ratio (STR), cardiac output (CO), cardiac index (CI), stroke index (SI), and stroke volume (SV)] and cardiac afterload [stroke systemic vascular resistance (SSVR) and SSVR-index (SSVRI)]. In addition, TFC level was decreased in patients with thoracic volume overload after valve replacement. Subgroup analysis showed that the changes in those parameters were more noticeable in patients with reduced LVEF than that with preserved LVEF. Moreover, we observed no effects on parameters of heart systolic function and heart afterload in the LVEF ≥ 50% group before and after TAVR.
Our data revealed a beneficial effect of TAVR in diastolic function and preload as detected by the ICG. But the LV systolic function and cardiac afterload were not improved in patients with LVEF <50%. The result indicated that ICG could be used as an important technique to monitor the cardiac condition of patients after aortic valve replacement.
经导管瓣膜置换术（TAVR）治疗主动脉瓣狭窄（AS）患者的血流动力学变化尚未得到充分研究。
我们纳入了74例行TAVR的AS患者，并于术后1周通过阻抗心动图（ICG）在静息仰卧位超过15分钟时评估心脏功能变化。74例患者中，47例左心室射血分数保留（LVEF≥50%；LVEF保留组），27例LVEF降低（LVEF<50%；LVEF降低组）。TAVR改善了心脏结构和功能，表现为左心室舒张末期内径（LVED）、左心房直径（LAD）减小，LVEF增加。与治疗前相比，我们观察到N末端脑钠肽前体（NT-proBNP）水平降低。此外，LVEF降低的患者NT-proBNP降低比LVEF保留的患者更显著。同时，患者术前和术后血压无显著差异。基于ICG，心脏前负荷参数[胸腔液体含量（TFC）]无变化。我们观察到舒张期心脏功能参数[左心室射血时间（LVET）和射血前期（PEP）]有所改善。并且我们在心脏收缩功能参数[收缩时间比（STR）、心输出量（CO）、心脏指数（CI）、每搏指数（SI）和每搏量（SV）]和心脏后负荷[每搏全身血管阻力（SSVR）和SSVR指数（SSVRI）]方面检测到相反结果。此外，瓣膜置换术后胸腔容量超负荷患者的TFC水平降低。亚组分析显示，LVEF降低的患者这些参数的变化比LVEF保留的患者更明显。此外，我们观察到TAVR前后LVEF≥50%组的心脏收缩功能和心脏后负荷参数无变化。
我们的数据显示，ICG检测到TAVR对舒张功能和前负荷有有益影响。但LVEF<50%的患者左心室收缩功能和心脏后负荷未改善。结果表明，ICG可作为监测主动脉瓣置换术后患者心脏状况的重要技术。
