Vogl Brennan J, Chavez-Ponce Alejandra, Wentworth Adam, Erie Eric, Yadav Pradeep, Thourani Vinod H, Dasi Lakshmi Prasad, Lindman Brian, Alkhouli Mohamad, Hatoum Hoda
Biomedical Engineering Department, Michigan Technological University, Houghton, Michigan, USA.
Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota, USA.
Struct Heart. 2023 Nov 13;8(1):100230. doi: 10.1016/j.shj.2023.100230. eCollection 2024 Jan.
The cause for the association between increased cardiovascular mortality rates and lower blood pressure (BP) after aortic valve replacement (AVR) is unclear. This study aims to assess how the epicardial coronary flow (ECF) after AVR varies as BP levels are changed in the presence of a right coronary lesion.
The hemodynamics of a 3D printed aortic root model with a SAPIEN 3 26 deployed were evaluated in an left heart simulator under a range of varying systolic blood pressure (SBP) and diastolic blood pressure (DBP). ECF and the flow ratio index were calculated. Flow index value <0.8 was considered a threshold for ischemia.
As SBP decreased, the average ECF decreased below the physiological coronary minimum at 120 mmHg. As DBP decreased, the average ECF was still maintained above the physiological minimum. The flow ratio index was >0.9 for SBP ≥130 mmHg. However, at an SBP of 120 mmHg, the flow ratio was 0.63 ( ≤ 0.0055). With decreasing DBP, no BP condition yielded a flow ratio index that was less than 0.91.
Reducing BP to the current recommended levels assigned for the general population after AVR in the presence of coronary artery disease may require reconsideration of levels and treatment priority. Additional studies are needed to fully understand the changes in ECF dynamics after AVR in the presence and absence of coronary artery disease.
主动脉瓣置换术（AVR）后心血管死亡率增加与血压（BP）降低之间的关联原因尚不清楚。本研究旨在评估在存在右冠状动脉病变的情况下，AVR后心外膜冠状动脉血流（ECF）如何随BP水平变化而变化。
在左心模拟器中，对植入SAPIEN 3 26瓣膜的3D打印主动脉根部模型在一系列不同的收缩压（SBP）和舒张压（DBP）下的血流动力学进行评估。计算ECF和血流比指数。血流指数值<0.8被认为是缺血阈值。
随着SBP降低，平均ECF在120 mmHg时降至生理冠状动脉最小值以下。随着DBP降低，平均ECF仍维持在生理最小值以上。当SBP≥130 mmHg时，血流比指数>0.9。然而，在SBP为120 mmHg时，血流比为0.63（≤0.0055）。随着DBP降低，没有任何BP条件下的血流比指数小于0.91。
在存在冠状动脉疾病的情况下，将AVR后BP降至目前为普通人群推荐的水平可能需要重新考虑水平和治疗优先级。需要进一步研究以充分了解在存在和不存在冠状动脉疾病的情况下AVR后ECF动力学的变化。
