Goode Dylan, Scotten Lawrence, Siegel Rolland, Blundon David, Dutton James, Mohammadi Hadi
The Heart Valve Performance Laboratory, School of Engineering, Faculty of Applied Science, University of British Columbia, Kelowna, BC, Canada.
Independent Consultant, Victoria, BC, Canada.
J Biomech. 2025 May;184:112647. doi: 10.1016/j.jbiomech.2025.112647. Epub 2025 Mar 25.
Valvular heart disease, particularly aortic valve (AV) calcification, remains a significant issue, with AV replacement surgeries among the most common procedures. Current surgical options include mechanical heart valves (MHVs) and bioprosthetic valves, each with inherent limitations. MHVs offer long-term durability but require lifelong anticoagulation therapy, while bioprosthetic valves provide superior hemodynamics but lack durability. The MHV's non-physiological flow patterns through the hinges and spikes in regional backflow velocity (RBV) during closure may contribute to the need for anticoagulation. This study evaluates two emerging MHVs, the iValve and Triflo, alongside established prosthetic valves. The iValve, featuring a novel bileaflet design, and the Triflo, a trileaflet valve, aim to overcome current MHV limitations. In vitro testing used a pulse duplicator system to assess projected open area (POA), volumetric flow rate, regurgitant volumes, and trans-AV pressure relative to mean pressure (pressure ratio). POA and volumetric flow rates were used to calculate flow velocity and RBV. Results indicate that the iValve and Triflo achieved comparable pressure ratios and significantly lower mean and peak RBV values than traditional MHVs like the SJM and On-X. This suggests improved flow dynamics and reduced shear stress on blood components, potentially minimizing anticoagulation requirements. The iValve prototypes showed regurgitant volumes comparable to conventional MHVs, while the Triflo performed similarly to the control valve. These findings underscore the potential of next-generation MHVs to combine durability, hemodynamic performance, and reduced thrombogenic risk closer to the native valve.
心脏瓣膜病，尤其是主动脉瓣钙化，仍然是一个重大问题，主动脉瓣置换手术是最常见的手术之一。目前的手术选择包括机械心脏瓣膜（MHV）和生物人工瓣膜，每种都有其固有的局限性。机械心脏瓣膜具有长期耐用性，但需要终身抗凝治疗，而生物人工瓣膜具有更好的血流动力学性能，但缺乏耐用性。机械心脏瓣膜在关闭过程中通过铰链的非生理性血流模式以及局部反流速度（RBV）中的尖峰可能导致需要抗凝。本研究评估了两种新型机械心脏瓣膜iValve和Triflo以及已有的人工瓣膜。iValve具有新颖的双叶设计，Triflo是三叶瓣膜，旨在克服当前机械心脏瓣膜的局限性。体外测试使用脉动复制系统来评估预计开口面积（POA）、容积流量、反流容积以及相对于平均压力的跨主动脉瓣压力（压力比）。POA和容积流量用于计算流速和RBV。结果表明，iValve和Triflo实现了可比的压力比，并且与SJM和On-X等传统机械心脏瓣膜相比，平均和峰值RBV值显著更低。这表明血流动力学得到改善，血液成分上的剪切应力降低，可能将抗凝需求降至最低。iValve原型的反流容积与传统机械心脏瓣膜相当，而Triflo的表现与对照瓣膜相似。这些发现强调了下一代机械心脏瓣膜在结合耐用性、血流动力学性能以及降低血栓形成风险方面接近天然瓣膜的潜力。
