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Aortic blood flow patterns are closely linked to the morphology and function of the left ventricle, aortic valve and aorta. These flow patterns demonstrate the exceptional adaptability of the cardiovascular system to maintain blood circulation under a broad range of haemodynamic workloads and can be altered in various pathophysiological states. For instance, normal ascending aortic systolic flow is predominantly laminar, whereas abnormal aortic systolic flow is associated with increased eccentricity, vorticity and flow reversal. These flow abnormalities result in reduced aortic conduit function and increased energy loss in the cardiovascular system. Emerging evidence details the association of these flow patterns with loss of aortic compliance, which leads to adverse left ventricular remodelling, poor tissue perfusion, and an increased risk of morbidity and death. In this Perspective article, we review the evidence for the link between aortic flow-related abnormalities and cardiovascular disease and how these changes in aortic flow patterns are emerging as a therapeutic target for aortic valve intervention in first-in-human studies., (© 2023. Springer Nature Limited.)

Importance: Transcatheter aortic valve replacement (TAVR) is established for selected patients with severe aortic stenosis. However, limitations such as suboptimal deployment, conduction disturbances, and paravalvular leak occur., Objective: To evaluate if a mechanically expanded valve (MEV) is noninferior to an approved self-expanding valve (SEV) in high-risk patients with aortic stenosis undergoing TAVR., Design, Setting, and Participants: The REPRISE III trial was conducted in 912 patients with high or extreme risk and severe, symptomatic aortic stenosis at 55 centers in North America, Europe, and Australia between September 22, 2014, and December 24, 2015, with final follow-up on March 8, 2017., Interventions: Participants were randomized in a 2:1 ratio to receive either an MEV (n = 607) or an SEV (n = 305)., Main Outcomes and Measures: The primary safety end point was the 30-day composite of all-cause mortality, stroke, life-threatening or major bleeding, stage 2/3 acute kidney injury, and major vascular complications tested for noninferiority (margin, 10.5%). The primary effectiveness end point was the 1-year composite of all-cause mortality, disabling stroke, and moderate or greater paravalvular leak tested for noninferiority (margin, 9.5%). If noninferiority criteria were met, the secondary end point of 1-year moderate or greater paravalvular leak was tested for superiority in the full analysis data set., Results: Among 912 randomized patients (mean age, 82.8 [SD, 7.3] years; 463 [51%] women; predicted risk of mortality, 6.8%), 874 (96%) were evaluable at 1 year. The primary safety composite end point at 30 days occurred in 20.3% of MEV patients and 17.2% of SEV patients (difference, 3.1%; Farrington-Manning 97.5% CI, -∞ to 8.3%; P = .003 for noninferiority). At 1 year, the primary effectiveness composite end point occurred in 15.4% with the MEV and 25.5% with the SEV (difference, -10.1%; Farrington-Manning 97.5% CI, -∞ to -4.4%; P<.001 for noninferiority). The 1-year rates of moderate or severe paravalvular leak were 0.9% for the MEV and 6.8% for the SEV (difference, -6.1%; 95% CI, -9.6% to -2.6%; P < .001). The superiority analysis for primary effectiveness was statistically significant (difference, -10.2%; 95% CI, -16.3% to -4.0%; P < .001). The MEV had higher rates of new pacemaker implants (35.5% vs 19.6%; P < .001) and valve thrombosis (1.5% vs 0%) but lower rates of repeat procedures (0.2% vs 2.0%), valve-in-valve deployments (0% vs 3.7%), and valve malpositioning (0% vs 2.7%)., Conclusions and Relevance: Among high-risk patients with aortic stenosis, use of the MEV compared with the SEV did not result in inferior outcomes for the primary safety end point or the primary effectiveness end point. These findings suggest that the MEV may be a useful addition for TAVR in high-risk patients., Trial Registration: ClinicalTrials.gov Identifier: NCT02202434.

Objectives: This study aimed to develop a procedure simulation platform for in vitro transcatheter aortic valve replacement (TAVR) using patient-specific 3-dimensional (3D) printed tissue-mimicking phantoms. We investigated the feasibility of using these 3D printed phantoms to quantitatively predict the occurrence, severity, and location of any degree of post-TAVR paravalvular leaks (PVL)., Background: We have previously shown that metamaterial 3D printing technique can be used to create patient-specific phantoms that mimic the mechanical properties of biological tissue. This may have applications in procedural planning for cardiovascular interventions., Methods: This retrospective study looked at 18 patients who underwent TAVR. Patient-specific aortic root phantoms were created using the tissue-mimicking 3D printing technique using pre-TAVR computed tomography. The CoreValve (self-expanding valve) prostheses were deployed in the phantoms to simulate the TAVR procedure, from which post-TAVR aortic root strain was quantified in vitro. A novel index, the annular bulge index, was measured to assess the post-TAVR annular strain unevenness in the phantoms. We tested the comparative predictive value of the bulge index and other known predictors of post-TAVR PVL., Results: The maximum annular bulge index was significantly different among patient subgroups that had no PVL, trace-to-mild PVL, and moderate-to-severe PVL (p = 0.001). Compared with other known PVL predictors, bulge index was the only significant predictor of moderate-severe PVL (area under the curve = 95%; p < 0.0001). Also, in 12 patients with post-TAVR PVL, the annular bulge index predicted the major PVL location in 9 patients (accuracy = 75%)., Conclusions: In this proof-of-concept study, we have demonstrated the feasibility of using 3D printed tissue-mimicking phantoms to quantitatively assess the post-TAVR aortic root strain in vitro. A novel indicator of the post-TAVR annular strain unevenness, the annular bulge index, outperformed the other established variables and achieved a high level of accuracy in predicting post-TAVR PVL, in terms of its occurrence, severity, and location., (Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)