Safety and Efficacy of TAVR With a Pressure Sensor and Pacing Guidewire: SAFE-TAVI Trial.

BACKGROUND: The SavvyWire (OpSens Inc) is a 0.035-inch preshaped guidewire with dedicated pacing properties and a distal pressure sensor allowing for continuous hemodynamic pressure monitoring. OBJECTIVES: This study sought to determine the efficacy and safety of the guidewire during transcatheter aortic valve replacement (TAVR) procedures. METHODS: This prospective, multicenter clinical study included patients with severe aortic stenosis undergoing TAVR in 8 European centers. The primary efficacy endpoint was defined as effective left ventricular rapid pacing runs with the guidewire translating into a significant systemic pressure drop (below 60 mm Hg). The safety outcome included the absence of major procedural complications related to the guidewire. RESULTS: A total of 121 patients (mean age: 82.2 ± 5.9 years, 50% women) were included in the study, and 119 (98.3%) patients were finally treated with the study device. A balloon-expandable valve was implanted in 45 (37.8%) patients. Predilatation and postdilatation were performed in 89 (74.8%) and 14 (11.8%) patients, respectively. The primary efficacy endpoint was achieved in 116 (98.3%) patients, and the mean aortic systolic arterial pressure achieved during rapid pacing was 46.6 ± 11.3 mm Hg. Hemodynamic assessment with the use of the OptoMonitor 3 (OpSens Inc) without additional catheter exchange was achieved in 117 (99.2%) patients. The safety endpoint was achieved in 117 (99.2%) patients. No procedural mortality, stroke, or ventricular perforation was reported. CONCLUSIONS: The use of the guidewire during TAVR procedures appeared to be efficacious and safe. This device could help minimize interventions during the procedure and improve the clinical decision making after transcatheter heart valve deployment. (SavvyWire Efficacy and Safety in Transcatheter Aortic Valve Implantation Procedures [SAFE-TAVI]; NCT05492383).

Cell Seeding on UV-C-Treated 3D Polymeric Templates Allows for Cost-Effective Production of Small-Caliber Tissue-Engineered Blood Vessels.

There is a strong clinical need to develop small-caliber tissue-engineered blood vessels for arterial bypass surgeries. Such substitutes can be engineered using the self-assembly approach in which cells produce their own extracellular matrix (ECM), creating a robust vessel without exogenous material. However, this approach is currently limited to the production of flat sheets that need to be further rolled into the final desired tubular shape. In this study, human fibroblasts and smooth muscle cells were seeded directly on UV-C-treated cylindrical polyethylene terephthalate glycol-modified (PETG) mandrels of 4.8 mm diameter. UV-C treatment induced surface modification, confirmed by Fourier-transform infrared spectroscopy (FTIR) analysis, was necessary to ensure proper cellular attachment and optimized ECM secretion/assembly. This novel approach generated solid tubular conduits with high level of cohesion between concentric cellular layers and enhanced cell-driven circumferential alignment that can be manipulated after 21 days of culture. This simple and cost-effective mandrel-seeded approach also allowed for endothelialization of the construct and the production of perfusable trilayered tissue-engineered blood vessels with a closed lumen. This study lays the foundation for a broad field of possible applications enabling custom-made reconstructed tissues of specialized shapes using a surface treated 3D structure as a template for tissue engineering.

Tissue-Engineered Tubular Heart Valves Combining a Novel Precontraction Phase with the Self-Assembly Method.

Recently, the tubular shape has been suggested as an effective geometry for tissue-engineered heart valves, allowing easy fabrication, fast implantation, and a minimal crimped footprint from a transcatheter delivery perspective. This simple design is well suited for the self-assembly method, with which the only support for the cells is the extracellular matrix they produce, allowing the tissue to be completely free from exogenous materials during its entire fabrication process. Tubular constructs were produced by rolling self-assembled human fibroblast sheets on plastic mandrels. After maturation, the tubes were transferred onto smaller diameter mandrels and allowed to contract freely. This precontraction phase thickened the tissue and prevented further contraction, while improving fusion between the self-assembled layers and aligning the cells circumferentially. When mounted in a pulsed-flow bioreactor, the valves showed good functionality with large leaflets coaptation and opening area. Although physiological aortic flow conditions were not reached, the leaflets could withstand a 1 Hz pulsed flow with a 300 mL/s peak flow rate and a 70 mmHg peak transvalvular pressure. This study shows that the self-assembly method, which has already proven its potential for the production of small diameter vascular grafts, could also be used to achieve functional tubular heart valves.