The influence of the valve expansion on the hemodynamic outcome in valve-in-valve transcatheter aortic valve replacement

Abstract Introduction Aortic valve replacement has become a standard therapy for patients with degenerated aortic valves. However, both surgical and transcatheter bioprostheses show progressive degeneration over the years, which can lead to stenosis, regurgitation or combined defects. These patients are potential candidates for valve-in-valve TAVR. Incomplete expansion of native TAVR prostheses is associated with higher postinterventional gradients and a higher rate of valve thrombosis and valve degeneration. Therefore, the optimization of the valve expansion is of high importance. However, so far limited data exist for the effects of the level of underexpansion of valve-in-valve prostheses. Purpose We hypothesized that an incomplete expansion of the prosthesis in valve-in-valve TAVR is associated with an unfavourable hemodynamic outcome. Proving that the postinterventional outcome depends on the optimal expansion might contribute to the optimization of valve-in-valve TAVR and the choice of the prosthesis model. Methods A retrospective monocentric study was performed. We included 190 patients who received a valve-in-valve TAVR between 2014 and 2024. The expansion level of the valve prostheses was measured in the angiographic recordings and correlated with the regular and complete expansion. The hemodynamic outcome was quantified using the postinterventional echocardiographic measurements and the VARC-criteria for aortic valve prostheses. Results We observed that an incomplete expansion of valve-in-valve TAVR in the waist area was associated with an unfavourable hemodynamic outcome in self-expanding valves. The expansion level in the waist area was correlated with the mean postinterventional gradient (Pearson’s r=-0.3849, p0.0001) and the maximal velocity (Pearson’s r=-0.3592, p0.0001). An underexpansion of 20% was associated with an increase of the mean postinterventional gradient of 9,9 mmHg and an increase of the maximal velocity of 0,7 m/s. No significant correlation was found in balloon-expanding valve prostheses. Moreover, underexpansion of the inflow or outflow did not change the haemodynamic outcome. Conclusion Periinterventional underexpansion of the waist area of aortic valve prostheses was associated with an unfavourable haemodynamic outcome of valve-in-valve TAVR procedures in self-expandable prostheses.