Increased Gradients After Aortic Valve Replacement With the Perceval Valve: The Role of Oversizing

Significant underexpansion or distortion of valved stents may be associated with altered leaflet function, leading to increased transprosthetic gradients and, possibly, early structural degeneration. We investigated the relationship between a computed tomography measure of the degree of oversizing and the early hemodynamic and clinical outcomes in patients undergoing aortic valve replacement with the Perceval sutureless aortic valve (LivaNova, Saluggia, Italy).

The degree of oversizing of the implanted prosthesis was calculated as the ratio between the patients' aortic annulus cross-sectional area and the ex vivo cross-sectional area of the implanted prosthesis in 151 Perceval patients who underwent preoperative cardiac computed tomography. This value was then entered in a multivariate analysis to ascertain its role as a predictor of increased postoperative gradient.

The operative mortality was 1.3%. Procedural success, defined as having a normally functioning valve in the proper anatomical location, was achieved in 150 patients (99.3%). The mean transprosthetic gradient was 13.4 ± 5.0 mm Hg, and 23 patients (15.2%) showed a gradient of 20 mm Hg or more at discharge or at the 1-month follow-up. The degree of oversizing of the implanted prosthesis was the most important predictor of increased postoperative gradient (odds ratio, 1.264; 95% confidence interval, 1.147 to 1.394; p < 0.0001). Interestingly, other relevant factors (patients' body surface area, prosthesis size) were not associated with increased gradients.

Our study demonstrates that excessive oversizing should be avoided in Perceval patients and suggests that a different sizing algorithm, possibly based on cardiac computed tomography, should be developed. Further studies are needed to optimize the sizing strategy for the Perceval sutureless valve.