Original Title: Regression of Paravalvular Aortic Regurgitation and Remodeling of Self-Expanding Transcatheter Aortic Valve. An Observation From the CoreValve U.S. Pivotal Trial. Reference: Jae K. Oh et al. J Am Coll Cardiol Img. 2015, online first.

The aim of this study was to describe the natural evolution and the clinical significance of paravalvular aortic insufficiency after valve replacement with self-expanding CoreValve.

Regression of paravalvular aortic regurgitation over time has been described but the mechanism behind this phenomenon remains unclear.
The study analyzed all patients with severe aortic stenosis included in the multicenter study CoreValve U.S. Pivotal Trial (Safety and Efficacy Study of the Medtronic CoreValve System in the Treatment of Symptomatic Severe Aortic Stenosis in High Risk and Very High Risk Subjects Who Need Aortic Valve Replacement) at one year clinical and serial echocardiographic follow up. The self-expanding valve was implanted in 634 patients aged 82.7 ± 8.4 years.

When comparing echocardiogram measures prior to hospital discharge against measures at one month after procedure, a significant improvement was observed in AV mean pressure gradient and effective orifice area (2.08 ± 0.45 m/s vs. 1.99 ± 0.46 m/s; p < 0.0001, 9.7 ± 4.4 mm Hg vs. 8.9 ± 4.6 mm Hg; p < 0.0001 and 1.78 ± 0.51 cm2 vs. 1.85 ± 0.58 cm2; p = 0.03, respectively). This improvement of all parameters continued after one year follow up.

At discharge, 36 patients of this series presented moderate to severe paravalvular aortic regurgitation, and 30 of them (83%) improved at least one grade (from severe to moderate) after one year.

Conclusion
After one year follow up, there was significant improvement of hemodynamic parameters and regression of paravalvular regurgitation, compared to observations right after discharge.
These changed may be associated to the valve continuous expansion and remodeling, because of the nitinol frame.