Challenges in transcatheter valve treatment: aortic regurgitation after transcatheter aortic valve implantation.

Paravalvular aortic regurgitation (AR) has a negative impact on the prognosis following transcatheter aortic valve implantation (TAVI). As transcatheter heart valves (THV) are implanted in a sutureless fashion using oversizing to anchor the prosthesis stent frame at the level of the virtual aortic annulus, incomplete stent frame expansion due to heavily calcified cusps, suboptimal placement of the prosthesis, and/or annulus-prosthesis size mismatch due to malsizing can contribute to paravalvular AR with increased mortality in patients with more than mild paravalvular AR. Echocardiography is essential to differentiate between transvalvular and paravalvular AR and to elucidate further the aetiology of AR during the procedure. However, since echocardiographic quantification of AR in TAVI patients remains challenging especially in the implantation situation, a multimodal approach for the evaluation of AR with use of haemodynamic measurements and imaging modalities is imperative to quantify the severity of AR precisely immediately after valve implantation. Thus, patients who will benefit from corrective measures such as post-dilation or valve-in-valve implantation can be identified. In these patients, every measure has to be taken to reduce paravalvular aortic regurgitation in order to improve outcome.