Clinical and Technical Challenges of Prosthesis–Patient Mismatch After Transcatheter Aortic Valve Implantation

Abstract

Prosthesis–patient mismatch (PPM) is present when the effective area of a prosthetic valve inserted into a patient is inferior to that of a normal human valve; the hemodynamic consequence of a valve too small compared with the size of the patient's body is the generation of higher than expected transprosthetic gradients. Despite evidence of increased risk of short- and long-term mortality and of structural valve degeneration in patients with PPM after surgical aortic valve replacement, its clinical impact in patients subject to transcatheter aortic valve implantation (TAVI) is yet unclear. We aim to review and update on the definition and incidence of PPM after TAVI, and its prognostic implications in the overall population and in higher-risk subgroups, such as small aortic annuli or valve-in-valve procedures. Last, we will focus on the armamentarium available in order to reduce risk of PPM when planning a TAVI procedure.

Prosthesis‐patient mismatch after transcatheter implantation of contemporary balloon‐expandable and self‐expandable valves in small aortic annuli

“…10 Reasons behind the described selective prognostic impact of severe PPM might include derivation of echocardiographic mean gradients from transaortic velocity, and are being addressed. [22][23][24] Notably, indexed EOA did not differ among patients with severe PPM according to the type of valve implanted, and it was actually lower in patients without severe PPM with BEV than with SEV and with IAV than with SAV. Ascertainment in additional studies is urged to be able to attribute such differences to mere measurement fallacies or to real differences in prognostic relevance.…”

“…On the other hand, severe PPM did predict mortality in the CoreValve US High‐Risk trial, 9 even though this was not confirmed in a recent analysis of 47,620 patients from the Transcatheter Valve Therapy registry 10 . Reasons behind the described selective prognostic impact of severe PPM might include derivation of echocardiographic mean gradients from transaortic velocity, and are being addressed 22–24 . Notably, indexed EOA did not differ among patients with severe PPM according to the type of valve implanted, and it was actually lower in patients without severe PPM with BEV than with SEV and with IAV than with SAV.…”

The Konno procedure to treat ­prosthesis-patient mismatch and complex left ventricular outflow tract obstruction in adult patients

“…In addition, PPM may also preclude regression of left ventricular hypertrophy [13,14]. More recently, some reports about PPM following transcatheter aortic valve implantation and surgical implantation of sutureless (rapid-deployment) valves, that have a similar design to transcatheter devices have been published as well [4,7,[12][13][14][15][16]. In the early postoperative period, PPM may have a particular negative impact on outcome because it may affect patients with impaired left ventricular function prior to surgery because the preoperatively damaged left ventricle is particularly vulnerable when a residual gradient increases the hemodynamic burden.…”