Patient Prosthesis Mismatch After SAVR and TAVR

Abstract

Patient-prosthesis mismatch (PPM) remains one out of many factors to be considered during decision-making for the treatment of aortic valve pathologies. The idea of adequate sizing of a prosthetic heart valve was established by Rahimtoola already in 1978. In this article, the author described the phenomenon that the orifice area of a prosthetic heart valve may be too small for the individual patient. PPM is assessed by measurement or projection of the prosthetic effective orifice area indexed to body surface area (iEOA), while it is recommended to use different cut point values for non-obese and obese patients for the categorization of moderate and severe PPM. Several factors influence the accuracy of both the projected and the measured iEOA for PPM assessment, which leads to a certain number of false assignments to the PPM or no PPM group. Despite divergent findings on the impact of PPM on clinical outcomes, there is consensus that PPM should be avoided to prevent sequelae of increased prosthetic gradients after aortic valve replacement. To prevent PPM, it is required to anticipate the iEOA of the prosthesis prior to the procedure. The use of adequate reference tables, derived from echocardiographically measured mean effective orifice area (EOA) values from preferably large numbers of patients, is most appropriate to predict the iEOA. Such tables should be used also for transcatheter heart valves in the future. During the decision-making process, all available options should be taken into account for the individual patient. If the predicted size and type of a surgical prosthesis cannot be implanted, additional surgical procedures, such as annular enlargement with the Manougian technique, or alternative procedures, such as transcatheter aortic valve implantation (TAVI) can prevent PPM. PPM prevention for TAVI patients is a new field of interest and includes anticipation of the iEOA, prosthesis selection, and procedural strategies.

Early and mid-term outcome of patients with low-flow–low-gradient aortic stenosis treated with newer-generation transcatheter aortic valves

“…Looking at post-procedural mean transvalvular gradient, THVs performed better than surgical aortic valve prostheses. This superiority of THVs is well-known, in particular with the use of supra-annular devices (60.8% in our series) ( 31 – 33 ). This is a point in favor of TAVR when discussing the best therapeutic option in the case of LFLG AS, as the more complete is the relief of afterload mismatch, the higher is the probability of LV recovery ( 34 , 35 ).…”

Hemodynamic Performance of Two Current-Generation Transcatheter Heart Valve Prostheses in Severely Calcified Aortic Valve Stenosis

“…It seems that PPM is associated with an impaired outcome in patients with reduced ejection fraction [ 52 ]. This has led some experts to prioritizing self-expanding THV in this patient group [ 53 ].…”

Comparisons of different new-generation transcatheter aortic valve implantation devices for patients with severe aortic stenosis: a systematic review and network meta-analysis

“…In addition, the present study showed lower frequency of PPM in SEVs than in Lotus and Sapien 3. However, the results should be interpreted with caution because the severity of PPM, which was assessed by transthoracic echocardiogram derived indexed effective orifice area (EOA), was more often overestimated in Sapien 3 compared with SEVs due to the pressure recovery phenomenon 101 , 102 . Fukui et al demonstrated that using computed tomography-derived EOA instead of transthoracic echocardiogram derived EOA changed the frequency of PPM observed with SEVs and Sapien 3 from 11.1% versus 24.6% ( P = 0.002) to 2.3% versus 4.2% ( P = 0.399) 35 .…”