Importance of the valve durability-life expectancy ratio in selection of a prosthetic aortic valve

Surgical aortic valve replacement (SAVR) has historically been the treatment of choice for patients with severe symptomatic aortic stenosis (AS). More recently, transcatheter aortic valve implantation (TAVI) has become a well-established alternative option for patients considered at high and intermediate preoperative surgical risk. TAVI provides effective relief of valve obstruction with excellent immediate and short-term outcomes. However, long-term (ie >10 years) durability of TAVI, relative to the known durability of surgical bioprosthetic valves,1 also needs to be considered. Indeed, there is, up to now, very few data addressing durability of TAVI beyond 5 years,2 which is particularly important in younger patients and those with few comorbidities who have many remaining expected years of life. Hence, long-term structural valve degeneration/deterioration (SVD) has become an important issue for patients and physicians making an informed decision between the choice of TAVI and SAVR bioprostheses. Two different mechanisms have been described for bioprosthetic valve failure. Structural valve deterioration/degeneration refers to acquired intrinsic changes of the prosthesis and includes leaflet calcification, leaflet tear, stent fracture or creep, and suture line disruption.3 4 Non-structural deterioration/degeneration includes prosthesis-patient mismatch (PPM), valve thrombosis, pannus ingrowth, paravalvular leakage (PVL) and endocarditis (figure 1). SVD due to progressive deterioration of valve leaflet tissue is the most common cause of surgical bioprostheses failure. A recent systematic review1 of 93 studies including 53 884 (age 53–92 years) patients with AS that focused on prognosis after SAVR with bioprosthetic valves showed that the median survival among those aged ≤65, 65–75, 75–85 and ≥85 years was 16, 12, 7 and 6 years, respectively. Importantly, the freedom from reoperation for valve dysfunction at 10, 15 and 20 years was 94%, 81.7% and 52%, respectively.1 Figure 1 Structural valve deterioration. Schematic drawing showing examples of structural and non-structural valve deterioration with a surgical or transcatheter bioprosthetic valve. The normal …