Patient–prosthesis mismatch and long-term outcome following aortic valve replacement

Avoiding any prosthesis–patient mismatch, defined as Effective Orifice Area (EOA) < 0.85 cm2/m2 [1], the anticipation of a valve prosthesis, which will outlive the patient’s prognosis after assessing all competing risks, and the extent of the patient’s compliance, relating to the postoperative anticoagulation strategy, are 3 important directing criteria considering the type and size of the chosen aortic valve prosthesis for implantation. The European Association of Cardiothoracic Surgery (EACTS)/European Association of Cardiology (ESC) guidelines 2021 have fortified this patient-centred evaluation approach as well as a life-long comprehensive individualized valve-intervention strategy [2]. So, all surgical-, minimal access-, percutaneous options during first- and anticipated consecutive redo procedures should be on the table when the patient is discussed in the Valvular Heart Team for the first time. Obviously, judiciously trade-offs are sometimes mandatory in the real-world of valve-diseased patients. Whereas the implantation of a 19-mm biological prosthesis could provide a satisfactory anticipated EOA in a specific subset of low Body Surface Area (BSA) patients, in others it could, theoretically, result in a patient–prosthesis mismatch, which could prove clinically relevant. Various studies have reported that patient–prosthesis mismatch is a frequent and relevant haemodynamic complication of surgical aortic valve replacement. The main reason for patient–prosthesis mismatch are small surgical valves (inner diameters ≤20 mm), and this is a known risk factor for high post procedural transvalvular gradients which in turn might affect mid-term outcome [3–7]. Besides redo surgery, transcatheter valve-in-valve implantation is an acceptable treatment option for moderate to high risk patients or even elderly (>80 years) patients with a degenerated aortic valve bioprosthesis [8]. Nowadays, even high-pressure balloon aortic valvuloplasty has been reported to improve the hydrodynamics after a transcatheter valve-in-valve procedure in a small sized surgical prothesis [9]. So, our therapeutic options are expanding. This current trend towards bioprostheses is being encouraged by the industry with recent developments of bioprosthetic valves (Inspiris Resilia aortic valve®, Edwards Lifesciences LLC, Irvine, USA) with features designed for potential future valve-in-valve procedures such as fluoroscopically visible size markers and an expandable cobalt chromium alloy band. With this trend towards bioprostheses for surgical aortic valve replacement, it is expected that the number of transcatheter Valve in Valve (ViV) procedures even in small surgical valves will increase [3]. The idea of a smaller inner diameter and poor haemodynamic values correlating with a negative outcome is recurrent and seems to be implied in many studies [10], even though complete follow-up data for these patients are lacking. In their study, Okamura et a [11]. try to find out what the long-term outcomes of aortic valve replacement using a 19-mm bioprosthesis are? They analysed a total of 132 consecutive patients who underwent surgical aortic valve replacement using a 19-mm bioprosthesis at their institution between the time frame of 2008 and 2012. They could show during the median follow-up period of 7.7 years that the overall 5- and 10-year survival rates were 79.4% and 52.9%, respectively. The 5- and 10-year freedom from major adverse valve-related events rates were 89.6% and 74.2%, respectively, and neither moderate nor severe prosthesis–patient mismatch was associated with late mortality, major adverse valve-related events, or heart failure. These data lead to the conclusion that surgical aortic valve replacement using the 19-mm bioprosthesis was associated with satisfactory long-term clinical and haemodynamic outcomes. While their results may be acceptable, surgical aortic valve replacement with a larger valve show better long-term results and is considered the preferred treatment strategy by surgeons [11]. The larger valves do not only offer better outcomes, but they also provide a larger spectrum of treatment alternatives in cases of degenerations. Surgeons are encouraged to prospectively calculate the predicted indexed effective orifice area of the prosthesis and the patient’s body surface area and hence plan their surgical procedure accordingly; either with an aortic root enlargement (Nikcs-Nunez or Manougian technique), which can be performed without additional operation risk [12] or with a rapid deployment surgical valve to avoid patient–prosthesis mismatch, taking into account that a life-long individualized valve-intervention strategy is becoming the benchmark.