INTRODUCTION
Patient-prosthesis mismatch (PPM) represents the mismatch between the
prosthetic valve’s effective orifice area (EOA) and the patient’s
haemodynamic requirements.(1) Given the large heterogeneity of the
patient population, PPM is most commonly presented as EOA divided by the
patient’s body surface area (BSA), resulting in indexed EOA (iEOA)
values. An iEOA between 0,85 cm2/m2and 0,65 cm2/m2 is considered
moderate PPM, while an iEOA < 0,65
cm2/m2 is considered severe PPM.(2)
Furthermore, it can be calculated as measured or predicted. If it is
measured, it is usually done via a transthoracic echocardiography exam
before hospital discharge. However, this echocardiographer-dependent
method is subject to diversity in findings. Also, it is flow dependent
and may lead to overestimating PPM in a heart with a diminished ejection
fraction. To avoid these limitations, predicted PPM, which is calculated
by using EOA values provided by the manufacturer divided by the
patient’s BSA, has been introduced to calculate PPM.(2, 3)
PPM leads to higher transprosthetic gradients that may impair mass
myocardial reduction and impair functional capacity and survival after
aortic valve replacement (AVR).(4, 5) Several published studies advocate
the negative impact of PPM on survival.(6-9) Mild or moderate PPM is
commonly found after AVR, ranging from 20% to 70% (10), depending on
the definition and method of calculation. The severity of PPM is the
primary determinant of its influence on clinical outcomes. Although
severe PPM is most responsible for worse long-term survival, it is found
in less than 2% of all AVRs.(7)
Although a similar rate of valve-related complications has been reported
after mechanical and biological prostheses implantation, PPM is more
frequently observed in a biological prosthesis. The impact of structural
valve deterioration in a biological prosthesis and the stable
haemodynamic performance of a mechanical prosthesis on PPM, and
subsequently on survival, is yet to be determined.(11) Besides the
impact of PPM on survival, the question of the quality of life (QoL) of
patients arises. Some authors claim that PPM after AVR diminishes
patients’ physical and mental capacities, especially in an elderly
patient population.(9, 12) Overall, a mechanical prosthesis tends to
have less PPM than a biological prosthesis, but the clinical outcomes
remain unclear.
This study aimed to investigate the impact of an implanted mechanical or
biological prosthesis with PPM on long-term survival and QoL after an
isolated AVR procedure.