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.