Klautz, Robert J M

Abstract A recent discussion that highlighted the differences between the reported effective orifice area and corresponding incidence of prosthesis-patient mismatch within the 1- and 7-year results of the PERIcardial SurGical AOrtic Valve ReplacemeNt (PERIGON) Trial of the Avalus valve has once again emphasized the instability of such measurements. The effective orifice area, calculated using the continuity equation through measurements of the left ventricular outflow tract diameter, is highly susceptible to measurement variability, as previously demonstrated in literature through both intra- and interobserver variability. To illustrate this problem, a simulation was performed in which the left ventricular outflow tract diameter was systematically altered by −2 mm, −1 mm, 0 mm, +1 mm, and +2 mm. Subsequently, the proportion of severe prosthesis-patient mismatch was recalculated and varied between 13.3%, 6.2%, 3.1% (original), 1.2%, and 0.3%, respectively. These findings demonstrate that small but clinically realistic variability in left ventricular outflow tract measurements can significantly affect the presence of prosthesis-patient mismatch. A measurement variability of 1 mm can nearly double or halve the prevalence of severe prosthesis-patient mismatch. This illustrates that prosthesis-patient mismatch, in its current form, is highly unstable and that indexed effective orifice area-based prosthesis-patient mismatch should not be used in isolation.

Abstract OBJECTIVES The objective of this analysis was to assess the normal haemodynamic performance of contemporary surgical aortic valves at 1 year postimplant in patients undergoing surgical aortic valve replacement for significant valvular dysfunction. By pooling data from 4 multicentre studies, this study will contribute to a better understanding of the effectiveness of surgical aortic valve replacement procedures, aiding clinicians and researchers in making informed decisions regarding valve selection and patient management. METHODS Echocardiograms were assessed by a single core laboratory. Effective orifice area, dimensionless velocity index, mean aortic gradient, peak aortic velocity and stroke volume were evaluated. RESULTS The cohort included 2958 patients. Baseline age in the studies ranged from 70.1 ± 9.0 to 83.3 ± 6.4 years, and Society of Thoracic Surgeons risk of mortality was 1.9 ± 0.7 to 7.5 ± 3.4%. Twenty patients who had received a valve model implanted in fewer than 10 cases were excluded. Ten valve models (all tissue valves; n = 2938 patients) were analysed. At 1 year, population mean effective orifice area ranged from 1.46 ± 0.34 to 2.12 ± 0.59 cm2, and dimensionless velocity index, from 0.39 ± 0.07 to 0.56 ± 0.15. The mean gradient ranged from 8.6 ± 3.4 to 16.1 ± 6.2 mmHg with peak aortic velocity of 1.96 ± 0.39 to 2.65 ± 0.47 m/s. Stroke volume was 75.3 ± 19.6 to 89.8 ± 24.3 ml. CONCLUSIONS This pooled cohort is the largest to date of contemporary surgical aortic valves with echocardiograms analysed by a single core lab. Overall haemodynamic performance at 1 year ranged from good to excellent. These data can serve as a benchmark for other studies and may be useful to evaluate the performance of bioprosthetic surgical valves over time. Clinical trial registration number NCT02088554, NCT02701283, NCT01586910 and NCT01531374.