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 Safety, efficacy and durability are important considerations when selecting a bioprosthesis for aortic valve replacement (AVR). This study assessed 7-year clinical outcomes and haemodynamic performance of the Avalus bioprosthesis. METHODS Patients indicated for surgical AVR were enrolled in this prospective, nonrandomized trial, conducted across 39 sites globally. The primary end-point of this analysis was freedom from surgical explant or percutaneous valve-in-valve reintervention due to structural valve deterioration (SVD) at 7 years of follow-up, determined using Kaplan–Meier (KM) analysis. We also evaluated a composite end-point of SVD and/or severe haemodynamic dysfunction requiring reintervention. Survival, valve-related safety events and haemodynamic performance were assessed. Deaths and safety events were adjudicated by an independent clinical events committee. RESULTS A total of 1132 patients underwent surgical AVR. Mean age was 70 years; 854 patients (75%) were men. The mean STS risk of mortality was 2.0 ± 1.4%, and 659 patients (58%) had a New York Heart Association classification of I/II. One or more concomitant procedures were performed in 577 patients (51%). At 7 years, the Kaplan–Meier rate of freedom from SVD/severe haemodynamic dysfunction requiring reintervention was 1.2% (0.5–2.5%) with no cases adjudicated as SVD. The survival rate was 82.6% (79.5–85.0%). The KM event rate was 5.7% (4.3–7.7%) for reintervention, 6.3% (4.9–8.3%) for endocarditis and 0.4% (0.1–1.1%) for valve thrombosis. Mean aortic gradient, dimensionless velocity index and effective orifice area were 13.8 ± 5.9 mmHg, 0.42 ± 0.09 and 1.99 ± 0.53 cm2, respectively. CONCLUSIONS This analysis demonstrated excellent durability of the Avalus valve with good clinical outcomes and stable haemodynamic performance through 7 years of follow-up.

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.

Objective To describe differences between North America and Europe in the perioperative management of patients undergoing surgical aortic valve replacement (SAVR). Methods Patients with moderate or greater aortic stenosis or regurgitation requiring SAVR were enrolled in a prospective observational cohort evaluating the safety and efficacy of a new stented bioprosthesis at 25 centres in North America (Canada and the USA) and 13 centres in Europe (Germany, the Netherlands, France, the UK, Switzerland and Italy). While all patients underwent implantation with the same bioprosthetic model, perioperative management was left to the discretion of participating centres. Perioperative care was described in detail including outcomes up to 1-year follow-up. Results Among 1118 patients, 643 (58%) were implanted in North America, and 475 (42%) were implanted in Europe. Patients in Europe were older, had a lower body mass index, less bicuspid disease and worse degree of aortic stenosis at baseline. In Europe, anticoagulant therapy at discharge was more aggressive, whereas length of stay was longer, and discharges directly to home were less common. Rehospitalisation risk was lower in Europe at 30 days (8.5% vs 15.9%) but converged at 1-year follow-up (26.5% vs 28.1%). Within continents, there were major differences between individual countries concerning perioperative management. Conclusion Contemporary perioperative management of SAVR patients varies between North America and Europe in patient selection, procedural techniques, antithrombotic regimen and discharge management. Furthermore, rehospitalisation differed largely between continents and countries. Hence, geographical setting must be considered during design and interpretation of trials on SAVR. Trial registration number NCT02088554.