Impact of angiographic valve expansion on the hemodynamic outcome in valve-in-valve transcatheter aortic valve replacement

Clinical Research in Cardiology https://doi.org/10.1007/s00392-026-02931-5 ORIGINAL PAPER Impact of angiographic valve expansion on the hemodynamic outcome in valve‑in‑valve transcatheter aortic valve replacement Christoph Höfer1 · Tau Hartikainen1,2 · Maria Lauber1 · Thomas Maulhardt1 · Vera Oettinger1 · Philipp Albrecht1 · Alexander Maier1 · Uwe Zeymer1 · Markus Jäckel1 · Dirk Westermann1 · Constantin von zur Mühlen1 · Jonathan Rilinger1 Received: 7 March 2026 / Accepted: 17 April 2026 © The Author(s) 2026, modified publication 2026 Abstract Background The durability of surgical aortic valve replacement prostheses can be limited due to structural valve deterioration over the years. Because of increased patient age and surgical risk, many of these patients are treated with valve-in-valve transcatheter aortic valve replacement (TAVR). Full expansion of the valve is often difficult to achieve in these patients, which might negatively affect the hemodynamic outcome. Aim The aim was to investigate whether incomplete expansion of valve-in-valve TAVR correlates with an unfavorable hemodynamic outcome. Methods A retrospective monocentric study with 152 patients who received a valve-in-valve TAVR between 2014 and 2024 at the University Heart Centre Freiburg—Bad Krozingen, Germany, was performed. The expansion and implantation depth of the TAVR prostheses were measured in the angiographic recordings and correlated with the postinterventional hemodynamic outcome. Results 69.7% of the patients received self-expanding and 28.9% balloon-expandable TAVR prostheses during the valvein-valve procedure. Under-expansion in the waist area of self-expanding valve prosthesis was associated with increased postinterventional mean pressure gradients. Post-dilation significantly improved the waist expansion in self-expanding valve prostheses (median increase 7.8%, p < 0.0001). Further, a correlation between implantation depth and waist expansion was observed in self-expanding valves (Spearman r − 0.4481, p < 0.0001), but not in balloon-expandable valves. Conclusion Under-expansion of the waist area of self-expanding valve-in-valve TAVR was associated with an unfavorable hemodynamic outcome. A periinterventional measurement of the angiographic images after valve release might be useful to assess a relevant under-expansion and to assist in the indication for post-dilation. Clinical Trials Register The study has been registered in the German Clinical Trials Register (DRKS-ID: DRKS00029242), date: 27/03/2023. * Christoph Höfer 1 Department of Cardiology and Angiology, Faculty of Medicine, University Heart Centre Freiburg - Bad Krozingen, Hugstetter Str. 55, 79106 Freiburg, Germany 2 The Heart Centre, Copenhagen University Hospital, Copenhagen, Denmark Vol.:(0123456789) Clinical Research in Cardiology Graphical abstract Keywords Transcatheter aortic valve replacement · TAVR · Aortic valve stenosis · Valve-in-valve · Under-expansion Abbreviations AUC Area under curve BE Balloon-expandable BMI Body mass index CI Confidence interval CPR Cardiopulmonary resuscitation ECG Electrocardiogram GFR Glomerular filtration rate IQR Interquartile ratio LVEF Left ventricular ejection fraction pmean Postinterventional mean gradient ROC Receiver operating characteristic SAVR Surgical aortic valve replacement SE Self-expanding STS Society of Thoracic Surgeons TAVR Transcatheter aortic valve replacement VARC Valve Academic Research Consortium vmax Postinterventional maximal velocity Introduction The standard therapy for symptomatic aortic valve stenosis or regurgitation is either a surgical aortic valve replacement (SAVR) or a transcatheter aortic valve replacement (TAVR) [1]. However, bioprostheses are subject to degenerative processes, which can cause a relevant new stenosis or regurgitation over time [2]. A second surgical valve replacement can be associated with high operative risks due to advanced age or comorbidities of the patient [3–5]. Many of these patients are therefore treated with a valve-in-valve TAVR [6–8]. Increased postinterventional mean pressure gradients can be observed in many patients after valve-in-valve TAVR, e.g., due to patientprosthesis mismatch or suboptimal position of the prosthesis, and are associated with a higher mortality [8]. Incomplete expansion in TAVR is associated with a higher rate of leaflet stress and thrombosis and has been shown to be associated with higher mortality, re-hospitalization, and stroke [9–11]. Therefore, the optimization of the valve expansion is of great importance in TAVR. Post-dilation is an option to improve the expansion of a TAVR prosthesis, for example, in the case of a relevant under-expansion or a paravalvular leakage [12]. However, only limited data exist for the effect of valve expansion and post-dilation in valve-in-valve TAVR. The aim of the study was to assess the influence of the prosthesis expansion and implantation depth in valve-in-valve TAVR after initial SAVR on the postinterventional hemodynamic outcome. Further, we wanted to investigate the impact of post-dilation on the prosthesis expansion in valve-in-valve TAVR. Methods This study followed the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement [13]. Clinical Research in Cardiology Population We retrospectively included all patients who received a valve-in-valve TAVR after an initial SAVR at the University Heart Centre Freiburg—Bad Krozingen, Germany, between 2014 and 2024. Each patient was evaluated in an interdisciplinary heart team before intervention. In two patients, the intervention was aborted due to complications. Five patients with incomplete or missing postinterventional echocardiography were excluded from the hemodynamic analyses. This study has been approved by the local ethics committee of the University of Freiburg (EK-Freiburg 22–1453-S1). Written informed consent was waived by the ethics committee for this retrospective analysis. The study has been registered in the German Clinical Trials Register (DRKS-ID: DRKS00029242). Assessment of expansion ratio and implantation depth Measurement of valve expansion was carried out using the angiographic recordings of the valve implantation. Recordings were analyzed using DeepUnity Diagnost 2.0.2.2 (Dedalus HealthCare). In representative frames of the final recording, the diameter of the valve prosthesis at inflow, waist, and outflow was measured in a lateral projection (Fig. 1). We divided the measured value by the standard expansion of the valve, provided by the manufacturer and in a previous publication by Valvo et al. [14]. This quotient was defined as the expansion ratio. To exclude the influence of single valve sizes and types, the difference between the measured and the expected gradient, defined as differential gradient, was calculated [15]. The implantation depth was measured from the lower edge of the initial valve to the lower edge of the new prosthe (...truncated)