Advances in interventional treatment of aortic regurgitation
Aortic regurgitation (AR) is a common valvular heart disease. Without timely intervention, it can lead to irreversible myocardial fibrosis and left ventricular dysfunction due to long-term left ventricular volume overload. Patients with severe AR who do not undergo aortic valve replacement have a poor prognosis and high mortality rate. Epidemiological data show that in high-income countries, degenerative changes are the leading cause of AR; while in low- and middle-income countries, rheumatic heart disease is more common. Notably, the detection rate of AR among patients with valvular heart disease in my country is significantly higher than that of aortic stenosis (AS). Therefore, timely and effective intervention for AR is crucial. Compared to surgical valve replacement, transcatheter valve intervention techniques have become a hot topic in clinical research due to their advantages such as minimal invasiveness, rapid recovery, and no need for cardiopulmonary bypass. Transcatheter aortic valve replacement (TAVR), as the core interventional treatment for AR, has shown great potential in clinical practice. However, it faces technical challenges such as the lack of valve calcification anchoring in AR patients and the frequent presence of valve annular dilation, and the success rate using traditional extra-tapered devices is only about 80%. In recent years, with the deepening of clinical exploration, TAVR has made significant progress in the field of AR treatment, covering aspects such as indication updates, clinical research on off-label valves, optimization of surgical strategies, and iteration of dedicated valve devices.
Overview of PAR and Advances in the indications for AR surgical intervention
The 2020 American College of Cardiology/American Heart Association (ACC/AHA) guidelines for valvular heart disease recommend surgical aortic valve replacement (SAVR) for symptomatic severe aortic aortic valve (AR) patients (Class I indications) and asymptomatic patients with severe AR but with left ventricular systolic dysfunction [left ventricular ejection fraction (LVEF) ≤ 55%] or severe left ventricular enlargement [left ventricular end-systolic diameter (LVESD) > 50 mm or left ventricular end-systolic diameter index (LVESDi) > 25 mm/m²] (Class II indications). The 2021 European Society of Cardiology (ESC/EACTS) guidelines for valvular heart disease continue these surgical indications and, for the first time, suggest TAVR for severe AR patients with contraindications to surgery or at high risk, but do not specify a recommendation level. The 2025 ESC/EACTS guidelines for the management of valvular heart disease have made important updates to the treatment strategy for aortic valve disease (AR): (1) For symptomatic severe AR patients who are assessed by a multidisciplinary cardiac team as unsuitable for surgery, if the anatomical conditions are suitable, TAVR treatment is recommended (Class IIb indication, Level B evidence). This is the first time that the recommendation level has been clearly defined, which marks a milestone breakthrough in the field of AR treatment and provides new evidence-based treatment options for such patients; (2) The new guidelines have optimized their assessment system and proposed that for asymptomatic severe AR patients, if there is LVESDi > 22 mm/m², left ventricular end-systolic volume index (LVESVi) > 45 ml/m² (especially patients with body surface area < 1.68 m²), or resting LVEF ≤ 55% and the surgical risk is low, aortic valve surgery can be considered to block the process of left ventricular remodeling through early intervention and avoid irreversible myocardial damage.
Advances in TAVR treatment for AR
In the treatment of acute atrial fibrillation (AR), subarachnoid renal replacement therapy (SAVR) has long been used as a first-line treatment. However, its invasive nature leads to a higher incidence of complications and mortality in elderly and high-risk patients. In recent years, transabdominal renal replacement therapy (TAVR), with its minimally invasive advantages, has gradually become an important alternative to surgery, and multiple studies have confirmed its value. A study in the US Medicare database (11,027 cases) showed that for patients with isolated primary AR (PNAR), TAVR was comparable to SAVR in short-term safety, with significantly fewer complications such as in-hospital acute kidney injury, transfusion requirements, and new-onset atrial fibrillation. The length of hospital stay was shortened to 2 days (compared to 6 days with SAVR), and there was no statistically significant difference in 30-day mortality. A nationwide study in Germany (4,861 cases) showed that although patients in the TAVR group had higher baseline risk, their incidence of complications such as in-hospital hemorrhage (2.19% vs. 21.64%) and delirium (6.13% vs. 15.93%) was significantly lower than that in the SAVR group. These studies indicate that TAVR has the potential to replace surgery in terms of short-term efficacy and safety. Other studies have shown that TAVR is a reasonable alternative in rigorously screened high-risk AR patients. However, current TAVR research in the AR field still lacks randomized controlled trial data, with only studies such as SEASON-AR and ARTIST in the planning or implementation stages. The SEASON-AR trial (NCT04864145) is the world’s first multicenter randomized controlled trial for high-risk primary severe AR, aiming to fill the evidence-based medicine gap in the treatment of this disease. This study plans to enroll 210 patients, with the primary endpoint being major adverse cardiovascular events (MACE) at 12 months, and will follow up for 5 years. Furthermore, the ongoing ARTIST international multicenter study aims to evaluate surgical options for AR patients (TAVR vs. SAVR) through randomized controlled trials, which will help to more comprehensively assess the relative advantages of TAVR and SAVR in AR treatment and clarify the optimal application strategy for TAVR in AR patients with different risk levels and anatomical structures. In the future, with the development and iteration of dedicated valves and the improvement of long-term follow-up data, TAVR is expected to further expand its indications.
China has made continuous breakthroughs in the field of interventional treatment for isolated aortic regurgitation (AR), establishing a standardized clinical system based on international advancements and tailored to the characteristics of the Chinese population. The “Chinese Expert Consensus 2023 on Transfemoral Aortic Valve Replacement for Isolated Aortic Regurgitation,” as the first international consensus specifically addressing transfemoral aortic valve replacement (TFTAVR) for isolated AR, is based on Chinese clinical experience and integrates the latest domestic and international findings. Its main purpose is to provide support and guidance for the safe and standardized development of TF-TAVR in AR treatment. The consensus clearly defines high-risk surgical patients with moderate to severe or severe AR and suitable anatomy as the core population for TF-TAVR, and standardizes the entire process from preoperative assessment (emphasizing precise assessment of anatomical structures using ultrasound and CT vascular ultrasound multimodal imaging), intraoperative procedures (recommending techniques such as non-coronary sinus pivot (NCPI) and “sandwich” valve-in-valve techniques to improve stability and reduce complication rates), to postoperative management (focusing on valve displacement, conduction block prevention, and antithrombotic strategies). Simultaneously, the consensus proposes that prospective studies be conducted to verify the long-term efficacy of domestically produced TF-TAVR devices, promoting the development of AR treatment towards precision and standardization. The “Expert Consensus on Clinical Pathways for Transcatheter Aortic Valve Replacement in China (2024 Edition)” innovatively proposes a CT dual-anchoring multiplanar measurement scheme and anatomical classification for TAVR intervention in patients with isolated aortic valve replacement (AR), emphasizing the importance of anatomical appropriateness. At the same time, it shifts the intervention timing from “symptom onset” to the “subclinical cardiac function impairment” stage, aligning with international cutting-edge management concepts and reflecting the safety and quality control of AR patient treatment.
Advances in clinical research of external valves
Since its initial clinical application, TAVR has primarily focused on the treatment of ankylosing spondylitis (AS), significantly improving patient outcomes due to its minimally invasive advantages. With deepening clinical exploration, TAVR technology is gradually breaking through its original indications, expanding its application scope to the field of atrial fibrillation (AR). In clinical practice, AS-specific valves are often used off-label for AR treatment; this strategy, while challenging, has accumulated a wealth of clinical evidence.
Multiple AR comparative studies have compared the efficacy, safety, and technical compatibility of self-expanding valves versus bulbar expander-labeled off-label valves in AR treatment. Next-generation off-label self-expanding valves (such as Evolut R) provide continuous radial support through the self-expanding properties of a nickel-titanium alloy frame, achieving stable anchoring in non-calcified anatomy. Combined with a retrievable/repositionable design, they demonstrate significant advantages in AR treatment. Studies show that although this device can be made oversized to fit patients with large annulus valves, its valve anchoring stability is significantly reduced in non-calcified anatomy; furthermore, this valve relies on mechanical expansion, with an average oversize rate of 17.9%, potentially increasing the risk of complications. The “Chinese Expert Consensus on Aortic Valve Replacement via Femoral Artery for Isolated Aortic Regurgitation 2023” further points out that if displacement occurs after self-expanding valve placement, it can be salvaged using valve-in-valve techniques; however, displacement of bulbar valves often requires surgical intervention, and the displacement rate is relatively high (3.5%~10.8%). In summary, self-expanding valves, with their non-calcification-dependent dynamic radial support and retrievability, have become the preferred option for AR-labeled external valve treatment; bulbar valves, due to their greater reliance on calcification anchoring, are only recommended for specific scenarios with large annulus valves and where specialized instruments are unavailable, and their application requires strict preoperative anatomical assessment.
Application Exploration and Challenges in AR Patients: The value of anatomical assessment in TAVR has been fully validated. It is not only a prerequisite for guiding valve size selection but also a key step in optimizing placement strategies and reducing surgical complications. In the exploration of AR treatment, when using off-label external valves, the annulus circumference is a key factor affecting the prognosis of TF-TAVR. The AURORA study further proposed a novel anatomical classification system to screen suitable patients for tag-assisted self-expanding valve treatment. This system achieved a 91% success rate, no intraoperative deaths, and a pacemaker implantation rate of only 9%, suggesting that optimizing the valve-aortic root structure match based on individual anatomical characteristics may be a safer and more effective treatment option.
Patients with isolated aortic regurgitation (AR) commonly exhibit an enlarged valve annulus. Therefore, intervention strategies targeting large valve annulus have become a focus of clinical research. Bhaskaran et al., in patients with non-calcified AR and a large valve annulus (area 722 mm², diameter >30 mm), used a 35 mm Myval XXL bulb expansion combined with a 24 Fr Python BZ Smart intubation sheath for TAVR. Through precise valve positioning and a slow inflation strategy, they achieved a postoperative aortic valve pressure gradient of 0 and no paravalvular leakage. A 30-day follow-up showed that the patient’s cardiac function remained well maintained (NYHA functional class I).
New tag-type external valve technology
Because the pathological mechanism of atrial valvular regurgitation (AR) mainly manifests as malalignment of the valve leaflets or dilation of the valve annulus, leading to valvular regurgitation, and because it lacks the anchoring force provided by leaflet calcification commonly found in patients with ankylosing spondylitis (AS), traditional TAVR valve devices designed for AS have limitations when applied to AR patients, resulting in a significantly lower surgical success rate compared to AS treatment. To improve surgical outcomes, clinicians have gradually explored various targeted surgical strategies, significantly improving the surgical prognosis of high-risk AR patients.
Specialized TAVR valve treatment
Advances in Atrial Valve Regurgitation (AR) Treatment: In recent years, TAVR devices for AR treatment have undergone continuous iteration. Early off-label devices, when used off-label for AR, suffered from insufficient anatomical compatibility, limited efficacy, and high complication risks, prompting the development and application of dedicated devices to become a focus. Among them, the J-Valve, approved by the National Medical Products Administration in 2017 via the transapical approach, was an early dedicated device for AR. Although it partially solved the fixation problem of native valve regurgitation through its unique anchoring design, its clinical adoption was limited by the invasiveness of open-chest puncture, the complexity of the procedure, and the risk of postoperative complications. Therefore, minimally invasive dedicated devices via the femoral artery approach have become a research hotspot, and significant breakthroughs have been achieved in this area.
Future Outlook
Significant progress has been made in interventional treatment of atrial fibrillation (AR), including expanded indications, accumulation of clinical evidence, optimization of surgical strategies, and development of specialized devices. However, further exploration from multiple dimensions is needed to advance clinical practice. Current research has confirmed the short-term safety and technical feasibility of transcatheter atrial revascularization (TAVR) in high-risk surgical AR patients, but long-term efficacy still needs validation, including valve durability, sustained improvement in left ventricular remodeling, and the benefit boundary in low- and intermediate-risk populations. Anatomical complexity remains a key challenge; non-calcified anatomy requires moving beyond traditional calcification-based anchoring, and ultra-large annulus valves require the integration of occluder-assisted anchoring techniques or the development of larger-sized specialized valves. Furthermore, clinical data from original Chinese devices need to be integrated into international guidelines to optimize operational procedures suitable for Asian populations, while strengthening individualized management of end-stage patients by multidisciplinary teams. Device innovation should focus on intelligent anchoring and material innovation. Polymer valves, such as SIKELIA, with their high biocompatibility, durability, and low calcification, are driving the optimization and upgrading of TAVR valves. In the future, long-term follow-up, precise anatomical classification, and multi-center collaboration are needed to promote the transformation of AR interventional therapy from “high-risk rescue” to “early intervention for the entire population,” ultimately achieving a dual improvement in efficacy and quality of life.