First Purpose-Built PVL Occluder Wins FDA Nod Amid Durability Doubts

Abbott's Amplatzer Paraclose PVL Occluder Receives FDA Approval

Abbott announced U.S. Food and Drug Administration (FDA) approval for its Amplatzer™ Paraclose PVL Occluder, the first and only transcatheter device specifically designed to treat paravalvular leak (PVL) without requiring additional open-heart surgery. PVL, a backflow of blood around a replacement heart valve, affects 7-17% of mitral and 5-10% of aortic valve replacements, leading to symptoms like heart failure and severe anemia. This minimally invasive device, delivered via catheter through the leg, offers a crucial alternative to repeat surgical intervention. The approval was supported by positive clinical data from the PARADIGM study, which enrolled 200 patients and demonstrated the device's safety and effectiveness.

• Addressing a Significant Unmet Need in PVL Treatment: Paravalvular leak (PVL) is a serious complication following heart valve replacement, occurring in 7% to 17% of mitral and 5% to 10% of aortic valve replacements. It causes debilitating symptoms such as heart failure and severe anemia, often necessitating repeat open-heart surgery. The Amplatzer Paraclose PVL Occluder fills a critical gap by providing the first and only FDA-approved minimally invasive, transcatheter alternative, significantly reducing patient risk and recovery time compared to traditional surgical reoperation.
• Innovative Device Design and Minimally Invasive Delivery: The Amplatzer Paraclose PVL Occluder features a unique elliptical/oblong shape, specifically engineered to effectively close a wide range of PVL anatomies. This design is crucial for adapting to the varied and complex gaps that can form between native heart tissue and replacement valves. The device is implanted through a catheter inserted via an artery or vein in the leg, offering a less invasive procedure that avoids the complexities and recovery associated with repeat open-heart surgery.
• Clinical Validation from the PARADIGM Study: FDA approval was based on robust clinical data from the PARADIGM study, a prospective, multicenter, single-arm trial involving 200 patients. This study demonstrated the Amplatzer Paraclose PVL Occluder's safety and effectiveness as a minimally invasive treatment for PVL. The positive outcomes from PARADIGM reinforce the device's capability to provide an effective solution, offering patients a viable and less burdensome alternative to repeat surgical interventions for this challenging condition.

The Limitations of Current Approaches for Paravalvular Leak

Transcatheter closure of paravalvular leak (PVL) is an intricate alternative to surgical closure, but it represents one of the most intricate procedures in the field of structural heart interventions, especially for patients with mitral PVL. Redo surgery can be definitive, yet contemporary candidates frequently carry prohibitive operative risk, positioning transcatheter closure as a key therapeutic alternative with its own constraints.

• Technical complexity and anatomic constraints: Closure is hampered by technical challenges and the complex anatomy of PVL channels, including irregular and crescentic defects, with risk of interference between the implanted occluder and surrounding structures such as prosthetic leaflets, the coronary sinus and left circumflex coronary artery. Outcomes remain strongly influenced by leak morphology, prosthetic valve characteristics, access route, and operator experience, requiring complex catheter techniques including transfemoral, transapical, transseptal via an arteriovenous loop, retrograde, and transbrachial access.

• Lack of purpose-specific devices with off-label repurposing: Current transcatheter closure devices are off-label and repurposed from other indications, including Vascular Plug III, Amplatzer Vascular Plug II, Amplatzer Duct Occluder II, patent ductus arteriosus occluder, Amplatzer muscular ventricular septal defect occluder, and ventricular septal defect occluder. The lack of closure devices specifically designed for this purpose limits optimal sealing of elongated crescentic channels, particularly in hemolysis-predominant presentations, often requiring modular multi-device strategies.

• Imaging limitations and lack of standardized protocols: Management relies on multimodality imaging, with echocardiography as the backbone of diagnosis and quantification and cardiac computed tomography and cardiac magnetic resonance imaging for defect characterization and periprocedural planning. Limitations include the limitations of available imaging modalities, heterogeneous imaging protocols, nonuniform endpoint definitions, and absence of standardized protocol for predicting neo-left ventricular outflow tract obstruction and evaluating anatomical feasibility.

• Surgical risk and procedural complications: Reoperation is associated with high rates of morbidity and mortality, with risks of repeat operation and re leak significantly higher than the original valve-replacement surgical risks. Transcatheter procedures carry complications including recurrent hemolysis, residual regurgitation, acute renal insufficiency, anemia, device migration, valve thrombosis, leaflet impingement, embolization, stroke, vascular injury, tamponade, pericardial bleeding, pseudoaneurysm, coronary obstruction, and paravalvular leak.

• Limited quality and durability of evidence: Available outcome data are largely derived from observational series and registries with heterogeneity in PVL mechanisms, prosthesis types, imaging protocols, and endpoint definitions. Important limitations include the absence of randomized trials, nonuniform endpoint definitions, heterogeneous imaging protocols, and limited long-term comparative durability data.

PARADIGM Study: Design and Endpoints Supporting Approval

Paravalvular leak evaluation spans single-center series, multicenter registries, and comparative analyses of transcatheter closure versus surgery. Designs are primarily retrospective or prospective observational cohorts in high surgical risk patients, with technical success, clinical success, mortality, and residual leak as key endpoints.

Integrating Amplatzer Paraclose into PVL Treatment Guidelines

Surgical reoperation has been the standard treatment for paravalvular leak after surgical valvular replacement, but it is associated with high morbidity and mortality. Surgical reintervention of PVLs is associated with high mortality rates, and interventional closure of paravalvular leaks by plug implantation has emerged as an alternative to surgical correction, which is associated with high mortality rates for re-operation.

Transcatheter closure is a therapeutic alternative with high rates of technical, echocardiographic, and clinical success in the short and medium term. Transcatheter PVL closure (TPVLc) has emerged as an alternative to surgical reoperation, and percutaneous repair of paravalvular prosthetic regurgitation may be an initial therapeutic option, particularly in patients at significant risk for open surgery. It is an adequate therapeutic alternative, mainly in high surgical risk patients and multiples comorbidities.

For paravalvular leaks following transcatheter aortic valve replacement (TAVR), current evidence on PVL management is limited. In most cases, a conservative approach is adopted, while interventional strategies (such as pre- and post-dilatation, percutaneous PVL closure, and TAVR-in-TAVR) are reserved for selected patients. Comparison of the recommendations from the 2017 American College of Cardiology/American Heart Association guidelines for management of patients with prosthetic heart valves with the 2017 European Society of Cardiology guidelines showed the 2 documents differed regarding recommendations for follow-up imaging, the choice of biological versus mechanical prosthesis, bridging therapies, role of aspirin, use of fibrinolytic therapy for prosthetic valve thrombosis, and management of paravalvular regurgitation.