Comparative effectiveness of devices for transcatheter closure of atrial septal defects: Systematic review and network meta-analysis

Atrial septal defect is a common congenital heart disease, producing a left-to-right shunt in the atrial septum; the current preferred treatment is transcatheter device closure. The aim is to conduct a systematic review to synthesize information on the comparative effectiveness and safety of atrial septal defect closure devices. The methods used: a comprehensive search of Ovid MEDLINE®, Embase, and Cochrane Central databases was conducted. Studies comparing procedural and follow-up outcomes of atrial septal defect devices were included. Network meta-analyses were conducted to generate direct and indirect evidence for comparative effectiveness and safety outcomes between devices. The results are as follows: Twelve studies met our inclusion criteria and were compared in network meta-analyses. The meta-analyses evaluated contemporary devices: the AMPLATZER Septal Occluder; the GORE CARDIOFORM Septal Occluder; the Figulla Flexible II Occluder; the CeraFlex Septal Occluder; and the HELEX Septal Occluder. These studies represented 3998 patients. The primary safety and efficacy outcomes were device embolization and follow-up residual shunt, respectively. Secondary clinical outcomes included procedural success and major and minor complications. No differences were found between devices in terms of device embolization and secondary clinical outcomes. Follow-up residual shunt was higher with the HELEX Septal Occluder compared with the AMPLATZER Septal Occluder (odds ratio 2.92, 95% confidence interval 1.12-7.61). To conclude: although most outcomes were similar between devices, evidence was largely based on observational low-quality studies. There were inconsistencies in outcome reporting and definitions; this merits future studies, with head-to-head device comparisons and standardization of outcomes.

Safety and Efficacy of the Amplatzer Septal Occluder: A Systematic Review and Meta-Analysis

OBJECTIVES

To assess the safety and efficacy of the Amplatzer Septal Occluder in the closure of secundum type atrial septal defects.

BACKGROUND

The Amplatzer Septal Occluder (ASO; Abbott, St. Paul, MN) is an FDA-approved device for percutaneous closure of secundum type atrial septal defects (ASD). Previous small cohort trials have shown a favorable safety and technical efficacy profile.

METHODS

We conducted a systemic review and meta-analysis of all prospective case series and controlled trials that evaluated the ASO's safety and implant efficacy. The primary endpoint was the technical success rate of implantations. Secondary outcomes included proportions of arrhythmias and embolism specific-adverse events.

RESULTS

We included a total of 12 studies with 2972 patients. The ratio of device implantation was 2:1 by sex [female: male]. Pooled technical success rate of implantation was 98% (95% CI: 0.968-0.990, P < 0.01). The cumulative adverse event rate was 5.1% (95% CI: 0.035-0.068, P < 0.01), which included arrhythmia and embolism specific adverse event rates of 1.8% (95% CI: 0.007-0.032, P < 0.01) and 0.7% (95% CI: 0.002-0.013, P < 0.01), respectively. Sensitivity analysis did not significantly affect pooled outcomes for success rate and adverse events; both forest plot and Begg's and Egger's regression tests supported symmetricity.

CONCLUSION

A high likelihood of technical success can be expected when implanting the ASO in secundum type ASDs. Adverse event rates are expected for one in twenty patients, and thus, our results support the safe use of ASO in secundum type ASDs closure.

CONDENSED ABSTRACT

The AMPLATZER Septal Occluder is an FDA-approved device for percutaneous closure of secundum type atrial septal defects (ASD). We conducted a systemic review and meta-analysis of all prospective case series and controlled trials that evaluated the ASO's safety and implant efficacy. We included a total of 12 studies with 2972 patients. Pooled technical success rate of implantation was 98% (P < 0.01). The cumulative adverse event rate was 5.1% (P < 0.01), 1.8% (P < 0.01) rate of arrhythmias, and 0.7% (P < 0.01) rate of embolisms. A high likelihood of technical success can be expected with a low rate of adverse events.

Complications of trans-catheter closure of atrial septal defects

Trans-catheter device closure of atrial septal defects (ASD) is considered to be safe with minimal complications. But, there are certain complications that arise after these device closures which might require urgent or late surgical intervention. We have retrospectively analysed our experience. Out of 780 patients who underwent device closure, 11 (1.4%) patients required urgent surgical intervention to retrieve the embolized device. The size of the ASD, expertise of the cardiologist and the type of the device directly impacted the rate of device embolization. Early diagnosis and prompt surgical retrieval is paramount before any life threatening complications arise due to the embolized device. One patient developed infective endocarditis later, which required surgery. Regular long term follow up is needed after these procedures to diagnose the complications earlier so that prompt surgical intervention could be done.

Recent developments in next-generation occlusion devices

Transcatheter closure has been widely accepted as a highly effective way to treat abnormal blood flows and/or embolization of thrombus in the heart. It allows the closure of four types of congenital heart defects (CHDs) and stroke-associated left atrial appendage (LAA). The four types of CHDs include atrial septal defect (ASD), patent foramen ovale (PFO), patent ductus arteriosus (PDA), and ventricular septal defect (VSD). Advancements in the materials and configurations of occlusion devices have spurred the transition from open-heart surgery with high complexity and morbidity, or lifelong medication with a high risk of bleeding, to minimally invasive deployment. A variety of occlusion devices have been developed over the past few decades, particularly novel ones represented by biodegradable and 3D-printed occlusion devices, which are considered as next-generation alternatives to conventional Nitinol-based occlusion devices due to biodegradability, customization, and improved biocompatibility. The aim here is to comprehensively review the next-generation occlusion devices in terms of materials, configurations, manufacturing methods, deployment strategies, and (if available) experimental results or clinical data. The current challenges and the direction of future work are also proposed. STATEMENT OF SIGNIFICANCE: Implantation of occlusion devices has become a widely accepted and highly effective treatment for occluding abnormal blood/thrombus flow within the heart. Due to the serious complications such as erosion and displacement of conventional Nitinol-based occluders, next-generation occluders with reduced risk of complications and improved biocompatibility has emerged. Here, we comprehensively review the next-generation occluders developed for atrial septal defect (ASD), patent foramen ovale (PFO), patent ductus arteriosus (PDA), ventricular septal defect (VSD), and left atrial appendage (LAA), with special emphasis on biodegradable occluders. Besides, intelligent materials (e.g., automatically deployable shape memory polymers) and rapid customized manufacturing methods (3D/4D printing) for the fabrication of occluders are also introduced. Lastly, the directions of future work are highlighted.

Biodegradable atrial septal defect occluders: A current review

Atrial septal defect (ASD) is a common structural congenital heart disease. With the development of interventional closure devices and transcatheter techniques, interventional closure therapy has become the most well-accepted therapeutic alternative worldwide, as it offers a number of advantages over conventional therapies such as improved safety, easier operation, lower complication rates and invasiveness, and shorter anesthetic time and hospitalizations. During the past decades, various types of occluders based on nondegradable shape memory alloys have been used in clinical applications. Considering that the permanent existence of foreign nondegradable materials in vivo can cause many potential complications in the long term, the research and development of biodegradable occluders has emerged as a crucial issue for interventional treatment of ASD. This review aims to summarize partially or fully biodegradable occlusion devices currently reported in the literature from the aspects of design, construction, and evaluation of animal experiments. Furthermore, a comparison is made on the advantages and disadvantages of the materials used in biodegradable ASD occlusion devices, followed by an analysis of the problems and limitations of the occlusion devices. Finally, several strategies are proposed for future development of biodegradable cardiac septal defect occlusion devices. STATEMENT OF SIGNIFICANCE: Although occlusion devices based on nondegradable alloys have been widely used in clinical applications and saved numerouspatients, biodegradable occlusion devices may offer some advantages such as fewer complications, acceptable biocompatibility, and particularly temporary existence, thereby leaving "native" tissue behind, which will certainly become the development trend in the long term. This review summarizes almost all partially or fully biodegradable occlusion devices currently reported in the literature from the aspects of design, construction, and evaluation of animal experiments. Furthermore, a comparison is made on the advantages and disadvantages of the materials used in biodegradable ASD occlusion devices, followed by an analysis of the problems and limitations of the occlusion devices. Finally, several strategies are proposed for future development of biodegradable cardiac septal defect occlusion devices.

Translation in cardiovascular stents and occluders: From biostable to fully degradable

Cardiovascular disease is a major cause of morbidity and mortality, especially in developed countries. Most academic research efforts in cardiovascular disease management focus on pharmacological interventions, or are concerned with discovering new disease markers for diagnosis and monitoring. Nonpharmacological interventions with therapeutic devices, conversely, are driven largely by novel materials and device design. Examples of such devices include coronary stents, heart valves, ventricular assist devices, and occluders for septal defects. Until recently, development of such devices remained largely with medical device companies. We trace the materials evolution story in two of these devices (stents and occluders), while also highlighting academic contributions, including our own, to the evolution story. Specifically, it addresses not only our successes, but also the challenges facing the translatability of concepts generated via academic research.

Historical developments of atrial septal defect closure devices: what we learn from the past

INTRODUCTION

Since King and Mills' pioneering work in percutaneous closure devices of secundum atrial septal defects (ASD) four decades ago, developments in device shape, material and implantation technique led to adoption of percutaneous ASD closure as current treatment of choice. Not only was the feasibility of such a percutaneous procedure tested altogether, but pursuing the ideal device in terms of safety and efficacy became priority.

AREAS COVERED

In this review we present the historical development of ASD devices in design, material and technique with clinical data, and provide the future perspectives in percutaneous ASD closures.

EXPERT OPINION

An 'ideal device' requires complete defect closure with negligible risk of complications using a safe, straightforward delivery technique with repositioning and retrieving properties. Some of the devices currently at hand come close to fulfilling these criteria, however none seem to provide those prerequisites completely. By understanding how challenges in device development were overcome in the past, new insights into future improvements are given.

Current perspectives in percutaneous atrial septal defect closure devices

In the last decade, percutaneous atrial septal defect (ASD) closure has become the treatment of choice in most clinical presentations of ASD. Percutaneous ASD closure has established procedural safety through operator experience and improved device structure and deliverability. There have also been advances in diagnostic capabilities. Devices have evolved from large bulky meshes to repositionable, minimal residual mesh content that easily endothelializes and conforms well to surrounding structures. Biodegradable technology has been introduced and will be closely watched as a future option. The evolution of ASD closure device usage in the last four decades incorporates development that minimizes a wide range of serious side effects that have been reported over the years. Complications reported in the literature include thrombus formation, air embolization, device embolization, erosions, residual shunts, and nickel hypersensitivity. Modern devices have intermediate to long term data with outcomes that have been favorable. Devices are available in multiple sizes with improved delivery mechanisms to recapture, reposition, and safely close simple and complex ASDs amenable to percutaneous closure. In this review, commonly used devices and deployment procedures are discussed together with a look at devices that show promise for the future.