Transcatheter closure of multiperforated atrial septal defect

INTRODUCTION

Atrial septal defect (ASD) is the congenital heart disease most frequently diagnosed in adulthood, with the ostium secundum type being the most prevalent (80% of cases). Since the first transcatheter closures of atrial septal defects, advances in both experience and devices have made the transcatheter technique the method of choice for most patients. However, some specific cases, such as ASDs with multiple defects or multi-fenestrated ASDs (mASDs), which account for 10% of all patients with ostium secundum type ASD, continue to pose diagnostic and therapeutic challenges. Furthermore, the available scientific evidence in this subgroup is scarce.1-4

The objective of our study was to analyze and compare the results of the transcatheter closure of mASD vs the transcatheter closure of the remaining patients with ostium secundum type ASD.

METHODS

Study design and population

We conducted a retrospective study that included all cases of transcatheter ASD closure performed in adults older than 18 years at our center from October 2014 through October 2024.

The patients’ demographic, echocardiographic, and hemodynamic data were collected, including a 6-month follow-up following the intervention, assessing residual shunt and echocardiographic parameters such as right ventricular remodeling. This is a retrospective study in which the patients’ informed consent was obtained for the use of their interventional procedure for research purposes. The authors confirm that the interventions were performed in full compliance with the regulations of the Clinical and Ethical Research Committee and the Declaration of Helsinki of the World Medical Association.

Endpoints

The primary endpoint of this study is to analyze the clinical and echocardiographic results of the transcatheter closure of mASDs. Similarly, these results are compared with those obtained after the transcatheter closure of simple (non-multi-fenestrated) ostium secundum type ASDs.

Statistical analysis

Qualitative variables are expressed as percentages and the continuous ones as mean and standard deviation, or as median with interquartile range, depending on whether they follow a normal distribution. For inter-group comparison, the chi-square test or Fisher’s exact test was used for qualitative variables, and the Student’s t-test or the Mann-Whitney U test for continuous variables, as appropriate. The threshold for statistical significance was set at P < .05. Analyses were performed with SPSS software (version 21; IBM Corp, Armonk, NY, United States).

RESULTS

During the study period, a total of 67 transcatheter closures of ostium secundum type ASDs were performed in patients older than 18 years. The patients’ baseline characteristics and ASDs, the procedure, and the results are shown in table 1. The mean age of the population was 52 years, with a predominance of women (65%). The most common indication for ASD closure was dilation of the right ventricular dilatation (88%). In most cases (91%), transcatheter closure was performed with a single device; however, due to anatomical complexity, 5 patients required 2 devices and 1, 3 devices. The combination of transthoracic echocardiography (TTE) and fluoroscopy was the advanced imaging modality selected to guide the procedure in 65% of cases. Four out of all patients had perioperative complications. Three of these complications were due to device embolization, and all recovered uneventfully; 1 patient presented paroxysmal atrial flutter that required pharmacological cardioversion with amiodarone. All patients progressed favorably and were discharged at 24 hours without complications. At follow-up, 82% had no residual shunt, and zero cases of grade ≥ II shunt were found.

Table 1. Baseline characteristics of all patients undergoing transcatheter atrial septal defect closure

Twelve out of all the patients with ASD closure (18%) had ≥ 2 atrial septal defects, whose characteristics are shown in table 2. The patients’ mean age was 42 years, with an equitable sex distribution. Right heart dilatation was the most common reason for closure (83%), with 2 patients presenting with strokes. All patients were in New York Heart Association functional class I-II/IV.

Table 2. Baseline characteristics, procedure, and outcomes of patients undergoing transcatheter closure of multi-fenestrated atrial septal defects

Regarding the echocardiographic study of mASDs, all patients underwent a TEE prior to the procedure. Patients had between 2 (66% of cases) and 4 atrial septal defects. The most common location of the largest defect was anterosuperior (10 patients), and most (92%) had an associated atrial septal aneurysm (defined as a displacement > 10 mm). The sizes of the largest defects and the distance between the defects are shown in table 2. No patient had pulmonary hypertension prior to the procedure.

Regarding the procedure, all cases were guided by transesophageal echocardiography (TEE) and fluoroscopy, and 3 of them by intracoronary ultrasound (ICUS). In most cases, a single closure device was used (66% of patients); however, in 4 cases, 2 devices were needed, which were implanted during the same procedure (simultaneous implantation). The most widely used devices were the Amplatzer Septal Occluder (AGA Medical, United States) and the Amplatzer Cribriform (AGA Medical, United States). In one procedure, the Figulla Flex device (FFO, Occlutech GmbH, Germany) was used, and in another, the Occlutech device (Occlutech International AB, Sweden). Figure 1 shows one of the procedures that required 2 devices and was fluoroscopy-, TEE-, and ICUS-guided.

Figure 1. A: fluoroscopic image of the closure of a multi-fenestrated atrial septal defect with 2 devices guided by fluoroscopy, transesophageal echocardiography, and intracoronary ultrasound. B: transesophageal echocardiography, mid-esophageal plane, showing the 2 implanted closure devices.

Transcatheter closure was successful in all patients with mASD, without intraoperative complications. Transthoracic echocardiography (TTE) was performed 24 hours after closure and, then, 6 months later. Acetylsalicylic acid monotherapy was prescribed at discharge and maintained for 3 months, except for the 2 patients who had a stroke.

At 6 months, 75% showed no residual shunt, while the remaining 25% showed a grade 1 shunt (minimal, without hemodynamic consequences). Most patients with right ventricular dilatation, (8 out of 9 patients) showed a reduction in the baseline right ventricular end-diastolic diameter after the procedure. There were no strokes at the follow-up.

Table 3 compares the characteristics and results of transcatheter closure in patients with a single ASD and with mASD. In our cohort, patients with mASD were significantly younger (42 vs 54 years; P = .011), with no statistically significant differences in sex distribution (50% vs 69%; P = .207). The mASD group had smaller defects (8 mm vs 16 mm in the single ASD group) and a higher prevalence of atrial septal aneurysm (91% vs 27%). In both groups, the most frequent indication for closure was right heart dilatation. No differences were observed in the choice of imaging modality during the procedure or in the mean size of the implanted device. However, patients with mASD more frequently required > 1 device (single device in 66% vs 96% in the single ASD group). There were no inter-group differences regarding complications or the presence of residual shunt during follow-up.

Table 3. Comparison of patients with transcatheter closure of single vs multi-fenestrated atrial septal defect

DISCUSSION

Transcatheter closure of ostium secundum ASD has become a safe and effective alternative in adult patients. Our study analyzed the results of transcatheter ASD closure in patients older than 18 years, highlighting the differences between single ASD and mASD.

At our center, transcatheter closure has proven to be safe and effective in patients with mASD. The results obtained indicate a high success rate associated with the procedure, with the absence of significant intraoperative complications and a good short- and mid-term safety profile.

A relevant finding is that patients with mASD were significantly younger than those with a single ASD, which could be explained by the earlier detection of these defects due to more evident symptoms, or by the presence of atrial septal aneurysm, which in our cohort was significantly more frequent in the mASD group. This data is consistent with the literature, which describes a strong association between atrial septal aneurysm and the presence of multiple defects.5

As expected, the use of multiple devices was more common in the mASD group than in the single ASD group. Although most cases were treated with a single device in patients with mASD, a considerable percentage (40%) required additional devices due to greater anatomical complexity. This finding highlights the importance of a thorough preoperative planning and the need to guide the intervention with TEE or ICUS. Although the TEE provides a wider field of view, the ICUS is particularly useful in certain situations, as it allows for a more precise visualization of the posteroinferior border of the atrial septum.6

The described complications associated with transcatheter ASD closure include arrhythmias, atrioventricular block, and device erosion. Device embolization is usually a consequence of inadequate size or incorrect placement, and its incidence rate is < 1%. In our cohort of patients, complications were a rare finding, with only 3 cases of device embolization and 1 of supraventricular arrhythmia being reported. In the literature, there are doubts on whether these complications are more common when implanting multiple devices; however, in our patients with mASD, 40% of whom needed > 1 device, no complications were observed.7

Most patients with mASD showed complete closure of the defect at 6 months (75%), and the remaining 25% had a minimal shunt without hemodynamic consequences. A high percentage of patients with right heart dilatation showed favorable right ventricular remodeling. Furthermore, the absence of strokes during the observation period indicates the effectiveness of the procedure in terms of secondary prevention in this subgroup of patients.

Limitations

Among the limitations of our study, the following stand out: first, those inherent to its observational and retrospective design, in addition to being single-centered. Furthermore, the number of patients with mASD is relatively small (n = 12), which reduces statistical power. The absence of a control group of patients with mASD treated conservatively or with surgical closure prevents direct comparisons on the relative benefits of each strategy. Prospective studies with a larger sample size and prolonged follow-up will be necessary to confirm our findings and optimize the management of these patients.

CONCLUSIONS

Although the transcatheter closure of mASD is a solid therapeutic option in selected patients, with results comparable to those observed in patients with a single ASD, the need for prospective and multicenter studies remains to confirm these findings and optimize the therapeutic strategy in this group of patients.

FUNDING

None declared.

ETHICAL CONSIDERATIONS

Informed consent was obtained from all patients for the use of their interventional procedure for research purposes. The authors confirm that procedures were performed in full compliance of the regulations of the Clinical and Ethical Research Committee, and of the Helsinki Declaration of the World Medical Association. The authors confirm that sex and gender variables have been taken into consideration according to the SAGER guidelines.

STATEMENT ON THE USE OF ARTIFICIAL INTELLIGENCE

Artificial intelligence has not been used for the development of this work.

AUTHORS’ CONTRIBUTIONS

L. Cerdán Ferreira and M. López Ramón contributed to data collection. L. Cerdán Ferreira performed the statistical analysis. G. Fuertes Ferre, J. Sánchez-Rubio Lezcano, and M. López Ramón contributed to result interpretation. L. Cerdán Ferreira and G. Fuertes Ferre wrote the article, which was later reviewed by G. Fuertes Ferre, J. Sánchez-Rubio Lezcano, and M. López Ramón.

CONFLICTS OF INTEREST

None declared.

REFERENCES