Iatrogenic Atrial Septal Defect After Percutaneous Mitral Valve Repair With the MitraClip System

Iatrogenic atrial septal defects in structural heart interventions: Opening the Pandora's box

In the modern era of structural heart interventions, the total number of transseptal procedures is growing exponentially, thus increasing the rate and need for management of iatrogenic atrial septal defects (iASDs). To date, there are no official guidelines on the assessment and management of iASDs, due to inconclusive evidence on whether patients benefit more from the percutaneous closure of iASD than from conservative management and vigorous follow-up. Despite the abundance of observational studies on iASDs, there is still a lack of randomized studies. Evidence so far show that percutaneous closure is no superior over conservative treatment in patients with iASDs, however, it has been demonstrated that patients with spontaneous closure of iASDs experience less heart failure (HF) hospitalizations. On the other hand, researchers have investigated the beneficial nature of interatrial shunt therapy in patients with HFpEF and, more recently, with HFrEF, due to the presumed hemodynamic benefits. Herein, we provide an updated review of relevant literature, focusing on iASD persistence rates, predicting factors for their persistence, and clinical outcomes of iASD persistence, to summarize available evidence and discuss future directions in the field.

Intracardiac ultrasound-guided transseptal puncture in horses: Outcome, follow-up, and perioperative anticoagulant treatment

BACKGROUND

Cardiac catheterizations in horses are mainly performed in the right heart, as access to the left heart traditionally requires an arterial approach. Transseptal puncture (TSP) has been adapted for horses but data on follow-up and closure of the iatrogenic atrial septal defect (iASD) are lacking.

HYPOTHESIS/OBJECTIVES

To perform TSP and assess postoperative complications and iASD closure over a minimum of 4 weeks.

ANIMALS

Eleven healthy adult horses.

METHODS

Transseptal puncture was performed under general anesthesia. Serum cardiac troponin I concentrations were measured before and after puncture. Weekly, iASD closure was monitored using transthoracic and intracardiac echocardiography. Relationship between activated clotting time and anti-factor Xa activity during postoperative enoxaparin treatment was assessed in vitro and in vivo.

RESULTS

Transseptal puncture was successfully achieved in all horses within a median duration of 22 (range, 10-104) minutes. Balloon dilatation of the puncture site for sheath advancement was needed in 4 horses. Atrial arrhythmias occurred in 9/11 horses, including atrial premature depolarizations (N = 1), atrial tachycardia (N = 5), and fibrillation (N = 3). Serum cardiac troponin I concentrations increased after TSP, but remained under the reference value in 10/11 horses. Median time to iASD closure was 14 (1-35) days. Activated clotting time correlated with anti-factor Xa activity in vitro but not in vivo.

CONCLUSIONS AND CLINICAL IMPORTANCE

Transseptal puncture was successfully performed in all horses. The technique was safe and spontaneous iASD closure occurred in all horses. Clinical application of TSP will allow characterization and treatment of left-sided arrhythmias in horses.

Advancements in MitraClip Intervention for Mitral Regurgitation: A Comprehensive Review and Comparative Analysis of Clinical Trials

This comprehensive review explores the evolution and clinical impact of MitraClip intervention in the management of mitral regurgitation. Mitral regurgitation results from dysfunction in the mitral valve (MV) apparatus. The MitraClip Clip Delivery System was approved by the Food and Drug Administration (FDA) in 2013. The discussion delves into the procedural foundation of MitraClip intervention, primarily based on Alfieri's technique of edge-to-edge leaflet approximation. As highlighted by key clinical trials, including Endovascular Valve Edge-to-Edge Repair (EVEREST) II Trial, Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients with Functional Mitral Regurgitation (COAPT) Trial, and Percutaneous Repair with the MitraClip Device for Severe Functional/Secondary Mitral Regurgitation (MITRA-FR) trial, the efficacy and safety of MitraClip were evaluated in comparison to surgical interventions and guideline-directed medical therapy. Notably, the COAPT demonstrated significant benefits in reducing all-cause mortality and heart failure hospitalization, while the MITRA-FR presented contrasting results, emphasizing the importance of patient selection. An analysis of the EVEREST II trial underscores MitraClip's potential to achieve comparable outcomes to surgical intervention, emphasizing its role in reducing mitral regurgitation and improving clinical status. However, limitations and complications, such as device-related issues and the potential impact on future MV surgery, are discussed. The study also explores the evolving landscape of MV interventions, reflecting advancements and the growing acceptance of MitraClip. In conclusion, the MitraClip device represents a significant advancement in the treatment of mitral regurgitation. The data presented highlights its promising results in terms of reduced hospitalization rates, improved in-hospital mortality, and enhanced quality of life for patients. However, challenges remain, and careful consideration of patient selection and underlying pathology is crucial in determining the optimal treatment approach. Ongoing research and clinical experience will continue to refine our understanding of MitraClip's role in the evolving landscape of MV interventions.

Treating Recurrent Tricuspid Regurgitation and Iatrogenic Atrial Septal Defect

Heterotopic caval valve implantation may be a reasonable option for alleviating symptoms in select high-risk patients with recurrent tricuspid regurgitation after failed interventional tricuspid valve repair. However, altered right atrial hemodynamic status should be considered in procedural planning to avoid potential right-left shunting in cases of septal defects. (Level of Difficulty: Advanced.).

Fate of iatrogenic atrial septal defects following mitral transcatheter edge-to-edge repair - a subanalysis of the MITHRAS trial

Persisting iatrogenic atrial septal defects (iASD) after transcatheter mitral edge-to-edge repair (M-TEER) are associated with impaired outcomes. We investigated the natural history of relevant iASDs with left-to-right shunting post-M-TEER, predictors of spontaneous closure of iASD between 1 and 6 months post-M-TEER, and outcomes (heart failure [HF] hospitalization) in patients with spontaneous closure versus those with persistent iASD 6 months post-M-TEER. Patients with a relevant iASD 1-month post-M-TEER, who were treated conservatively in the randomized controlled MITHRAS trial, underwent clinical follow-up including transesophageal echocardiography 6 months post-M-TEER. Overall, 36 patients (median 77 [interquartile range 65-81] years; 36% women) completed the 6-months follow-up. Six (17%) patients had a spontaneous closure of the iASD. The eccentricity index of the iASD 1-month after M-TEER was the strongest predictor for spontaneous closure (Odds ratio 3.78; 95% confidence interval 1.26-11.33, p = 0.01) and an eccentricity index of < 1.9 provided a sensitivity of 77% at a specificity of 83% for iASD persistence (Area under the curve 0.83, p < 0.001) within 6-months post M-TEER.At follow-up, a numerical difference in the endpoint of HF hospitalization between the spontaneous closure and the residual shunt group (0% vs. 20%, p = 0.25) was observed. The eccentricity of the iASD was the strongest predictor for spontaneous closure at 1-months and an eccentricity index of < 1.9 is associated with a high persistence rate for 6 month after M-TEER. Clinical Trial Registration ClinicalTrials.gov https://clinicaltrials.gov/ct2/show/NCT03024268 Identifier: NCT03024268. a (red) is reflecting the mayor lengthwise dimension and b (blue) the mayor oblique dimension. The eccentricity index is calculated by dividing a through b. (Open circle) is depicting an example for a round iASD and (Open rhombus) an example for an eccentric iASD 1 month after M-TEER.

Impact of Persistent Iatrogenic Atrial Septal Defect following MitraClip

BACKGROUND

Prior studies have reported conflicting results of persistent iatrogenic atrial septal defect (iASD) and its impact following a transcatheter edge-to-edge repair (TEER) procedure. This study aims to evaluate the incidence of iASD and its clinical and hemodynamic impact after a TEER.

METHODS

Consecutive patients who underwent a TEER procedure from June 2014 to September 2020 at the Mayo Clinic were identified. The presence of iASD was retrospectively identified on post-procedure transthoracic echocardiography (TTE) to group patients into an iASD+ group and an iASD- group for comparison of prognosis and cardiac function.

RESULTS

A total of 316 patients were included; the mean age was 79.1 ± 9.1 years, and 67.7% were male. Persistent iASD was diagnosed in 108 (34.2%) patients. There was no difference concerning all-cause mortality, heart failure hospitalization, and stroke/TIA between groups at follow-up (median follow-up of 9 months). Post-procedure TTE demonstrated no differences regarding right ventricle (RV) and left ventricle (LV) dimensions and function, including TAPSE (15.2 ± 4.6 vs. 15.4 ± 5.5 mm, p = 0.875), and LV ejection fraction (51.1 ± 14.0% vs. 51.3 ± 13.9%, p = 0.933). However, patients with iASD had higher RV systolic pressure (48.7 ± 14.4 vs. 45.5 ± 14.5 mmHg, p = 0.042) compared with patients without iASD.

CONCLUSION

Notwithstanding higher RV pressures, patients with persistent iASD had no hemodynamic compromise and an equal prognosis compared with those without a residual atrial defect after a TEER procedure. These findings support the mid-term safety of procedures in which an interatrial defect needs to be created and would argue against the need for interventional closure.

Iatrogenic Atrial Septal Defect Requiring Transcatheter Closure Following Transcatheter Mitral Valve Repair

BACKGROUND

Transcatheter mitral valve repair with the MitraClip system has been established in selected high-risk patients. The MitraClip procedure results in a relatively large iatrogenic atrial septal defect (iASD). This study aimed to investigate the prevalence and clinical course of iASD requiring transcatheter closure following the MitraClip procedure.

METHODS AND RESULTS

This study was conducted at all 59 institutions that perform transcatheter mitral valve repair with the MitraClip system in Japan. The data of patients on whom transcatheter iASD closure was performed were collected. Of the 2,722 patients who underwent the MitraClip procedure, 30 (1%) required transcatheter iASD closure. The maximum iASD size was 9±4 mm (range, 3-18 mm). The common clinical course of transcatheter iASD closure was hypoxemia with right-to-left shunt or right-sided heart failure with left-to-right shunt. Of the 30 patients, 22 (73%) required transcatheter closure within 24 h following the MitraClip procedure, including 12 with hypoxemia and 5 with right-sided heart failure complicated with cardiogenic shock. Of the 5 patients, 2 required mechanical circulatory support devices. Twenty-one patients immediately underwent transcatheter iASD closure, and hemodynamic deteriorations were resolved; however, 1 patient died without having undergone transcatheter closure.

CONCLUSIONS

Transcatheter iASD closure was required in 1% of patients who underwent the MitraClip procedure. Many of these patients immediately underwent transcatheter iASD closure because of hypoxemia with right-to-left shunt or right-sided heart failure with left-to-right shunt.

Iatrogenic atrial septal defect persistence after percutaneous mitral valve repair: a meta-analysis

BACKGROUND

Percutaneous mitral valve repair (PMVR) requires a puncture of the atrial septum, resulting in iatrogenic atrial septal defect (iASD), which usually causes a transient left-to-right shunt. However, the influencing risk factors for iASD persistence and functional consequences are not fully understood. This meta-analysis aimed to summarise available data on the persistence of iASD following PMVR.

METHODS

The authors conducted a literature search in PubMed/MEDLINE and EMBASE databases to identify studies investigating iASD persistence in PMVR patients.

RESULTS

Six observational studies (n = 361) met inclusion criteria for the final analysis. Prevalence of persistent iASD was documented with 28% after 12 months follow-up. iASD size increased over time with a diameter of 5.3 ± 0.76 mm after one month and 6.5 ± 0.21 mm after 12 months. Possible predictors of iASD persistence after PMVR appeared to be pre-existing AF (RR 1.24; p = .03), residual mitral regurgitation > II° (RR 2.06; p = .03) and prolonged fluoroscopic time (RR 8.27; p = .01). Patients with iASD persistence had a higher risk for development of right heart overload regarding the increased area of the right atrium (MD 5.24; p = .004) and enlarged diameter of the right ventricle (MD 3.33; p < .0001). Rehospitalization was more frequently reported in iASD patients (RR 9.52; p = .004).

CONCLUSIONS

This meta-analysis proved iASD persistence in 28% of PMVR after 12 months follow-up with a higher risk for right heart volume overload and more frequent rehospitalization compared to patients without iASD persistence. Since percutaneous catheter-based treatments with transseptal approaches are rising, further evidence about the hemodynamic impact of persistent iASD is warranted.

Transseptal puncture: Review of anatomy, techniques, complications and challenges, a critical view

Transseptal puncture (TSP) was initially described to gain access to the left heart for hemodynamic assessment. Continuous evolution from its origins allows interventionists to perform a myriad of procedures that otherwise would be impossible to accomplish. In the recent years, the number of procedures in cardiology that require TSP has grown exponentially. Namely, transcatheter mitral valve repair and replacement, pulmonary vein isolation and left atrium appendage occlusion. In skilled hands, it is a safe and straightforward procedure; however, a lack of knowledge of the materials, anatomy of the interatrial septum and the technique can be met with life-threatening complications. Therefore, it is imperative that interventional cardiologists master this technique to successfully overcome these obstacles and ensure clinical outcomes in patients requiring TSP. The purpose of the following review is to critically analyze the available evidence regarding TSP, provide a step-by-step approach to the technique, the available materials and tips and tricks to overcome difficulties and manage complications.

Iatrogenic Atrial Septal Defects Following Transcatheter Mitral Valve Repair and Implications of Interventional Closure

OBJECTIVES

The authors investigated whether iatrogenic atrial septal defect (iASD) closure post-transcatheter mitral valve edge-to-edge repair (TMVR) is superior to conservative therapy (CT) and whether outcomes (death/heart failure [HF] hospitalization) differ between patients with and without an iASD post-TMVR.

BACKGROUND

Transseptal access for TMVR can create an iASD, which is associated with impaired outcomes. Controversially, the creation of an iASD in HF has been linked to improved hemodynamics.

METHODS

80 patients with an iASD and relevant left-to-right shunting (Qp:Qs ≥1.3) 30 days following TMVR were randomized to CT or interventional closure of the iASD (MITHRAS [Closure of Iatrogenic Atrial Septal Defect Following Transcatheter Mitral Valve Repair] cohort), and 235 patients without an iASD served as a comparative cohort.

RESULTS

All patients of the MITHRAS cohort (mean age 77 ± 9 years, 39% women) received their allocated treatment, and follow-up was completed for all MITHRAS and comparative cohort (mean age 77 ± 8 years, 47% women) patients. Twelve months post-TMVR, there was no significant difference in the combined endpoint of death or HF hospitalization within the MITHRAS cohort (iASD closure: 35% vs CT 50%; P = 0.26). The combined endpoint was more frequent among patients within the MITHRAS cohort as opposed to the comparative cohort (43% vs 17%; P < 0.0001), primarily driven by a higher rate of HF hospitalization (34% vs 8%; P = 0.004).

CONCLUSIONS

In this randomized controlled trial, interventional closure of a relevant iASD 1 month after TMVR did not result in improved clinical outcomes at 12 months post-TMVR. Patients with an iASD are at higher risk for HF hospitalization independent of iASD management and warrant close follow-up. (Closure of Iatrogenic Atrial Septal Defect Following Transcatheter Mitral Valve Repair [MITHRAS]; NCT03024268).

Incidence, persistence, and clinical relevance of iatrogenic atrial septal defects after percutaneous left atrial appendage occlusion

OBJECTIVE

To investigate the rate and clinical impact of a persisting iatrogenic atrial septal defect (iASD) after percutaneous left atrial appendage occlusion (LAAO).

BACKGROUND

Percutaneous LAAO is an alternative to oral anticoagulation (OAC) for the prevention of ischemic stroke and systemic embolism in patients with atrial fibrillation (AF). Data regarding incidence and persistence of iASD after LAAO procedures and its clinical relevance is scarce.

METHODS

We retrospectively analyzed 144 patients that underwent LAAO at our center between 2009 and 2020 who had at least one follow-up including transesophageal echocardiography (TEE). Baseline clinical, procedural data and echocardiographic characteristics in patients with and without evidence of an iASD were compared. We furthermore determined the rate of iASD persistence over time and evaluated outcomes of patients with and without spontaneous iASD closure.

RESULTS

After a median of 92 days (IQR 75-108 days) after LAAO, 50 patients (50/144, 34.7%) showed evidence of an iASD. Patients with iASD had higher CHADS-VASc-scores (4.9±1.5 vs 4.2±1.2, p = 0.03), larger left atrial volumes (80.5±30.5 ml vs 67.1±19.7 ml, p = 0.01) and were more likely to have relevant mitral regurgitation (≥° II) (46.0% vs 12.3%, p = 0.001). LAAO procedures took longer (50.1±24.3 vs 41.1±17.8 min, p = 0.06) in patients with a persisting iASD. Furthermore, larger device sizes were implanted (24.3±3.4 mm vs 22.1±2.8 mm, p = 0.03). The presence of an iASD had no impact on RV dysfunction, thromboembolism or mortality. Spontaneous closure of an iASD was documented in 52.0% (26/50). Hereby, similar risk factors were identified for the persistence of an iASD in follow-up.

Prevalence of iatrogenic atrial septal defects (iASD) after mitral valve (MV) transcatheter edge-to-edge repair (TEER) in the long-term follow-up

OBJECTIVES

To investigate prevalence of iatrogenic atrial septal defects (iASDs) after mitral valve (MV) transcatheter edge-to-edge repair (TEER) with the MitraClip in the long-term follow-up.

BACKGROUND

MV TEER requires transseptal puncture using a large 22 F sheath. Prevalence, impact and haemodynamic effects of these iASDs remain unknown in the long-term follow-up.

METHODS

This prospective study enrolled patients who had undergone first-time TEER at our university hospital between January 2017 and June 2018 for a clinical long-term follow-up study. Prevalence of iASD was investigated 12 months post-TEER using transoesophageal echocardiography (TEE). Study protocol further consisted of transthoracic echocardiography (TTE) and exercise testing. Incidence of all-cause death was compared 12 months post-TEE follow-up. This study was approved by local ethics committee.

RESULTS

48 patients participated in clinical follow-up examinations. Median time between TEER and clinical follow-up examination (TEE, TTE, exercise testing) was 19.5 (IQR: 7.0) months after TEER. Persistent iASD was found in 41.7% of patients. TEER was found to be equally effective in reducing MR and clinical symptoms in both groups at baseline as well as follow-up. Procedural fluoroscopy and device times were significantly longer in the iASD group. MR reduction and functional status (New York Heart Association Class, 6 Minute Walking Test distance) were similar in both groups. Nevertheless, a significant decrease in systolic pulmonary artery pressure (sPAP) and significantly smaller atrial diameters were observed in patients with iASD at follow-up.

CONCLUSION

Prevalence of iASDs after TEER in long-term follow-up was about 41%. Although a significant reduction of sPAP and better left atrial reverse remodelling were accomplished in patients with iASD, clinical impact appears low. Manipulation at the atrial septum might play a key role in creating persisting iASD.

Complications Following MitraClip Implantation

Purpose of Review

To provide a detailed overview of complications associated with MitraClip therapy and its development over time with the aim to alert physicians for early recognition of complications and to offer treatment strategies for each complication, if possible.

Recent Findings

The MitraClip system (MC) is the leading transcatheter technique to treat mitral regurgitation (MR) and has been established as a safe procedure with very low adverse event rates compared to mitral surgery at intermediate to high risk or in secondary MR. Lately, the fourth MC generation has been launched with novel technical features to facilitate device handling, decrease complication rates, and allow the treatment of even complex lesions.

Summary

Although the complication rate is low, adverse events are associated with increased morbidity and mortality. The most common complications are bleeding, acute kidney failure, procedure-induced mitral stenosis, and an iatrogenic atrial septal defect with unknown clinical impact.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11886-021-01553-9.

Biventricular Physiology of Iatrogenic Atrial Septal Defects Following Transcatheter Mitral Valve Edge-to-Edge Repair

OBJECTIVES

The study sought to assess the acute hemodynamic effects of iatrogenic atrial septal defect (iASD) closure following transcatheter mitral valve edge-to-edge repair (TMVR).

BACKGROUND

The potential hemodynamic and clinical consequences of an iASD following TMVR are currently subject to controversial debates.

METHODS

In 21 patients with relevant left-to-right shunt flow (50% [IQR: 38% to 60%] of systemic perfusion volume) across an iASD following TMVR, interventional closure was performed with recordings of left ventricular (LV) and right ventricular (RV) pressure-volume loops during iASD occlusion.

RESULTS

iASD occlusion led to a volume shift from the RV (RV end-diastolic volume index: pre 102 [IQR: 80 to 120] ml/m², post 92 [IQR: 70 to 111] ml/m²; p < 0.001) to the LV (LV end-diastolic volume index: pre 91 [IQR: 74 to 124] ml/m², post 97 [IQR: 77 to 127] ml/m²; p < 0.001) with reduced RV (3.49 [IQR: 2.07 to 3.58] l/min/m² vs. 2.68 [IQR: 2.07 to 3.58] l/min/m²; p < 0.001) but increased LV cardiac index (2.25 [IQR: 1.80 to 3.28] l/min/m² vs. 2.77 [IQR: 1.90 to 3.34] l/min/m²; p = 0.039). Although RV end-diastolic pressure decreased (pre 5.0 [IQR: 4.0 to 8.5] mm Hg, post 4.5 [IQR: 3.0 to 8.3] mm Hg; p = 0.024), LV end-diastolic pressure remained unchanged (pre 11.0 [IQR: 9.5 to 14.0] mm Hg, post 13.0 [IQR: 9.0 to 15.5] mm Hg; p = 0.142). LV transmural pressure increased (7.0 [IQR: 4.0 to 11.0] mm Hg vs. 11.0 [IQR: 7.0 to 15.0] mm Hg; p = 0.001) and LV eccentricity index decreased (p < 0.001). The change in LV transmural pressure correlated significantly with the change in LV-to-RV end-diastolic volume ratio (r = 0.674; p = 0.018). Right heart failure symptoms declined at 1-month follow-up (71% vs. 35%; p = 0.003) as did New York Heart Association functional class (≥III: 48% vs. 25%; p < 0.001).

CONCLUSIONS

iASD closure following TMVR leads to a volume shift from the RV to the LV with reduced pulmonary but increased systemic cardiac index and with favorable biventricular interaction at maintained LV filling pressure, resulting in a decline in heart failure symptoms at 1-month follow-up.

Incidence and clinical relevance of persistent iatrogenic atrial septal defect after percutaneous mitral valve repair

Percutaneous mitral valve repair (PMVR) requires transseptal puncture and results in iatrogenic atrial septal defect (iASD). The impact of persistent iASD was previously investigated. However, data were diverse and inconclusive. 53 patients who underwent MITRACLIP were retrospectively included. Based on the presence of iASD in transesophageal echocardiography (TEE) after 6 months, patients were divided in two groups (iASD group vs. non-iASD group). Impact of iASD on outcome at 6 months and at two years was evaluated. Persistent iASD was detected in 62% of patients. Independent predictors for persistent iASD were female gender and reduced left ventricular ejection fraction. At 6-month follow-up, there was no difference in reduction of NYHA class (ΔNYHA = 1.3 ± 1 in iASD group vs. 0.9 ± 1 in non-iASD group, p = 0.171). There was a significant difference in right ventricular end diastolic diameter (RVEDd) (42 ± 8 mm in iASD-group vs. 39 ± 4 mm in non-iASD group, p = 0.047). However, right ventricular systolic function (TAPSE) (14 ± 7 mm in iASD group vs. 16 ± 8 mm in non-iASD group, p = 0.176) and right ventricular systolic pressure (RVSP) (40 ± 12 mmHg in iASD group vs. 35 ± 10 mmHg in non-iASD group, p = 0.136) were still comparable between both groups. At 2 years follow-up, there was no significant difference regarding rate of rehospitalization (24% vs 15%, p = 0.425) or mortality (12% vs 10%, p = 0.941) between both groups. Incidence of persistent iASD after MITRACLIP is markedly high. Despite the increase in right ventricular diameter in patients with persistent iASD, these patients were not clinically compromised compared to patients without persistent iASD.

Devices for transcatheter mitral valve repair: current technology and a glimpse into the future

Introduction: Due to a large unmet need for the treatment of mitral regurgitation, transcatheter mitral valve repair devices have emerged in the last decade as an alternative therapeutic option. Given the complexity of this disease, several device systems for transcatheter mitral valve repair have been developed and are categorized according to its mechanism of action; each device has advantages and disadvantages for certain clinical and pathophysiologic characteristics, and in order to improve outcomes, proper patient selection among other key points are fundamental.Areas covered: The purpose of this article is to review the current state-of-the-art technologies available for transcatheter mitral valve repair, patient suitability, outcomes, and future perspectives.Expert opinion: Transcatheter therapy for mitral regurgitation improves outcomes and pushes the boundaries of biomedical technology while maintaining scientific rigor for device development. Surgical and percutaneous procedures should be viewed as complements to treat a wider spectrum of patients affected by this entity. Future directions from multidisciplinary innovation and cooperation will consolidate this therapeutic option.

Iatrogenic atrial septal defect after percutaneous left atrial appendage closure: a single-center study

There is conflicting evidence regarding the significance of iatrogenic atrial septal defects (iASDs) after transseptal puncture during percutaneous cardiac interventions. To study the clinical outcome of iASD after percutaneous left atrial appendage occlusion (LAAo). Single-center, retrospective study of 70 consecutive patients who underwent percutaneous LAAo between May 2010 and August 2017, and subsequent transesophageal echocardiography (TEE) at 1 month. The sample population was divided into two groups: A (with iASD, 22 (37%) patients) and B (no iASD, 44 (63%) patients). Procedures were guided either by TEE (36 patients (54%)) or intracardiac echocardiography (ICE) from the left atrium (30 patients (46%)). The primary end point was presence of iASD at 1 month, and secondary end points included mortality, hospital admission due to heart failure (HF), and right atrium (RA) size during follow-up. 70 patients were included in this study and the prevalence of iASD at 1 month was 37%. The use of ICE was associated with iASD (adjusted odds ratio, 3.79; 95% CI 1.27-11.34). The presence of iASD was not associated with adverse events (mortality, 15.4% vs 20.5%; P = 0.60; HF hospitalizations, 7.7% vs 13.6%, P = 0.45; and RA area, 24.8 ± 7.0 cm² vs 22.2 ± 6.8 cm², P = 0.192). At 1-month follow-up after LAAo, iASD was present in one third of patients, but was not associated with clinical outcomes. The use of ICE was associated with a higher risk of short-term iASD.

Management of Iatrogenic Atrial Septal Defects in the Era of Large-Bore Transcatheter Mitral Valve Therapies

Several case reports described acute and subacute decompensations that were reversed after percutaneous interatrial septal defect (ASD) closure. At least 30% of patients post MitraClip will continue to have a persistent ASD at 1 year. Few retrospective studies described various echocardiographic associations with persistent ASD but there is no conclusive evidence that it is the cause of a poor outcome. Conclusion: At this time routine closure of ASD post MitraClip is not recommended unless there is hemodynamic decompensation that cannot be explained by other factors.

Pulmonary artery pressures and outcomes after MitraClip

AIMS

We evaluated the impact of MitraClip on systolic pulmonary artery pressure (sPAP) and the effects of baseline sPAP on outcomes.

METHODS AND RESULTS

In a cohort of patients who underwent MitraClip implantation, three groups were defined according to pre-procedure sPAP levels. Clinical and echocardiographic data were compared. The study included 177 patients: 59 had severe pulmonary hypertension (PHT), 96 had mild to moderate PHT, and 22 had no PHT. In patients with pre-existing severe PHT, sPAP was reduced from 70.8 ± 9.2 to 56.8 ± 13.7 mmHg (P < 0.001), sPAP remained unchanged in patients with mild to moderate PHT but was significantly increased from 30.8 ± 4.3 to 38.6 ± 8.3 mmHg in the no-PHT group (P < 0.001). Improvement of sPAP was observed in 77% of severe PHT group, while worsening of sPAP was more common among patients with no-PHT [57% compared with 33% among the mild to moderate PHT and 7% in the severe PHT group, respectively, (P < 0.001)]. One year survival was similar among the study groups.

CONCLUSIONS

MitraClip decreases PHT among patients with severe PHT. A concerning finding is that most patients with no-PHT increase their sPAP.

Iatrogenic atrial septal defect caused by repeated catheter ablation

Iatrogenic atrial septal defect is an issue after percutaneous interventions for structural heart disease. A 63-year-old man, who had previously received 5 catheter ablations for paroxysmal atrial fibrillation, was found to have an iatrogenic atrial septal defect that persisted after the fourth intervention. Approximately 4 years later, he suffered exertional dyspnea. Pulmonary hypertension was caused by a left-to-right shunt via a large iatrogenic atrial septal defect. We performed surgical closure and the symptom improved. The timing of treatment for persistent iatrogenic atrial septal defect is difficult to determine, but preferable before the appearance of right ventricular dysfunction or embolism.

Mitral regurgitation: a contemporary review of percutaneous mitral valve repair and role of periprocedural imaging

PURPOSE OF REVIEW

This article aims to review recent landmark clinical trials that have resulted in a paradigm shift in the management of patients with mitral regurgitation. This article additionally highlights the instrumental role that structural heart disease (SHD) imaging plays in evaluation of mitral regurgitation and determining candidacy for transcatheter mitral valve repair (TMVr), in addition to the procedural guidance and detection of complications.

RECENT FINDINGS

Edge-to-edge TMVr with the MitraClip device (Abbott Vascular, Santa Clara, California) was initially studied and subsequently approved by the US Food and Drug Administration (FDA) for treatment of primary mitral regurgitation in 2013. After the publication of a landmark clinical trial in 2018, the indications have been expanded and FDA has subsequently, in 2019, approved TMVr for patients with functional mitral regurgitation. This has been paralleled by advances in cardiac imaging with more emphasis on the role of SHD imagers as a part of the heart team.

SUMMARY

TMVr has revolutionized the management of mitral regurgitation and relies heavily on SHD imaging to ensure optimal outcomes.

Left atrial pressure is associated with iatrogenic atrial septal defect after mitral valve clip

OBJECTIVES

Mitral valve (MV) clip procedure requires interatrial trans-septal puncture to access the left atrium (LA). Iatrogenic atrial septal defect (iASD) is not uncommon and may remain for a while. However, haemodynamic and echocardiographic determinants of persistent iASD are not well investigated. We sought to find haemodynamic and echocardiographic determinants of iASD after MV clip.

METHODS

A total of 131 patients with grades 3 to 4+ mitral regurgitation who underwent MitraClip and completed invasive haemodynamic measurement, baseline, 1 month and approximately 12 months of transthoracic echocardiography (TTE) follow-up were retrospectively reviewed.

RESULTS

TTE at 1 month showed persistent iASD in 57% (1M-iASD). Mean LA pressure after clip was significantly higher in patients with 1M-iASD than patients without 1M-iASD (17±6 mm Hg vs 15±5 mm Hg, p=0.01). Among patients with 1M-iASD, 24 patients (35%) had persistent iASD at 12 months (12M-iASD). Mean LA pressure after clip was significantly higher in patients with 12M-iASD than patients without 12M-iASD (19±6 mm Hg vs 16±6 mm Hg, p=0.04). Patients with 12M-iASD did not significantly differ from patients without 12M-iASD in terms of right heart enlargement, estimated systolic pulmonary artery pressure, New York Heart Association functional class and brain natriuretic peptide at 12 months. Logistic regression analysis, however, showed that mean LA pressure after clip was significantly associated with persistent iASD at 12 months in patients with 1M-iASD even after adjustment for cardiac index after clip and the prevalence of mitral regurgitation ≥3+ at 12 months (OR 1.10 per 1 mm Hg, 95% CI 1.01 to 1.21, p=0.04).

CONCLUSIONS

Elevated LA pressure after MV clip was associated with persistent iASD.

Secondary right heart failure due to haemodynamically relevant iatrogenic atrial septal defect: does the sequence of structural interventions sometimes matter? A case report

Background

Edge-to-edge mitral valve repair is a common procedure for treating severe symptomatic mitral valve regurgitation in patients not eligible for surgery.

Case summary

After necessary transseptal puncture during the MitraClip procedure, an iatrogenic atrial septal defect (iASD) routinely remains and closes spontaneously in most cases. We present a case in which this shunt persisted due to increased left heart pressure, causing repeated rehospitalization, and ultimately requiring interventional closure: after successful transcatheter edge-to-edge repair of severe, symptomatic mitral regurgitation, the iASD persisted presumably due to underestimated paradoxical low-flow, low-gradient aortic valve stenosis. Despite transcatheter aortic valve implantation, the iASD became haemodynamically relevant requiring successful interventional iASD closure in the end after a long period of rehospitalizations. We evaluated the symptoms, haemodynamic, and functional characteristics of the patient using several diagnostic tools, as well as the comorbidities of the patient, in terms of their potential to favour the persistence and haemodynamic relevance of iASDs.

Discussion

The combination of sophisticated diagnostic tools, such as cardiac magnetic resonance imaging and transoesophageal echocardiography (TOE), physical examination, and symptoms can be used to identify patients vulnerable to the development of a haemodynamic-relevant iASD that will need early interventional treatment.

Iatrogenic atrial septal defect post mitral valve in valve implantation

A 75 year-old female with symptomatic severe mitral regurgitation of a bio-prosthetic valve secondary to valve leaflet perforation due to endocarditis underwent a mitral valve in valve replacement in an existing Hancock 27 mm valve using a trans-femoral/trans-septal approach. The procedure was complicated by an iatrogenic atrial septal defect post trans-septal puncture causing a severe right-to-left shunt due, possibly, to the combination of severe pulmonary hypertension and moderate tricuspid regurgitation the patient had suffered from at base line. Once the sheath was removed an immediate desaturation was observed which required emergent closure with an AMPLATZER ASD Occluder device (St. Jude Medical/Abbott Structural, St. Paul, Minnesota, MN). This stabilized the patient and returned her blood oxygen levels to normal. The case brings forth a rare but important complication that may occur during trans-septal procedures especially when using large sheaths. It emphasizes the importance of proper echocardiographic and hemodynamic evaluation prior to such procedures in order to be prepared for such complications.