One Year Incidence of Iatrogenic Atrial Septal Defect After Cryoballoon Ablation for Atrial Fibrillation

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.

Reduction in atrial and pulmonary vein stretch as a therapeutic target for prevention of atrial fibrillation

Atrial fibrillation (AF) is a common cardiac arrhythmia that is associated with increased mortality. Heart failure, hypertension, valvular disease, and obstructive sleep apnea are risk factors for incident AF. A common characteristic of these diseases is that they increase atrial wall stretch. Multiple experimental studies confirm a proarrhythmic effect of atrial stretch. Conversely, a reduction in stretch is antiarrhythmic. A therapeutic target for AF, therefore, lies in local reduction of atrial stretch. This review focuses on atrial stretch and its clinical associations in patients with AF and its downstream effects on electrophysiology. We discuss the possible application of targeted atrial stretch reduction in AF prevention. We conclude that a reduction in local atrial stretch should be considered an essential element in rhythm control.

Iatrogenic atrial septal defects after transseptal puncture for percutaneous left atrial appendage occlusion and their hemodynamic effects

BACKGROUND

Percutaneous left atrial appendage occlusion (LAAO) requires puncture of the interatrial septum. The immediate hemodynamic effects of iatrogenic atrial septal defects (iASD) after LAAO have not been examined so far. We aimed at evaluating these effects through invasive measurements of pressure and oxygen saturation. Moreover, we assessed the incidence of persistent iASD at three months.

METHODS

Forty-eight patients scheduled for percutaneous LAAO were prospectively included in the study. Pressure and oxygen saturation were measured (1) in the right atrium (RA) before transseptal puncture, (2) in the left atrium (LA) through the transseptal sheath after transseptal puncture, (3) in the LA after removal of introducer sheath, and (4) in the RA after removal of introducer sheath. Transesophageal echocardiography was performed at three months to detect iASD.

RESULTS

Pressure in the RA increased significantly after removing the introducer sheath (P = 0.034), whereas no difference was found in oxygen saturation in the RA (P = 0.623). Pressure measurement in the LA showed no significant difference after removing the introducer sheath (P = 0.718). Oxygen saturation in the LA also showed no significant difference (P = 0.129). Follow-up transesophageal echocardiogram at 3 months revealed a persistent iASD in 4 patients (8.5 %).

CONCLUSIONS

Our study suggests that iASD after percutaneous LAAO does not result in significant shunts directly after the procedure, although a significant increase of mean right atrial pressure can be observed. Persistent iASDs after percutaneous LAAO seem to be relatively rare at three months.

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.

The influence of iatrogenic atrial septal defect on the prognosis of patients with atrial fibrillation between cryoablation and radiofrequency ablation

OBJECTIVE

The present study was to compare the incidence of septal defect (SD) in patients with atrial fibrillation (AF) who received radiofrequency ablation or cryoablation.

METHODS

A total of 293 AF patients were performed with radiofrequency ablation and cryoablation. Cardiac ultrasonography was performed to calculate left atrial diameter (LAD), left atrial ejection fraction (LAEF%), strain rate (SR), left ventricular systolic (SRs), left ventricular diastolic (SRe), and left atrial systole (SRa) before surgery, 3 months and 1 year after surgery. The patients were followed up to observe statin and angiotensin-converting enzyme inhibitor (ACEI)/angiotensin receptor blocker (ARB) medication, AF recurrence, 6-min walk test, stroke, any symptoms caused by arrhythmia, and re-hospitalization.

RESULTS

The levels of LAD and SD were higher, while SRe and SRa were lower in the cryoablation group in the comparison with the radiofrequency ablation group after surgery (P<0.05). LAEF was lower in the cryoablation group than the radiofrequency ablation group after 3 months (P<0.05). After 1-year follow-up, no right-to-left shunt occurred in all patients with SD. The AF recurrence rate in SD group was higher than that in the normal group (P<0.05). The use of statin and the application of ACEI/ARB were protective factors, whereas hypertension, LAD, left atrial operation time, and surgical plan were risk factors.

CONCLUSION

SD affects left atrial function and increases the risk of AF recurrence. Hypertension, LAD, and left atrial operation time are risk factors for SD, whereas statin and ACEI/ARB drugs can reduce SD.

Thromboembolic Events Following Atrial Fibrillation Cardioversion and Ablation: What's the Culprit?

Stroke is a rare but possible complication after atrial fibrillation (AF) ablation. However, its etiopathogenesis is far from being completely characterized. Here we report a case of stroke, with recurrent peripheral embolism after AF ablation procedure. In our patient, an in situ femoral vein thrombosis and iatrogenic atrial septal defect were simultaneously detected. A comprehensive review of multiple pathophysiological mechanisms of stroke in this context is provided. The case underlines the importance of a global evaluation of patients undergoing AF ablation.

Prospective evaluation of iatrogenic atrial septal defect after cryoballoon or radiofrequency catheter ablation of atrial fibrillation-"EVITA" study

PURPOSE

Iatrogenic atrial septal defect (IASD) after catheter ablation (CA) for atrial fibrillation (AF) due to transseptal puncture (TSP) can occur. The aim of this prospective study was to describe the incidence of IASD and to detect any cerebrovascular accident (CVA) after radiofrequency (RF) and cryoballoon (CB) CA.

METHODS

Between July 2014 and September 2016, 94 patients (pts) (RF; 48, CB; 46, 30 (31.9%) women, mean age = 60 ± 9.7 years) with paroxysmal AF were enrolled who underwent CA procedure for the first time. During RF ablation a single (n = 30, 62.5%) or double (n = 18, 37.5%) TSP was performed. Transoesophageal echocardiography before the procedure and at the 3-month and 12-month follow-up (FU) was accomplished. During the FU period, we evaluated the occurrence of any postprocedural CVA.

RESULTS

At the 3-month FU, IASD was detected in 17/94 (18.1%) pts; in 9/48 (18.8%) pts in the RF while in 8/46 (17.4%) pts in the CB group (p = 0.866), all of them with left-to-right shunt. In the RF group, 6/30 (20%) pts with a single TSP while 3/18 (16.7%) pts in the double TSP group had IASD (p = 0.780). 14/17 (82.4%) IASDs showed high spontaneous closure rate at the 12-month FU. None of the pts died or suffered from CVA.

CONCLUSION

Persistent IASD can occur rather frequently following AF CA. No significant difference was observed between the RF and CB techniques concerning the presence of IASD at 3-month. IASDs showed a high spontaneous closure rate. No cerebral thromboembolic event was observed in the 12-month FU period.

Percutaneous Closure of Persistent Atrial Septal Defects After Pulmonary Vein Isolation

Pulmonary vein isolation (PVI) with radiofrequency or cryoballoon ablation to treat atrial fibrillation requires trans-septal puncture. This creates a small iatrogenic atrial septal defect (iASD). In most patients, the defect spontaneously closes after 3-6 months. However, persistent iASDs can cause hemodynamic changes and adverse consequences from inter-atrial shunting. Persistent post PVI iASDs that are clinically significant can be closed percutaneously. This diagnosis should be considered in patients with worsening dyspnea or fatigue after PVI. We present a case of post PVI iASDs causing immediate or late onset hemodynamic changes and clinical symptoms, which improved after ASD closure. We provide a review of previously reported cases and literature on post PVI ASD prevalence, risk factors and outcomes after ASD closure.

The influence of iatrogenic interatrial septum leaks after left atrial appendage closure on cardiac function test results

AIM

Left atrial appendage occlusion (LAAO) is a technique for preventing thromboembolism in patients with atrial fibrillation and a high risk of irreversible bleeding. In some patients, a spontaneous iatrogenic transseptal leak (ITL) remains after LAAO. The aim of this study was to assess the correlation between ITL incidence and the results of cardiac function tests in patients who underwent LAAO.

METHODS AND RESULTS

LAOO was performed in 62 consecutive patients using the Amplatzer Amulet. Before and 3 months after LAA occlusion, the 6-min walking distance (6MWD) test was performed in all patients and oxygen consumption assessment (VO_2max ) was performed in 32. All patients had transesophageal echocardiography before and 3 months after LAAO to assess ITL incidence. The patients were divided according to the presence and absence of ITL and the subgroup of patients with heart failure (HF) were further analyzed. In patients with HF and ITL, an increased VO_2max (12.8 ± 5.2 vs 15.3 ± 4.7; P < 0.05) and 6MWD (350.1 ± 77.4 vs 414.3 ± 70.6; P < 0.05) was observed after the procedure comparing to the results before the procedure. The 6MWD was also significantly higher in the patients with transseptal leaks in comparison to those without (P < 0.0001).

CONCLUSION

The presence of transseptal leaks after LAAO does not influence overall cardiac function test results. However, in patients with HF, there is an increase in oxygen consumption and 6MWD. These results indicate that ITLs in patients with HF decrease left atrial pressure, which is the key contributor to the symptoms of heart failure during physical activity.

Persistence of an iatrogenic atrial septal defect after a second-generation cryoballoon ablation of atrial fibrillation

Persistent iatrogenic atrial septal defects (iASDs) can be observed after intervention requiring a left atria (LA) access, including pulmonary vein isolation (PVI) of atrial fibrillation (AF). We investigated the incidence of iASDs post-second-generation cryoballoon ablation and the pre-procedural predictors. Eighty-three paroxysmal AF patients underwent PVI using second-generation cryoballoons. The LA was accessed with single 15-Fr steerable sheaths following a radiofrequency transseptal puncture, and the iASD was evaluated with transthoracic echocardiography (TTE), a median of 9.3 (7.1-13.3) months post-procedure. All patients underwent pre-procedural contrast-enhanced multi-detector computed tomography (CT) to evaluate the LA and PV anatomy. iASDs were detected by TTE in 7 (8.4%) patients, a median of 15.5 (6.8-17.3) months post-procedure. Patients with iASDs had significantly larger LA volumes and smaller atrial septal angles, defined as the angle between the atrial septum and sagittal line on the horizontal section at the height of the fossa ovalis, which could be the transseptal puncture site measured on CT, and more likely hypertension than those without. Multivariate analyses revealed that the atrial septal angle was the sole predictor of iASDs [odds ratio 0.764, 95% confidence interval (CI) 0.624-0.935, p = 0.009], and the optimal cut-off value was 57.5° (sensitivity 85.7%, specificity 88.2%, 95% CI 0.873-0.995, p < 0.0001). Patients with iASDs were asymptomatic and had no adverse clinical events during a 17.7 (14.4-25.8) month median follow-up. iASDs were still detectable in 8.4% of patients a median of 15.5 months after the second-generation CB ablation, and the atrial septal angle might aid in predicting persistent iASDs.

Transseptal Access to the Left Atrium: Tips and Tricks to Keep it Safe Derived from Single Operator Experience and Review of the Literature

BACKGROUND

Transseptal puncture (TSP) remains a demanding procedural step in accessing the left atrium with inherent risks and safety concerns, mostly related to cardiac tamponade.

OBJECTIVE

Based on our own experience with 249 TSP procedures and in-depth literature review, we present our results and offer several tips and tricks that may render TSP successful and safe.

METHODS

This prospective study comprised 249 consecutive patients (146 men), aged 41.6±17.4 years, undergoing TSP by a single operator for ablation of a variety of arrhythmias, mostly related to left accessory pathways (n=145) or left atrial tachycardias (n=33) and more recently, atrial fibrillation (n=70). TSP was guided by fluoroscopy alone in all patients without the use of echocardiography imaging. In addition, an extensive literature review of TSP-related topics was carried out in PubMed, Scopus and Google Scholar.

RESULTS

Among 249 patients, 33 patients were children or young adolescents (aged 7-18 years); 14 patients were undergoing a repeat procedure. Patients with a manifest accessory pathway were the youngest (mean age 33.7±15.9) and patients with atrial fibrillation the oldest (mean age 56.0±10.8 years). A successful TSP was accomplished in 247 patients (99.2%). Two (0.8%) procedures were complicated by cardiac tamponade managed successfully with pericardiocentesis or surgical drainage. Review of the literature revealed no systematic reviews and meta-analyses of TSP studies; however, several patient series have documented that fluoroscopy-guided TSP, with various modifications in the technique employed in the present series, have been effective in 95-100% of the cases with a complication rate ranging from 0.0% to 6.7%, albeit with a mortality rate of 0.018%- 0.2%. Echo imaging techniques were employed in cases with difficult TSP.

CONCLUSION

Employing a standardized protocol with use of fluoroscopy alone minimized serious complications to 0.8% (2 patients) among 249 consecutive patients undergoing TSP for ablation of a variety of cardiac arrhythmias. Based on this single-operator experience and review of the literature, a list of practical tips and tricks is provided for a successful and safe procedure, reserving the more expensive and patient inconveniencing echo-imaging techniques for difficult or failed cases.

Recognizing and reacting to complications of trans-septal puncture

INTRODUCTION

The transseptal puncture (TSP) enables access to the left heart, through the fossa ovalis (FO), both in electrophysiology and in cardiac interventional procedures. TSP is usually safe in experienced hands. Sometimes TSP can be technically demanding and carries the risk of severe complications in approximately 1%. While performing a TSP, every effort should be taken in order to avoid complications. In the event of complications, prompt recognition and reaction are essential and a combined 'heart-team' management may be the most effective approach. Areas covered: Main TSP-related complications are cardiac tamponade, aortic root puncture, embolic stroke, transient ST elevation of inferior leads and iatrogenic atrial septal defect. A challenging TSP may be expected in presence of difficult IAS-FO anatomies, previous TSP, IAS occluder device and previous IAS surgical repair. Use of echo imaging and special needles (ie., radiofrequency needle and J-shaped guidewire) may avoid TSP-related complications in difficult settings. Expert commentary: Some tools are available to help minimize the risks of TSP. However, their availability might be limited. To increase safety of TSP, an adequate training of physicians, identification of patients in whom it might be difficult and a prompt recognition of complications seem to be the most important background.

Transseptal puncture - Review of anatomy, techniques, complications and challenges

In recent years, the transseptal puncture approach has enabled passage of increasingly large and complex devices into the left atrium. Traditional tools remain effective in creating and dilating the initial puncture, with an acceptable safety profile. Even for skilled operators, the procedure is technically demanding and requires sound understanding of atrial anatomy. Intracardiac echocardiography is useful in cases of previous septal repair, poorly defined fossa ovalis anatomy or when considering patent foramen ovale portal crossing. Iatrogenic atrial septal defect (iASD) is the most commonly encountered long-term complication and there is increasing evidence that larger devices are leading to symptomatic defects. The size of the sheath crossing the septum is the strongest predictor of iASD formation but other factors such as longer procedure times, significant catheter manipulation and high pulmonary pressures also contribute. Transcatheter mitral valve repair involves the use of large 22 Fr catheters which carry alarmingly high rates of defect persistence with precipitation of symptoms and possible influence on mortality. Long-term follow up data, particularly beyond the 12-month period are lacking and resultantly, evidence to guide management is sparse. Refinements of conventional instruments, as well as innovations to puncture the septum without mechanical pressure, herald a progressively safer future for the transseptal technique.

Persistent iatrogenic atrial septal defects after pulmonary vein isolation: long-term follow-up with contrast transesophageal echocardiography

PURPOSE

Pulmonary vein isolation using cryoballoon ablation is an established approach to treating atrial fibrillation. The procedure involves insertion of a 15-Fr sheath into the left atrium across the interatrial septum. This creates an iatrogenic atrial septal defect, which may have important long-term clinical relevance, especially in younger patients. We sought to determine the long-term incidence of these defects and determine the direction of shunt using contrast transesophageal echocardiography.

METHODS

Individuals who had undergone a single pulmonary vein isolation procedure were invited to attend for transesophageal echocardiography (TOE). Patients who had undergone more than one procedure involving puncture of the interatrial septum were excluded. The interatrial septum was interrogated using two-dimensional imaging, color flow Doppler, and microbubble contrast study.

RESULTS

A total of 27 patients were recruited with a median follow-up time of 553 days from pulmonary vein isolation to TOE. Seven patients had persistent iatrogenic atrial septal defects with three demonstrating right to left shunt either at rest or with Valsalva. There were no reported adverse events during the study period.

CONCLUSIONS

Persistent iatrogenic atrial septal defects are relatively common following cryoballoon ablation procedures. Right to left shunting can be observed using microbubble contrast in a subset of patients with iatrogenic atrial septal defect (iASD). Further studies that longitudinally assess shunt fraction, pulmonary artery pressure, and the incidence of paradoxical embolism are needed to better understand the clinical impacts of such defects.

Ischemic Stroke or Systemic Embolism After Transseptal Ablation of Arrhythmias in Patients With Cardiac Implantable Electronic Devices

Background

Incidental mobile thrombi are commonly found on endovascular leads of cardiac implantable electronic devices (CIEDs). Transseptal puncture for catheter ablation of arrhythmia poses a risk for paradoxical embolism. We examined risk of ischemic stroke, transient ischemic attack (TIA), or systemic embolism after transseptal ablation in patients with and without CIEDs.

Methods and Results

Using a national administrative claims database, 31 720 patients who underwent a transseptal catheter ablation between January 2004 and September 2014 were identified. Two propensity‐matched cohorts were created by matching demographic variables, administrative variables, Charlson Comorbidity Index, CHA₂DS₂‐Vasc score, and year and indication for ablation (5533 and 11 300 patients with and without CIEDs). Incidence rates and Cox proportional hazards models were used to estimate risk of ischemic stroke, TIA, or systemic embolism for patients with and without CIEDs. Impact of oral anticoagulation (OAC) use on the endpoint was examined. Over a mean follow‐up of 2.1 years, the incidence of the combined endpoint was 1.9 per 100 person‐years in patients with CIEDs and 1.5 per 100 person‐years in patients without CIEDs (P=0.03). Among patients not on OAC, presence of a cardiac device was associated with an increased risk (hazard ratio [HR], 1.71 [1.24–2.35]; P<0.01), whereas there was no association noted among patients treated with OAC (HR, 0.98 [0.75–1.28]).

Conclusion

CIEDs are associated with an increased risk of stroke, TIA, or systemic embolism after transseptal ablation, but this risk is attenuated with postablation OAC use. Role of anticoagulation post‐transseptal ablation in patients with CIED warrants further investigation.

Outcomes Of Cryoballoon Ablation Of Atrial Fibrillation: A Comprehensive Review

Over the last decade, cryoballoon ablation has emerged as an effective alternate strategy to point-by-point radiofrequency ablation for treatment of symptomatic atrial fibrillation. There are several reasons for this. First, the acute and long-term safety and efficacy associated with cryoablation appear comparable to that of radiofrequency ablation in patients with both paroxysmal and also persistent atrial fibrillation. Second, cryoablation offers certain advantages over conventional radiofrequency ablation including a gentler learning curve, shorter ablation and procedure times as well as lack of need for costly electroanatomical mapping technologies commonly utilized with radiofrequency ablation. Lastly, with the recent advent of the second-generation cryoballoon, the effectiveness of cryoablation has further improved dramatically. This comprehensive review examines the gradual evolution of the cryoablation tools as well as the rationale and data in support of the currently-available cryoballoon technologies for catheter ablation of atrial fibrillation.