Meta-Analysis Comparing Cryoballoon Versus Radiofrequency as First Ablation Procedure for Atrial Fibrillation

Pulmonary vein isolation is the cornerstone of atrial fibrillation (AF) ablation. Radiofrequency (RF) represents a standard of care for pulmonary vein isolation, whereas cryoballoon (CB) ablation has emerged as a valid alternative. The aim of our meta-analysis was to explore the efficacy and safety of CB compared with RF as first ablation procedure for AF. We searched the literature for studies that investigated this issue. The primary efficacy outcome was AF recurrence. The safety outcomes were: pericardial effusion, cardiac tamponade, phrenic nerve palsy, vascular complications, and major bleedings. Fourteen randomized controlled studies and 34 observational studies were included in the analysis. A total of 7,951 patients underwent CB ablation, whereas 9,641 received RF ablation. Mean follow-up was 14 ± 7 months. Overall, CB reduced the incidence of AF recurrence compared with RF ablation (relative risk [RR] 0.86; 95% confidence interval [CI] 0.78 to 0.94; p = 0.001), and this result was consistent across different study design and AF type. CB had a significantly higher rate of phrenic nerve palsy, whereas it was related to a lower incidence of pericardial effusion, cardiac tamponade (RR 0.58; 95% CI 0.38 to 0.88; p = 0.011) and vascular complications (RR 0.61; 95% CI 0.48 to 0.77; p <0.001) compared with RF. There was no significant difference in major bleedings between the 2 strategies. CB ablation had a shorter procedural time compared with RF (mean difference -20.76 minutes; p <0.001). In conclusion, considered its efficacy/safety profile and short procedural time, CB ablation represents the preferable option for first AF ablation procedure.

Incidence of early pulmonary vein reconnections using different energy sources for pulmonary vein isolation: Multielectrode phased radiofrequency vs second-generation cryoballoon

OBJECTIVE

To determine and compare the incidence of early recurrence of conduction after pulmonary vein isolation (PVI) using two different ablation technologies: phased radiofrequency by a multipolar ablation catheter (PVAC) and cryo-ablation by a second-generation cryoballoon (CB).

METHODS AND RESULTS

Two hundred patients (pts) with atrial fibrillation underwent PVI with PVAC (Group 1) or CB (Group 2), with 100 pts in each group. The incidence of PV reconnection (PVR) for each vein was examined in both groups at least 30 minutes after successful PVI. There were no significant clinical differences between both groups. Total procedure-, fluoroscopy-, and left atrial (LA) dwell time were significantly shorter in Group 2 pts (P < .0001). Early PVR was recorded in 69/388 (18%) isolated PVs or left common trunks (CTs) in Group 1 compared with 25/386 (7%) in Group 2 (P < .0001). Forty-three pts in Group1 were found to have PVR compared with 22 pts in Group 2 (P = .0015). Group 1 pts with CTs showed significantly more PVR than pts of Group 2 (P = .047). In both groups, CTs and CT branches were found to reconnect significantly more frequent compared with all other veins.

CONCLUSION

Both PVAC and CB are effective to achieve PVI. Early PVR is observed with the significantly lower frequency with second-generation CB compared with PVAC, contributing to shorter procedure-, fluoroscopy, and LA dwell times. CTs and CT branches exhibit the highest incidence of PVR for both devices.

Real-Time Recordings in Cryoballoon Pulmonary Veins Isolation: Comparison Between the 25mm and the 20mm Achieve Catheters

AIMS

Real Time Recordings (RTR) of pulmonary vein (PV) activity provide important information in the setting of the 2nd generation Cryoballoon (CB-A), as a funcion of time to isolation. Visualization of RTR with the standard inner lumen mapping catheter (ILMC) 20mm Achieve (AC) is possible in roughly 50% of PVs. A novel 25mm-Achieve Advance (AC-A) has been developed with the aim of increasing the detection of RTR. The purpose of this study is to compare the AC-A with the AC, to feasibility and improvement of RTR.

METHODS

We assigned 50 patients with paroxysmal or persistent atrial fibrillation to CB-A PVI, using the AC-A as ILMC. We compared this group with 50 patients, matched for age and left atrial volume, who previously underwent the CB-A PVI using the AC.

RESULTS

RTR were more frequently observed with the AC-A than with the AC (74% vs 49%; p= 0.02). RTR in the left superior PVs was similar in both groups (74% vs 72%, p= 0.8). RTR with the AC-A were equally appreciated in left or right sided, superior or inferior PVs. No significant differences were found in terms of feasibility, procedure fluoroscopy and freezing times, nadir temperatures, and acute PVI.

CONCLUSIONS

CB-A PVI with the AC-A is feasible and safe in all PVs. The AC-A has proven significantly superior in visualising RTR if compared to the AC, affording RTR in 74% of PVs.

Characteristics of dormant pulmonary vein conduction induced by adenosine triphosphate in patients with atrial fibrillation undergoing cryoballoon ablation

BACKGROUND

Adenosine triphosphate (ATP) can provoke acute reconnections after pulmonary vein isolation (PVI). This study aimed to investigate dormant conduction (DC) after ablation with second-generation cryoballoon (CB).

METHODS

Two hundred sixteen patients (148 male; age 64±9 years) with atrial fibrillation (AF) were included. After a successful PVI with the CB, 20mg of ATP was administered. All patients were followed up for 425±56 days.

RESULTS

Seven hundred ninety-five out of 864 (92%) PVs were successfully isolated solely by the CB. DCs were revealed in 8 (3.7%) after ATP injections. AF recurrences occurred in 2 out of 8 patients, while no AF recurrences could be documented in 6 out of 8 patients with DCs after a blanking period of 3 months (25% vs. 75%). In contrast, 29 (13.9%) patients without DCs had AF recurrences, and there was no significant difference between those with and without DCs regarding the recurrence rate of AF (p=0.38). There were no reliable predictors of DCs after the PVI with the CB.

CONCLUSION

The present study demonstrated a low rate of transient PV reconnection after adenosine infusion following successful PVI with the CB. There was no reliable predictor of DCs. Further studies will be needed in order to appreciate the prognostic value of adenosine testing after successful PVI with the CB.

Combined Cryoballoon and Radiofrequency Ablation Versus Radiofrequency Ablation Alone for Long-Standing Persistent Atrial Fibrillation

BACKGROUND

To achieve sinus rhythm, ablation of long-standing persistent atrial fibrillation (LSPAF) usually requires substrate modification in addition to pulmonary vein isolation (PVI). In the present article, we aimed to compare clinical and substrate modification effects of 2 distinct PVI strategies during stepwise ablation in patients with LSPAF: (1) Combined approach: cryoballoon (CB) for PVI and radiofrequency (RF) ablation for substrate modification and (2) RF-only approach: RF ablation for both PVI and substrate modification.

MATERIALS AND METHODS

A total of 34 patients were divided into 2 groups: 19 in the combined group and 15 in the RF group. Left atrial (LA) complex fractionated atrial electrogram (CFAE) maps were acquired before and after PVI and compared between groups. The groups were compared for acute atrial fibrillation termination (AFT) rates and long-term arrhythmia-free survival.

RESULTS

A significant reduction on total LA CFAE area was observed with PVI in both groups. In the CB group, when pulmonary veins were excluded, the reduction of LA CFAE area was the most significant on the posterior wall of left atrium and which was greater than in the RF group. Although the ratio of AFT was higher in the CB group (44% versus 33%, respectively), single-procedure arrhythmia-free survival at 1 year was comparable between groups (68% in the CB group versus 66% in the RF group). Times of total procedure, fluoroscopy and post-PVI RF were all shorter in the CB group.

CONCLUSIONS

CB may cause greater substrate modification on the posterior wall and increase AFT rate during LSPAF ablation.

Repeat procedures using the second-generation cryoballoon for recurrence of atrial fibrillation after initial ablation with conventional radiofrequency

PURPOSE

Pulmonary vein isolation is now widely accepted for the treatment of symptomatic atrial fibrillation refractory to antiarrhythmic drugs. However, multiple procedures are often required to significantly reduce atrial fibrillation (AF) recurrence. In the present study, we analyzed the acute results and the midterm clinical outcome of a second-generation cryoballoon ablation (CB-A) performed during repeat procedures for recurrence of AF after an initial procedure performed with conventional radiofrequency (RF).

METHODS

Consecutive patients with paroxysmal and persistent AF who underwent pulmonary vein isolation by CB-A from June 2012 in our hospital as a redo procedure after a previous pulmonary vein isolation with RF were retrospectively included in this analysis.

RESULTS

Forty-seven patients having undergone CB-A as a redo procedure were considered for our analysis. Pulmonary vein potentials were documented in 83 pulmonary veins (PV) that were all successfully re-isolated using the CB-A. Transient phrenic nerve palsy was the only complication occurring in our study cohort. After a mean follow-up of 15 ± 8 months, 76.6% of patients were free from recurrence of atrial fibrillation. If taking into consideration a 3-month blanking period, 83% of patients were free from recurrence. The success rate in patients affected by paroxysmal AF was 87% at final follow-up following the blanking period.

CONCLUSIONS

The second-generation CB is effective in treating recurrence of AF after a previous ablation performed with conventional RF. Considering a 3-month blanking period, 83% of the patients were free from any atrial tachycardia recurrence during a 15-month follow-up. This approach proved particularly successful in patients affected by paroxysmal AF.

Long-Term Evolution of Patients Treated for Paroxysmal Atrial Fibrillation with First and Second Generation Cryoballoon Catheter Ablation with a Prospective Protocol Guided by Complete Bidirectional Left Atrium-Pulmonary Veins Disconnection after Adenosine as Main Target end Point to achieved. Seven Years Follow-up of Patients with a rough estimation profile of Low ALARMEc Score. A Single Center Report

INTRODUCTION

Cryoballoon ablation (CB) has proven effective for treating patients with paroxysmal atrial fibrillation (PAF). We analyzed our seven year follow-up of patients, treated for PAF with first (CB1) and second generation (CB2), with demonstration of LA-PV disconnection with bidirectional block (BB) after adenosine (AD).

METHODS

Since November 2008 to May 2015, 128 patients, 97 male (58±7 years), without heart disease, highly symptomatic, refractory to antiarrhythmic drugs (AAD) were treated, and follow-up (1411 ±727 days). Left atrial size: 37±6 mm.

RESULTS

A total of 439 PV were successfully isolated (91.9%). Acute reconduction: 44 PV (9%): 16 after CB; 16 unmasked by AD; 12 extrapulmonary muscular connections (EMC). Main complication was phrenic nerve palsy (PNP): 9 (7 %). On follow-up, 114 patients (89%) remain asymptomatic in sinus rhythm (SR), free of medication. Fourteen patients (11%) had arrhythmia recurrence: 12 male (52±8 years). Early recurrences occurred in 9 male. Late recurrences presented 3 male at 24, 27 and 60 months, and 2 female at 7 and 40 months respectively. All recurrence patients were Redo, and remain in SR without medication during follow-up.

CONCLUSIONS

CB alone is very effective and safe for the definitive treatment of patients suffering PAF with 72.6% success rate, increasing up to 89.1% when this protocol is applied in a single procedure. After Redo, all population group (100%), remain in sinus rhythm, freedom of arrhythmia, without AAD, in this very long term follow-up. Checking for BB, AD protocol, and ruling out EMC allowed-us to identified 14.8% of patients with underlying substrate for potential arrhythmia recurrence. CB2 applications entail a highest risk of PNP. Patients with a rough estimated profile of low ALARMEc score (≤ 1) have an excellent long term outcome, being this series the largest follow-up described so far, for patients treated for PAF with CB.

[Interventional treatment for paroxysmal atrial fibrillation : which is the optimal ablation approach?]

Atrial fibrillation is one of the most common arrhythmias and effects probably more than 35 million people worldwide. The incidence in patients older than 70 years of age is as high as 10%. One can expect that according to our demographic development this entity will be increasingly important within the next years and decades. Along with the well know and established but at the same time limited opportunities of pharmacological treatment option of this arrhythmia, catheter ablation has evolved as a safe and effective treatment option. Electrical isolation of the pulmonary vein remains the standard of care and results in success rates as high as 80% using modern ablation strategies. Optimization of procedural and ablation techniques has lead to this high success rates. Different energy sources are available, such as radiofrequency, cryoenergy and laser are widely used today to treat patients with symptomatic atrial fibrillation. PV isolation using a so called "single-shot" ablation approach has shown to be effective with a reduced requirement of periprocedural resources and therefore resulting in wider application of this treatment not only in specialized electrophysiological centers. The rapid development in this field leads to the question which approach can be used as the most likely to result in the highest success and least complication rates. This question will be addressed in the following manuscript.

Comparison of pulmonary vein isolation using cryoballoon versus conventional radiofrequency for paroxysmal atrial fibrillation

The aim of this study was to compare the results of pulmonary vein isolation using conventional irrigated radiofrequency (RF) approach versus the cryoballoon (CB) ablation. From January 2008 to December 2011, a total of 426 patients with drug-resistant symptomatic paroxysmal atrial fibrillation underwent pulmonary vein isolation as the index procedure by conventional manual RF or CB ablation at our center. A final population of 396 patients was considered for analysis and divided into 2 groups: conventional RF ablation (n = 260) and CB ablation (n = 136). At a mean follow-up of 23 ± 13 months (median 27, range 4 to 68), the success rate for RF ablation group was 57.3% (149 patients) and was 63.2% (86 patients) for cryoablation group (p = 0.25). Procedural times were significantly shorter in the cryoablation group (192 ± 49 vs 112 ± 58 minutes, p <0.000001) but not fluoroscopy times (36 ± 14 vs 31 ± 17 minutes, p = 0.45). No clinical predictors were found to predict atrial fibrillation recurrences. Complication rates were similar in both groups except for phrenic nerve palsy that was uniquely observed in the CB group (8.1%, p <0.00001). All phrenic nerve palsies resolved during follow-up. In conclusion, on a medium-term follow-up, conventional point-by-point RF ablation and CB ablation showed similar success rates. Procedural times were significantly shorter in the CB approach. The most frequent complication during CB procedures was phrenic nerve palsy, which occurred in 8.1% of patients and resolved in all during the follow-up period.

Pulmonary vein isolation in patients with Brugada syndrome and atrial fibrillation: a 2-year follow-up

AIMS

Pharmacological treatment of atrial fibrillation (AF) in the setting of Brugada syndrome (BS) might be challenging as many antiarrhythmic drugs (AADs) with sodium channel blocking properties might expose the patients to the development of ventricular arrhythmias. Moreover, patients with BS and implantable cardioverter-defibrillator (ICD) might experience inappropriate shocks because of AF with rapid ventricular response. The role of pulmonary vein isolation (PVI) in patients with BS and recurrent episodes of AF has not been established yet. In this study, we analysed the outcome of PVI using radiofrequency energy or cryoballoon (CB) ablation at 2 years follow-up.

METHODS AND RESULTS

Consecutive patients with BS having undergone PVI for drug-resistant paroxysmal AF were eligible for this study. Nine patients (three males; mean age: 52 ± 26 years) were included. Six patients (67%) had an ICD implanted of whom three had inappropriate shocks because of rapid AF. At a mean 22.1 ± 6.4 months follow-up, six patients (67%) were free of AF without AADs. None of the three patients who had experienced inappropriate ICD interventions for AF had further ICD shocks after ablation.

CONCLUSION

In our study PVI can be an effective and safe procedure to treat patients with BS and recurrent episodes of paroxysmal AF.

Ablation of atrial fibrillation with cryoballoon or duty-cycled radiofrequency pulmonary vein ablation catheter: a randomized controlled study comparing the clinical outcome and safety; the AF-COR study

AIMS

The urge to facilitate the atrial fibrillation (AF) ablation procedure has led to the development of new ablation catheters specifically designed as 'one-shot tools' for pulmonary vein isolation (PVI). The purpose of this study was to compare the efficacy, safety, and procedure times for two such catheters using different energy sources.

METHODS AND RESULTS

One hundred and ten patients, referred for ablation of paroxysmal or persistent AF, were randomized to treatment with either the cryoballoon or the circular multipolar duty-cycled radiofrequency-based pulmonary vein ablation catheter (PVAC). Complete PVI was achieved in 98 vs. 93% patients in the cryoballoon and PVAC group, respectively, with complication rates of 8 vs. 2% (P = 0.2). Complete freedom from AF, without antiarrhythmic drugs, after one single ablation procedure was seen in 46% in the cryoballoon vs. 34% after 12 months (P = 0.2). Procedure times were comparable, but fluoroscopy time was shorter for the cryoballoon (32 ± 16 min) than for the PVAC procedures (47 ± 17 min) (P < 0.001). A significant improvement of quality of life (QoL) and arrhythmia-related symptoms was seen in both groups after ablation.

CONCLUSION

Both catheters proved comparably effective and safe in achieving acute PVI, apart from the shorter fluoroscopy times achieved with the cryoballoon. At follow-up, there was no statistically significant difference between the groups regarding freedom from AF and clinical success. The QoL increased to the same levels as for the general Swedish population in both groups.

The Future of Pulmonary Vein Isolation - Single-shot Devices, Remote Navigation or Improving Conventional Radiofrequency Delivery by Contact Monitoring and Lesion Characterisation?

Pulmonary vein isolation is the main goal of atrial fibrillation (AF) ablation to date. Lack of isolation is associated with an increased risk of AF recurrences. Precise navigation to specific target sites, catheter stability and appropriate contact force are requisites for effective radiofrequency applications. Conventional manual-guided point-by-point radiofrequency energy delivery shows limitations to reach them, especially when performed by non-experienced electrophysiologists. New technological alternatives are rapidly arising and becoming clinically available to overcome some of the manual-guided radiofrequency delivery shortcomings. Here, we review the most recent clinical data, potential advantages, shortcomings and future directions of the new ablation strategies for pulmonary vein isolation.

Usefulness of Contrast Intracardiac Echocardiography in Performing Pulmonary Vein Balloon Occlusion during Cryo-ablation for Atrial Fibrillation

BACKGROUND

Cryoballoon ablation (CBA) has been proven to be very effective for pulmonary vein (PV) isolation (PVI) if complete occlusion is achieved and conventionally assessed by angiographic injection of contrast within PV lumen. The aim of our study was to assess the usefulness of saline contrast intracardiac echocardiography in guiding CBA with respect to PV angiography.

METHODS

Thirty consecutive patients with paroxysmal atrial fibrillation were randomly assigned fluoroscopy plus color-flow Doppler (n = 15; group 1: an iodinated medium as both angiographic and echographic contrast) or contrast intracardiac echocardiography plus color-flow Doppler (n = 15; group 2: saline contrast) for guidance of CBA.

RESULTS

We evaluated 338 occlusions of 107 PVs. The intracardiac echocontrastography-guided assessment of occlusion, defined as loss of echocontrastographic back-flow to the left atrium after saline injection regardless of the visualization of PV antrum, showed a high level of agreement with the angiographic diagnosis of occlusion. PVI rate was similar in both groups and effectively guided by intracardiac echocontrastography (PVI using ≤ 2 double cryofreezes: 89% of PVs in group 1 vs. 91% in group 2; p=n.s.). Group 2 patients had significantly shorter procedure (127 ± 16 vs. 152 ± 19 minutes; p<0.05) and fluoroscopy times (30 ± 12 vs. 43 ± 9 minutes, p<0.05) and used a lower iodinated contrast (88 ± 26 vs. 190 ± 47 mL, p<0.05).

CONCLUSIONS

PV occlusion and PVI during cryoablation can be effectively predicted by intracardiac saline echocontrastography. This technique reduces procedural time, radiological exposure and iodinated contrast use.

Verification of pulmonary vein isolation during single transseptal cryoballoon ablation: a comparison between the classical circular mapping catheter and the inner lumen mapping catheter

AIMS

Cryoballoon ablation has proven very effective in achieving pulmonary vein isolation (PVI). The novel Achieve inner lumen mapping catheter designed to be used in conjunction with the cryoballoon, serves as both a guidewire and a mapping catheter. To our knowledge, this is the first study comparing the latter to verification of electrical isolation with the 'traditional' circular mapping catheter.

METHODS AND RESULTS

We assigned 40 consecutive patients matched for age and left atrial diameter suffering of paroxysmal atrial fibrillation to cryoballoon PVI using either the circular mapping catheter or the Achieve as a mapping catheter. Duration of procedure as well as fluoroscopy times were significantly lower in the Achieve group than in the circular mapping catheter group (111 ± 14 min vs. 126 ± 13 min, P < 0.005 and 22 ± 5 min vs. 29 ± 4 min, P < 0.0001, respectively). There were no significant differences between both groups in terms of mean degree of occlusion, mean minimal temperatures, and PVI. Pulmonary vein isolation could be documented by real-time recordings in 55% of veins in the Achieve group with mean time to isolation of 65 ± 23 s.

CONCLUSION

Cryoballoon ablation in conjunction with the novel Achieve is feasible, safe, and affords PVI in nearly all veins in similar proportions to the approach with the traditional guidewire. Furthermore, if compared to the procedure with the circular mapping catheter, cryoballoon ablation with the Achieve is significantly faster and associated to shorter fluoroscopy times.

Achieving elongated lesions employing cardiac cryoablation: a preclinical evaluation study

Cardiac cryoablation applied for treating cardiac arrhythmias has shown promising results after intervention, particularly for the creation of elongated lesions. A model for simulating and assessing cryoablation interventions was developed, evaluated and validated with animal experiments. We employed two simulations of different freezing outlet settings for a loop shaped cryocatheter, applying Pennes heat equation for cardiac tissue. Our experiments demonstrated that an equidistantly spaced freezing outlet distribution of 5mm led to an improved formation of lesions, i.e., elongated lesions were observed throughout the transmural cardiac volume and on the epicardial structure. A complete transmural frozen lesion was not achieved with a freezing outlet distance of 10mm. These simulation results could be experimentally verified by morphological and histological examinations. Using our simulation model we were able to optimize the intervention procedure by predicting and assessing the freezing process. This should further increase the success rate of cardiac cryoablation in clinical interventions.

Cryoballoon ablation for atrial fibrillation

Focal point-by-point radiofrequency catheter ablation has shown considerable success in the treatment of paroxysmal atrial fibrillation. However, it is not without limitations. Recent clinical and preclinical studies have demonstrated that cryothermal ablation using a balloon catheter (Artic Front©, Medtronic CryoCath LP) provides an effective alternative strategy to treating atrial fibrillation. The objective of this article is to review efficacy and safety data surrounding cryoballoon ablation for paroxysmal and persistent atrial fibrillation. In addition, a practical step-by-step approach to cryoballoon ablation is presented, while highlighting relevant literature regarding: 1) the rationale for adjunctive imaging, 2) selection of an appropriate cryoballoon size, 3) predictors of efficacy, 4) advanced trouble-shooting techniques, and 5) strategies to reduce procedural complications, such as phrenic nerve palsy.

Cryoballoon catheter ablation in atrial fibrillation

Pulmonary vein isolation with catheter ablation is an effective treatment in patients with symptomatic atrial fibrillation refractory or intolerant to antiarrhythmic medications. The cryoballoon catheter was recently approved for this procedure. In this paper, the basics of cryothermal energy ablation are reviewed including its ability of creating homogenous lesion formation, minimal destruction to surrounding vasculature, preserved tissue integrity, and lower risk of thrombus formation. Also summarized here are the publications describing the clinical experience with the cryoballoon catheter ablation in both paroxysmal and persistent atrial fibrillation, its safety and efficacy, and discussions on the technical aspect of the cryoballoon ablation procedure.

Cryoballoon temperature predicts acute pulmonary vein isolation

BACKGROUND

Cryoballoon pulmonary vein isolation (PVI) currently requires a long cryoballoon application (CBA) time of 240 to 300 seconds, thus repeated ineffective CBA prolongs procedure duration. We hypothesized that cryoballoon temperature (CBT) may be used to discriminate between effective and ineffective CBA during freezing.

OBJECTIVE

This study sought to evaluate CBT as a predictor of CBA efficiency.

METHODS

Sixty-six patients with atrial fibrillation underwent PVI using the single big (28 mm) cryoballoon technique. CBT was continuously recorded. After each CBA (300 seconds), a Lasso catheter (Biosense Webster, Inc., Diamond Bar, California) was placed into the target pulmonary vein (PV) to determine whether electrical PV disconnection was present. Only the first CBA at each PV was analyzed to avoid cumulative effects.

RESULTS

The CBT was lower during CBA at superior compared with inferior PVs. When individual CBAs were grouped according to successful/failed PVI, CBT was lower for those CBAs that resulted in successful PVI at all time points analyzed. To test the performance of CBT to predict failed CBA, receiver-operator curves were constructed. A minimal CBT of ≥ -42°C/ -39°C (superior/inferior PVs) predicted failed PVI with 73%/92% specificity (area under the curve 0.82/0.81); positive predictive value (PPV) 74%/74%. A minimal CBT of < -51°C was invariably associated with PVI. After 120 seconds of freezing, a CBT of ≥ -36°C/ -33°C (superior/inferior PVs) predicted failed PVI with 97%/95% specificity (area under the curve 0.82/0.76); PPV 82%/80%.

CONCLUSION

Balloon temperature predicts successful target PVI during cryoablation and may serve in the early identification of noneffective balloon applications.

The incidence and long-term clinical outcome of iatrogenic atrial septal defects secondary to transseptal catheterization with a 12F transseptal sheath

BACKGROUND

Studies assessing the presence of a residual iatrogenic atrial septal defect (iASD) after transseptal catheterization with 8F transseptal sheaths have suggested that the majority of these iASDs close within 6 months. However, these studies have been limited by small patient numbers and short follow-up. Additionally, there are a number of novel catheter procedures in interventional cardiology and electrophysiology that use larger transseptal sheaths. The objective of this study was to assess the incidence of and complications associated with iASDs in a large cohort of patients undergoing transseptal catheterization with a 12F transseptal sheath.

METHODS AND RESULTS

Patients (n=253) without a preexisting interatrial shunt undergoing WATCHMAN implantation as part of the PROTECT AF study were included in this current study. Patients underwent transesophageal echocardiography with echo-contrast immediately after the procedure and at 45 days and 6 months and 12 months. Eighty-seven percent of patients had an iASD immediately after the procedure, the majority of which sealed by 6 months (incidence of iASD, 34% at 45 days, 11% at 6 months, 7% at 12 months). Whereas the majority of iASDs were >3 mm in diameter immediately after the procedure, the minority of iASD were >3 mm during the follow-up period. Additionally, interatrial shunting was predominantly left-to-right when an iASD was present. There was no significant difference in the rate of stroke and/or systemic embolism during the follow-up period in patients with or without iASD.

CONCLUSIONS

Transseptal catheterization procedures with a large-diameter transseptal sheath have a high spontaneous closure rate of iASDs that is not associated with an increased rate of stroke/systemic embolization during long-term follow-up.