Left Ablation Research Articles

Applications of multimodality imaging for left atrial catheter ablation.

Atrial arrhythmias, including atrial fibrillation and atrial flutter, may be treated through catheter ablation. The process of atrial arrhythmia catheter ablation, which includes patient selection, pre-procedural planning, intra-procedural guidance, and post-procedural assessment, is typically characterized by the use of several imaging modalities to sequentially inform key clinical decisions. Increasingly, advanced imaging modalities are processed via specialized image analysis techniques and combined with intra-procedural electrical measurements to inform treatment approaches. Here, we review the use of multimodality imaging for left atrial ablation procedures. The article first outlines how imaging modalities are routinely used in the peri-ablation period. We then describe how advanced imaging techniques may inform patient selection for ablation and ablation targets themselves. Ongoing research directions for improving catheter ablation outcomes by using imaging combined with advanced analyses for personalization of ablation targets are discussed, together with approaches for their integration in the standard clinical environment. Finally, we describe future research areas with the potential to improve catheter ablation outcomes.

Safety and Medium- and Long-Term Efficacy of Treating Atrial Fibrillation with Surgical Radiofrequency Ablation during Concomitant Mitral Valve Surgery

To investigate the safety and medium- and long-term efficacy of surgical radiofrequency ablation to treat atrial fibrillation during concomitant mitral valve surgery. From January 2014 to December 2018, 280 patients with mitral valve disease and the comorbidity of preoperative atrial fibrillation were recruited for the study. Among them, 130 patients received only mitral valve surgery (non-ablation group), and 150 patients were underwent surgical radiofrequency ablation for the atrial fibrillation during concomitant mitral valve surgery (ablation group). Among the 150 patients of the ablation group, 80 had biatrial ablation, and 70 had left atrial ablation. Under general anesthesia, median sternotomy was done on all patients and cardiopulmonary bypass was established through the ascending aorta and superior and inferior venae cavae. After aortic occlusion, patients in the ablation group underwent the ablation procedure with the Atricure® bipolar ablation device, using the Cox Maze Ⅲ procedure as a reference. In addition, the left atrial appendage was removed and electrocautery of the ligament of Marshall and Waterston's groove were performed in all Cox Maze cases. Following ablation, mitral valve replacement or repair was performed. All patients were given 200 mg oral amiodarone on the first day after surgery, for three times/d×7 d, which was followed by twice/d×7 d, and then oral amiodarone 200 mg/d was maintained till the end of 3 months after surgery (ablation group) or 12 months after surgery (non-ablation group). Patients were followed up at the intervals of 3 months, 6 months, 12 months, 2 years, 3 years, and 5 years after discharge. The follow-up service included standard 12-lead chest electrocardiogram (ECG) and 24-h dynamic ECG. The primary end point of the study was the time point of postoperative atrial fibrillation and the secondary endpoints were major cardiovascular events, death, and readmission due to heart failure. The surgeries were successfully performed in all subjects of the study. A total of 30 patients were lost to follow-up within 5 years after operation (10.7% losses to follow-up), including 11 patients in the ablation group and 19 patients in the non-ablation group. The proportion of patients who did not have atrial fibrillation in the ablation group and the non-ablation group at 6 months, 12 months, 2 years, 3 years and 5 years after surgery was 83.3% and 27.7%, 72.7% and 20.8%, 66.0% and 15.4% 61.3% and 13.1%, and 43.3% and 10.8%, respectively, with the data from the two groups showing statistically significant difference ( P<0.001). The proportion of patients who did not have atrial fibrillation in the biatrial ablation and the left atrial ablation group at 6 months, 12 months, 2 years, 3 years and 5 years after surgery was 87.3% and 87.5%, 92.4% and 82.8%, 90.5% and 85.7%, 94.8% and 88.1%, and 75.5% and 69.4%%, respectively, with the data from the two groups showing no statistically significant difference ( P>0.05). However, the cumulative incidence of atrial fibrillation in the two groups showed statistically significant difference ( P<0.001). There were no deaths within 30 days after operation in either group. There was no significant difference in cerebrovascular accident, readmission for heart failure, pulmonary infection and mediastinal infection between the two groups within one year after operation ( P>0.05). However, the proportion of patients who had permanent pacemaker installed due to Ⅲ-degree atrioventricular block in the ablation group was higher than that in the non-ablation group ( P<0.05). The proportion of patients who required re-drainage due to delayed pericardial effusion in the ablation group was higher than that in the non-ablation group ( P<0.05). In the group of patients who had modified Cox Maze procedure with bipolar ablation device to treat atrial fibrillation during concomitant mitral valve surgery, the maintenance rate of sinus rhythm after cardioversion was significantly higher than that in the non-ablation group. The surgery showed better safety and significantly better medium- and long-term outcomes. Left atrial ablation and biatrial ablation were both considered safe and effective surgical treatment for atrial fibrillation. Compared with the left atrial ablation group, the biatrial ablation group achieved better effects in restoring and maintaining sinus rhythm without an increase the incidence of perioperative complications.

Impact of Active Esophageal Cooling on Fluoroscopy Usage During Left Atrial Ablation.

Risks to collateral structures exist with radiofrequency (RF) ablation of the left atrium to obtain pulmonary vein isolation (PVI) for the treatment of atrial fibrillation. Passive luminal esophageal temperature (LET) monitoring is commonly utilized, but increasing data suggest limited benefits with LET monitoring. In contrast, active cooling of the esophagus has been shown to significantly reduce esophageal injury. Active cooling of the esophagus also avoids the need for stopping and repositioning an LET probe during use, which may reduce the need for fluoroscopy use. This study aimed to measure the impact on fluoroscopy use during RF ablation with esophageal cooling using a dedicated cooling device in a low-fluoroscopy practice. All patients who underwent PVI over a one-year timeframe by a single provider were analyzed. Patients undergoing PVI prior to the incorporation of an esophageal cooling protocol into standard ablation practice were treated with traditional LET monitoring. Patients treated after this point received active esophageal cooling, in which no LET monitoring is utilized. A total of 280 patients were treated; 91 patients were treated using LET monitoring, and 189 patients were treated with esophageal cooling. The mean total fluoroscopy time before the implementation of the esophageal cooling protocol in 91 patients was 194 seconds [standard deviation (SD): 182 seconds] per case, with a median of 144 seconds. The mean total fluoroscopy time after implementation in 189 patients was 126 seconds (SD: 120 seconds) per case with a median of 96 seconds, representing a reduction of 35% per case (p < 0.0001, Mann–Whitney U test). In this largest study to date of active esophageal cooling during PVI, a 35% reduction in fluoroscopy time compared with patients who received LET monitoring was found. This reduction was seen despite an already low fluoroscopy usage rate in place.

Sex Differences in Ablation Strategy, Lesion Sets, and Complications of Catheter Ablation for Atrial Fibrillation: An Analysis From the GWTG-AFIB Registry

When presenting for atrial fibrillation (AF) ablation, women, compared with men, tend to have more nonpulmonary vein triggers and advanced atrial disease. Whether this informs differences in AF ablation strategy is not well described. We aimed to characterize ablation strategy and complications by sex, using the Get With The Guidelines-AF registry. From the Get With The Guidelines-AF registry ablation feature, we included patients who underwent initial AF ablation procedure between January 7, 2016, and December 27, 2019. Patients were stratified based on AF type (paroxysmal versus nonparoxysmal) and sex. We compared patient demographics, ablation strategy, and complications by sex. Among 5356 patients from 31 sites who underwent AF ablation, 1969 were women (36.8%). Women, compared with men, were older (66.8±9.6 versus 63.4±10.6, P<0.0001) and were more likely to have paroxysmal AF (59.4% versus 49.5%, P<0.0001). In women with nonparoxysmal AF, left atrial linear ablation was more frequent (roof line: 53.9% versus 45.3%, P=0.0002; inferior mitral isthmus line: 10.2% versus 7.0%, P=0.01; floor line: 46.1% versus 40.6%, P=0.02) than in men. In multivariable analysis, the association between patient sex and complications from ablation was not statistically significant. In this US wide AF ablation quality improvement registry, women with nonparoxysmal AF were more likely to receive adjunctive lesion sets compared with men. These findings suggest that patient sex may inform ablation strategy in ways that may not be strongly supported by evidence and emphasize the need to clarify optimal ablation strategies by sex.

Comparative characteristics of a pacemaker implantation after biatrial or left atrial ablation of atrial fibrillation in combination with coronary artery bypass grafting in patients with ischemic heart disease and long-standing persistent atrial fibrillation.

Aim To compare the incidence of a permanent pacemaker (PP) implantation based on the chosen treatment technology (biatrial ablation, BA, or left atrial ablation (LAA) for long-standing persistent atrial fibrillation (AF) with simultaneous coronary bypass (CB).Material and methods The study included 116 patients with long-standing persistent AF and indications for CB. Patients were randomized to two equal groups (58 patients in each). Group 1 underwent BA in combination with CB; group 2 patients underwent isolated LAA with simultaneous CB under the conditions of artificial circulation. Incidence of PP implantation was assessed during the early (to 30 days) and late (to 60 months) postoperative periods.Results For the observation period, a total of 9 PPs was implanted in both groups, 6 in the BA group and 3 in the LAA group (odds ratio, OR, 0.5; 95 % confidence interval, CI, 0.1-2.4; р=0.490). During the early postoperative period, 5 patients in the BA group and 2 patients in the LAA group were implanted with PP (OR, 0.4; 95 % CI. 0-2.5; р=0.438). During the late postoperative period, one (2%) patient of the BA group was implanted with a permanent PP at 30 months of follow-up due to the development of sick sinus syndrome (SSS); also, one (2%) patient of the LAA group required PP implantation at 54 months of follow-up due to the development of SSS. The causes for PP implantation in the BA group included the development of complete atrioventricular (AV) block in 9 % of cases (95 % CI, 4-19 %); sinus node dysfunction and junctional rhythm in 2 % of cases (95 % CI, 0-9 %). Compared to this group, the LAA group showed a statistically significant difference in the incidence of AV block (0 cases, р=0.047). The major cause for PP implantation in the LAA group was the development of sinus node dysfunction in 3 (5 %) patients (95 % CI, 2-14 %).Conclusion The use of BA in surgical treatment of long-standing persistent AF with simultaneous myocardial revascularization is associated with a high risk of AV block, which requires permanent PP implantation in the postoperative period. Total incidence of permanent PP implantation for dysfunction of the cardiac conduction system following the combination surgical treatment of long-standing persistent AF and IHD, either CB and LAA or BA, did not differ between the treatment groups both in early and late postoperative periods.

Quality of life in patients with long-standing persistent atrial fibrillation after surgical ablation and simultaneous coronary artery bypass grafting

Aim. To analyze quality of life (QOL) of patients with coronary artery disease (CAD) in combination with long-standing persistent atrial fibrillation (AF) in the long-term postoperative period, depending on chosen surgical strategy for concomitant pathology.Material and methods. The analysis of QOL changes in the long-term postoperative period (12 and 24 months) in 116 patients with CAD and concomitant long-term persistent AF who selectively underwent biatrial (BA) or isolated left atrial (LA) ablation with simultaneous on-pump coronary artery bypass grafting. To assess QOL, a non-specific Medical Outcomes Study 36-Item Form Health Status Survey (SF-36) questionnaire was used. Patients were questioned in preoperative and long-term postoperative periods (12 and 24 months).Results. All SF-36 parameters significantly improve after open surgical treatment in the long-term postoperative period (24 months) with both treatment strategies (BA and LA ablation) for AF. In the BA ablation group, 74% of patients did not have arrhythmia after 12 months, and only 38,5% of patients in the LA ablation group belonged to European Heart Rhythm Association (EHRA) score class 1 (p=0,001). After 24 months, a comparison revealed a significant diff erence between the two groups in arrhythmia symptoms (p=0,014), with maintaining the advantage of the BA ablation group. After 12 and 24 months, none of the patients in both compared groups had severe class IV angina.Conclusion. SF-36 parameters were improved 24 months after surgical treatment of CAD and long-standing persistent AF, regardless of the ablation strategy. Elimination of angina symptoms and long-term maintenance of sinus rhythm can improve the QOL of patients in the long-term postoperative period.

Predictors of atrial fibrillation recurrence after surgical ablation of long-standing persistent AF with concomitant coronary artery bypass grafting

Abstract Background A long-standing persistent form of atrial fibrillation (AF) in anamnesis, requiring surgical ablation together with coronary artery bypass surgery (CABG), significantly increases the risk of reccurence in the postoperative period. Before operation should consider the predictors of AF for long-term preservation of rhythm after surgery. Purpose To evaluate the predictors of AF recurrence on 3rd day and at discharge in patients after CABG with concomitant surgical ablation of long-standing persistent AF. Methods A prospective randomized single-center analysis was performed on patients with long-standing persistent AF, undergoing CABG with concomitant left atrial ablation (LAA) or biatrial ablation (BA) between 2016 and 2019. 116 patients were randomized into two groups: 58 in LAA+CABG, 58 in BA+CABG. The median age of the patients was 65 (IQR, 61 to 67.75) years in gr. BA and 62 (IQR, 58 to 66) in gr. LAA (Mann-Whitney U-test, p=0.050), 83% of men were in gr. BA (Fisher test, p&amp;gt;0.999). Predictors of AF development on day 3 were identified using multivariable logistic regression from the following baseline characteristics: myocardial infarction in anamnesis, time of artificial circulation, time of application of radiofrequency energy, the size of the left and right atrium, funcrional class of cardiac angina and heart failure, gender, age, acute cerebrovascular accident (CVA), additional intervention on the heart (operations for aortic aneurysm, mitral, aortic and tricuspid valves replacement), concomitant cardiovascular, respiratory, digestive and urogenital diseases. Results Using a multivariate model of logistic regression, the following significant predictors of arrhythmias on the 3rd day in gr. BA were included: additional intervention on the heart valves (OR 63.13, p=0.001); an increase in the functional class (FC) of chronic heart failure (CHF) NYHA by 1 (OR 40.06, p=0.018); a history of CVA (OR 9.13, p=0.026). The following significant predictors of AF reccurence on the 3rd day in gr.LAA were identified: an increase in the long axis of the right atrium by 1 cm (OR 3.05, p=0.006); an increase of the FC of cardiac angina by 1 (OR 7.11, p=0.011); in women (OR 7.14, p=0.017). In BA significant predictors of AF reccurence at discharge were: an increase in the long axis of the left atrium by 1 cm (OR4.86, p=0.015); reccurence of AF on the 3rd day (OR 17.45, p=0.005); 1 year increase in age (OR 1.24, p=0.023); the presence of diabetes (OR 47.67, p=0.002). In gr. LAA the predictors at discharge were: reccurence of AF on 3rd day (OR 38.35, p=0.001); a history of CVA increases the chances of arrhythmia (OR 210.83, p=0.032). Conclusion Number of clinical and functional characteristics of a patient may be predictors of AF. We examined the predictors of reccurence of AF after surgical ablation of long-standing persistent AF with concomitant CABG. Taking them into account when choosing the optimal strategy of treatment is important. Funding Acknowledgement Type of funding sources: None.

An off-pump biatrial mini-maze procedure for treatment of long-standing persistent atrial fibrillation

Abstract Background Surgical treatment has assumed a more prominent role in the therapy of atrial fibrillation (AF) with favorable efficiency and acceptable safety during the last decades. The traditional Cox-Maze procedure and Wolf Mini-Maze procedure focused on left atrial ablation. However, it is ubiquitous that patients with long-standing persistent atrial fibrillation (LSPAF) typically suffer from biatrial electrical and structural remodeling. The left atrial procedures are still not enough in patients with LSPAF. Purpose Herein, we aimed to introduce a modified biatrial off-pump ablation procedure based on the Wolf Mini-Maze procedure and to detect the safety and efficacy of the surgery for patients with LSPAF. Methods Between January 2016 and September 2020, 102 patients of LSPAF underwent our modified Mini-Maze procedure using bipolar radiofrequency ablation. Those patients firstly underwent a Mini-Maze procedure using Dallas lesion set, including video-assisted bilateral mini-thoracotomy, left atrial appendage excision, bilateral pulmonary vein isolation, ganglionic plexi evaluation and destruction, left atrial roof connecting lesion, and a linear lesion connecting this roofline to the root of the aorta at the junction of the left coronary and the non-coronary cusp. Secondly, a purse-string suture was performed on the right atrium, and then four ablation lesions were made to the superior vena cava, to the inferior vena cava, to the appendix of the right atrium, and to the tricuspid valve annulus from the purse-string suture point by the bipolar radiofrequency clamp. After the operation, the patients were followed up at an interval of 3, 6, 12 months, and every 1 year after that. Results No mortality No surgical re-exploration for bleeding. No permanent pacemaker implantation. 99 patients were free from LSPAF upon discharge. A follow-up at interval of 3, 6, 12, 24, 36, and 48 months showed a success rate free from LSPAF was 95.1% (97/102), 94.4% (85/90), 94.8% (73/77), 91.5% (54/59), 90.3% (28/31) and 100% (9/9), respectively Conclusions The modified biatrial Mini-Maze suggested a safe and feasible procedure. Early follow-up demonstrated an acceptable success rate free from AF. It might have the potential to become another option for clinical treatment of LSPAF. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): General Program of the National Natural Science Foundation of China Schematic of the procedure

Temporary prolongation of corrected QT interval after cardioneuroablation for functional bradyarrhythmias

Abstract Background There are controversial reports on QT interval response to ganglionic plexi ablation that are selectively targeted during cardioneuroablation (CNA) or occurs as collateral lesion during left atrial ablation procedures. Both shortening or prolongation of the heart-rate corrected QT interval (QTc) with therapeutic or safety implications were described. Purpose In this retrospective study, we investigated longitudinal changes of QTc after CNA. Methods The study included 108 patients (age: 39±12 years, 60% males) who underwent biatrial cardioneuroablation (radiofrequency time: 15.5±6.7 min) for symptomatic functional bradyarrhythmias. Surface ECG examinations were performed on the day before the CNA (N=108), 1 hour after the CNA (N=106), on the 1st post-ablation day (N=50), at the 3-month (N=99), and 1-year (N=63) follow-up visits. Automated measurements of QT interval were employed for the analysis. Four formulas (Bazett, Framingham, Fridericia, and Hodges) were used for the correction of QT interval to instant heart rate. Results QTc significantly prolonged immediately after the CNA with rapid return to baseline values (Figure and Table). This was particularly valid for QT correction by Framingham formula (and similarly for Fridericia and Hodges formulas). The QTc by Bazett formula, which is known to overestimate QT at higher heart rates, returned to baseline more slowly and incompletely. Several mechanisms may contribute to observed QTc dynamics: (1) direct effect of autonomic denervation with recovery phenomenon; (2) QT hysteresis with an extremely long time constant; or (3) artifact due to suboptimum QT correction to a substantial change of heart rate. Conclusions The study suggests that CNA produces acute prolongation of QTc interval with rapid decay and virtual normalization in 3 months. CNA in otherwise healthy subjects is not likely associated with substantial long-term risk of long-QT-associated arrhythmias. In the same way, we cannot confirm earlier observations of clinically significant QTc shortening effect of ganglionated plexi ablation. Funding Acknowledgement Type of funding sources: None. Figure 1Table 1

Concomitant real-time measurement and correlation of contact force to baseline local impedance and local impedance drops in RF ablation of left and right atrial procedures

Abstract Introduction Radiofrequency (RF) ablation is performed in various arrhythmias. Still, arrhythmia recurrence is a challenging problem, not only in atrial fibrillation (AF). One reason for arrhythmia recurrence is suspected to be due to remaining gaps. Measurement of local impedance (LI) and change of LI during RF application can be used as a predictor and surrogate for successful ablation. Another tool, used for the last couple of years, estimating sufficient tissue contact is provided by catheters with real-time contact force (CF) measurement. The new INTELLANAV STABLEPOINT™ catheter by Boston Scientific was recently introduced combing both strategies. We sought to investigate the parallel measurement and correlation of LI and CF in real-time during left atrial (LA) and right atrial (RA) procedures. Methods We included the first n=20 patients who underwent LA ablation for AF or atypical atrial flutter and n=7 patients who underwent RA procedures for atrial flutter or atrial tachycardia and analysed retrospectively procedural data. For every RF delivery RF duration, CF, baseline LI, minimal LI, LI drop, as well as minimal LI and LI drop after 5 and 10 sec was documented. Only RF deliveries with stable contact (ablation without delay) were included. We then correlated baseline LI to LI drop (maximum, after 5 sec, after 10 sec) and to the documented CF at baseline. Results A total of 27 procedures was analysed. In total, 777 RF deliveries (663 in LA, 114 in RA) were documented with a mean RF duration of 21.7 sec. Mean baseline LI was 148.4 Ω, minimal LI 130.6Ω, LI after 5 sec 135.0 Ω and LI after 10sec 132.5 Ω. Mean complete LI drop was 17.8 Ω (13.4 Ω after 5 sec, 15.8 Ω after 10 sec). Mean CF was 15.5g. We could see a significant positive correlation between average CF and LI drop (p&amp;lt;0.01) (figure 1A), as well as between average CF and LI drop after 5 sec (p&amp;lt;0.01) and after 10 sec (p&amp;lt;0.01). Also, for baseline LI we could see a significant strong positive correlation to LI drop (p&amp;lt;0.001) (figure 1B), LI drop after 5 sec (p&amp;lt;0.001) and after 10 sec (p&amp;lt;0.001). Baseline LI did not correlate to average CF. Baseline LI was significantly higher in RA, when compared to LA (152.5Ω vs. 147.7Ω; p&amp;lt;0.05). LI drop did not differ between RA and LA procedures (17.8Ω vs. 17.7Ω), whereas mean RF duration per RF application was significantly longer in LA compared to RA procedures (22.8sec vs. 15.3sec; p&amp;lt;0.001) and applied CF was also higher in LA compared to RA procedures (16.0Ω vs. 12.8Ω; p&amp;lt;0.001). Conclusion Parallel real-time measurement of LI and CF is providing further insights into ablation biophysics. Based on these results the CF values might provide a prediction of subsequent lesion formation. A combination with LI measurement seems to be useful to prevent insufficient lesions, predisposing to gap formation and associated with arrhythmia recurrence, but also to potentially guarantee a higher safety by visualizing the applied CF and consecutive LI drop. Funding Acknowledgement Type of funding sources: None. Figure 1

Use of a novel 4D intracardiac echocardiography catheter to guide interventional electrophysiology procedures

Standard two-dimensional (2D), phased-array intracardiac echocardiography (ICE) is routinely used to guide interventional electrophysiology (EP) procedures. A novel four-dimensional (4D) ICE catheter (VeriSight Pro, Philips) can obtain 2D and three-dimensional (3D) volumetric images and cine-videos in real-time (4D). The purpose of this study was to determine the early feasibility and safety of this 4D ICE catheter during EP procedures. The 4D ICE catheter was placed from the femoral vein in ten patients into various cardiac chambers to guide EP procedures requiring transseptal catheterization, including ablation for atrial fibrillation and left atrial appendage closure. 2D- and 3D-ICE images were acquired in real-time by the electrophysiologist. A dedicated imaging expert performed digital steering to optimize and postprocess 4D images. Eight patients underwent pulmonary vein isolation (cryoballoon in seven patients, pulsed field ablation in one, additional radiofrequency left atrial ablation in one). Two patients underwent left atrial appendage closure. High quality images of cardiac structures, transseptal catheterization equipment, guide sheaths, ablation tools, and closure devices were acquired with the ICE catheter tip positioned in the right atrium, left atrium, pulmonary vein, coronary sinus, right ventricle, and pulmonary artery. There were no complications. This is the first experience of a novel deflectable 4D ICE catheter used to guide EP procedures. 4D ICE imaging is safe and allows for acquisition of high-quality 2D and 3D images in real-time. Further use of 4D ICE will be needed to determine its added value for each EP procedure type.

Short-term outcomes of surgical atrial ablation and septal myectomy

Background. Hypertrophic cardiomyopathy is one of the most common types of cardiomyopathy. The appearance of atrial fibrillation in patients with hypertrophic obstructive cardiomyopathy is associated with significant clinical worsening. Outcomes of surgical ablation and septal myectomy in these patients are limited.Aim. This retrospective study aimed to evaluate short-term outcomes of concomitant surgical ablation and septal myectomy in patients with obstructive hypertrophic cardiomyopathy and atrial fibrillation.Methods. Fifty-five patients with hypertrophic obstructive cardiomyopathy and atrial fibrillation who underwent concomitant surgical ablation and septal myectomy between 2014 and 2019 were analysed. Patients with paroxysmal atrial fibrillation predominantly underwent left atrial ablation, and those with nonparoxysmal atrial fibrillation predominantly underwent the Maze IV procedure. Surgical ablation was performed using cryoablation alone (83.6%) or in combination with radiofrequency energy (16.4%).Results. Hospital mortality was 1.8%. Incidence of major adverse events was 3.6%. Sinus node dysfunction and atrioventricular block occurred in 7.3% and 1.8% of patients, respectively. Bleeding requiring revision occurred in 2 (3.6%) patients. Forty-nine (89.1%) patients had stable sinus rhythm and five (9.1%) were on dual-chamber pacemaker stimulation at the time of discharge.Conclusion. Concomitant septal myectomy and surgical ablation are feasible and safe in patients with hypertrophic obstructive cardiomyopathy and atrial fibrillation.Received 5 April 2021. Revised 16 May 2021. Accepted 17 May 2021.Funding: The study did not have sponsorship.Conflict of interest: The authors declare no conflicts of interests.Contribution of the authorsConception and study design: A.S. Zalesov, A.V. Bogachev-ProkophievData collection and analysis: A.S. Zalesov, S.A. Budagaev, A.V. SapeginStatistical analysis: A.S. Zalesov, A.V. Afanasyev, R.M. SharifulinDrafting the article: A.S. ZalesovCritical revision of the article: A.V. Bogachev-Prokophiev, S.I. Zheleznev, I.I. DeminFinal approval of the version to be published: A.S. Zalesov, A.V. Bogachev-Prokophiev, A.V. Afanasyev, R.M. Sharifulin, A.V. Sapegin, S.A. Budagaev, S.I. Zheleznev, I.I. Demin

Risk Factors for Stiff Left Atrial Physiology 1 Year After Catheter Ablation of Atrial Fibrillation.

Catheter ablation is the most effective rhythm control method for patients with atrial fibrillation (AF); however, it inevitably causes atrial tissue damage. We previously reported that AF catheter ablation (AFCA) increases left atrial (LA) pressure without changes in symptom scores. We hypothesized that extensive LA ablation increased the risk of stiff LA physiology. We included 1,720 patients (69.1% male, 60.0 [53.0–68.0] years old, 66.2% with paroxysmal AF) who underwent de novo AFCA and echocardiography before and 1-year after the procedure. Stiff LA physiology was defined, when the amount of the estimated pulmonary arterial pressure increase between the pre-procedural and the 1-year post-procedural follow-up echocardiography was >10 mmHg and when right ventricular systolic pressure (RVSP) was >35 mmHg at 1-year follow-up echocardiography. The failed rhythm control within 1 year was defined as recurrent AF despite using anti-arrhythmic drugs or cardioversion within a year of AFCA. We explored the incidence and risk factors for stiff LA physiology and the rhythm outcome of AFCA. Among the 1,720 patients, 64 (3.7%) had stiff LA physiology 1 year after AFCA. Stiff LA physiology was independently associated with diabetes (odds ratio [OR], 2.36 [95% CI, 1.14–4.87], p = 0.020), the ratio of the peak mitral flow velocity of the early rapid filling to the early diastolic velocity of the mitral annulus (E/Em; OR, 1.04 [95% CI, 1.00–1.10], p = 0.049), LA pulse pressure (Model 2: OR, 1.05 [95% CI, 1.00–1.11], p = 0.049), low LA voltage (OR, 0.36 [95% CI, 0.18–0.74], p = 0.005), empirical extra-pulmonary vein (PV) LA ablation (OR, 2.60 [95% CI, 1.17–5.74], p = 0.018), and radiofrequency (RF) ablation duration (Model 2: OR, 1.02 [95% CI, 1.01–1.03], p = 0.003). Although the incidence of post-AFCA stiff LA physiology was 3.7% and most of the cases were subclinical, the empirical extra-PV ablation was associated with this undesirable condition. In addition, patients who had low mean LA voltage before AFCA could be susceptible to stiff LA physiology.

Thoracoscopic surgical atrial fibrillation ablation in patients with an extremely enlarged left atrium

PurposeEfficacy of pulmonary vein isolation (PVI) for atrial fibrillation (AF) decreases as left atrial (LA) volume increases. However, surgical AF ablation with unknown efficacy is being performed in patients with a giant LA (GLA). We determined efficacy of thoracoscopic AF ablation in patients with compared to without a GLA.MethodsPatients underwent thoracoscopic PVI with additional left atrial ablations lines (in persistent AF) and were prospectively followed up. GLA was defined as LA volume index (LAVI) ≥ 50 ml/m2. Follow-up was performed with ECGs and 24-h Holters every 3 months. After a 3-month blanking period, all antiarrhythmic drugs were discontinued. The primary outcome was freedom of any atrial tachyarrhythmia ≥ 30 s during 2 years of follow-up.ResultsAt baseline, 68 (15.4%) patients had a GLA (LAVI: 56.7 [52.4–62.8] ml/m2), while 374 (84.6%) had a smaller LA (LAVI: 34.8 [29.2–41.3] ml/m2). GLA patients were older (61.9 ± 6.9 vs 59.4 ± 8.8 years, p = 0.02), more often diagnosed with persistent AF (76.5% vs 58.6%, p = 0.008). Sex was equally distributed (with approximately 25% females). GLA patients had more recurrences compared to non-GLA patients at 2-year follow-up (42.6% vs 57.2%, log rank p = 0.02). Freedom of AF was 69.0% in non-GLA paroxysmal AF patients compared to 43.8–49.3% in a combined group of GLA and/or persistent AF patients(log rank p < 0.001). Furthermore, freedom was 62.4% in non-GLA male patients, compared to 43.8–47.4 in a combined group of GLA and/or female sex(log rank p = 0.02).ConclusionThoracoscopic AF ablation is an effective therapy in a substantial part of GLA patients. Thoracoscopic AF ablation may serve as a last resort treatment option in these patients.

Long-Term Outcomes of Surgical Ablation for Atrial Fibrillation: Impact of Ablation Lesion Sets.

The lesion sets for surgical ablation of atrial fibrillation (AF) that provide optimal outcomes have remained controversial. We evaluated the effects of left-atrial (LA) ablation of AF compared with bi-atrial (BA) ablation on the clinical and rhythm outcomes, and examined the predictors for AF recurrence and permanent pacing in consideration of ablation lesion sets. Between 2001 and 2018, 1,965 patients underwent surgical ablation during cardiac surgery at our institution. Among these, 796 and 1,169 patients underwent LA and BA ablation, respectively. The clinical outcomes were evaluated after propensity score adjustment, with death accounting for a competing event. The probability of AF recurrence was estimated with the generalized estimating equations model. The patients with BA ablation had morbidities greater than those with LA ablation. The probability of AF recurrence at 1 and 5 years was 13.9% and 37.1% in patients with LA ablation, and 11.2% and 30.1% in those with BA ablation (hazard ratio [HR]: 1.24; 95% confidence interval [CI]: 0.96-1.61; P=0.100). After adjustment, LA ablation was associated with a decreased risk of early death (<30days) (odds ratio [OR]: 0.56; 95%CI: 0.31-0.96; P=0.041) and new-onset dialysis (OR 0.47; 95%CI: 0.27-0.78; P=0.003). However, the risk of overall mortality (HR: 1.03; 95%CI: 0.75-1.41; P=0.878) and permanent pacing (HR: 0.68; 95%CI: 0.43-1.06; P=0.091) was comparable between the 2groups. The risk of AF recurrence and adverse events was comparable between the 2 ablation lesion sets. BA ablation was not related to an increased risk of permanent pacing.

Repeat procedures for recurrent persistent atrial fibrillation: A propensity-matched score comparison between left atrial linear ablation with radiofrequency and posterior wall isolation with the cryoballoon.

AimsTo evaluate the clinical outcome in patients undergoing repeat procedures for recurrent persistent atrial fibrillation following an index cryoballoon (CB‐A) pulmonary vein isolation ablation on a mid‐term follow‐up of 12 months.MethodsIn this propensity score‐matched comparison, 50 patients undergoing left atrial posterior wall isolation (LAPWI) with the CB‐A were matched to 50 patients treated with additional linear ablation using radiofrequency catheter ablation (RFCA).ResultsMeantime to repeat the procedure was 9.74 ± 4.36 months. At 12 months follow‐up freedom from atrial tachyarrhythmias (ATas) was achieved in 82% of patients in the LAPWI group and in 62% of patients in the linear ablation group (P = .03). Regression analysis demonstrated that relapses during the blanking period and LA dimensions were independent predictors of ATas recurrences following the repeat procedure.ConclusionLAPWI using CB‐A is associated with a significantly higher freedom from atrial arrhythmias when compared with the RFCA mediated left atrial linear lesions on a mid‐term follow‐up of 12 months in patients with persAF undergoing a redo procedure.

Post-ablation left atrial function impacts long-term recurrence of atrial fibrillation after ablation.

Left atrial (LA) function can help predict various cardiovascular events. Catheter ablation for atrial fibrillation (AF) modifies baseline LA function through the maintenance of sinus rhythm and myocardial injury. We investigated the impact of post-ablation LA function on recurrence of AF after ablation and identified the predictors of reduced post-ablation LA function. A total of 616 patients who underwent AF ablation (paroxysmal, N = 310; non-paroxysmal, N = 306) were retrospectively examined with cardiac computed tomography at baseline and 3months after the final ablation procedure. Post-ablation LA emptying fraction (LAEFpost) was calculated. We evaluated the association between LAEFpost and recurrence of AF after the final ablation procedure. Further, we assessed the predictors of reduced LAEFpost. The recurrence rate of AF was 72.7% after the final ablation procedure [median follow-up 48months (48.0, 48.0), total number of ablation sessions: 1.4 ± 0.7]. Multivariate analysis revealed that LAEFpost was associated with the recurrence of AF (hazard ratio/10% increase: 0.62, 95% confidence interval: 0.51-0.75, P < 0.0001). LAEFpost had a mild predictive power for recurrence of AF (c-statistics: 0.670, optimal cutoff: 26.36%, P < 0.0001). The recurrence-free proportion among patients with reduced LAEFpost (< 26.36%, N = 100) and those with preserved LAEFpost (≥ 26.36%, N = 516) was 40% and 79%, respectively (P < 0.0001). The predictors of reduced LAEFpost were low pre-ablation LAEF, high pre-ablation LA volume, low body mass index (BMI), and female sex. Further, reduced LAEFpost was associated with the total number of ablation sessions and extra-pulmonary vein LA ablation. In conclusion, reduced LAEFpost was associated with recurrence of AF after ablation. Advanced LA remodeling, low BMI, and female sex could predict reduced LAEFpost. Although additional ablation was associated with reduced LAEFpost, it remains unclear whether reduced LAEFpost resulted from the additional ablation. Reduced LAEFpost might help stratify patients with ablation-refractory AF.

B-PO05-093 VALIDATION OF A NEW ABLATION INDEX PROTOCOL FOR LEFT ATRIAL LINEAR ABLATION

Standardized contiguous and optimized radiofrequency ablation encircling ipsilateral pulmonary veins (PV) with high incidence of first-pass isolation has been established with the CLOSE protocol. In this study, we evaluated the acute outcome of a specific ablation index protocol for left atrial (LA) linear ablation. This prospective study comprised 81 patients (age: 67±14 y, male: 52 %) undergoing de-novo ablation for persistent atrial fibrillation (AF) or patients requiring substrate ablation beyond PV isolation. We hypothesized that point-by-point ablation with an ablation index of 600 for the anterior line and 500 for the roof line and an interlesion distance <6mm will result in a high rate of first-pass block. Touch-up ablation was performed in case of incomplete line block. Line integrity was evaluated with a high-density mapping catheter (Pentaray) and the coherent activation mapping tool (CARTO3 V7) during LAA pacing and differential pacing maneuver. First-pass block of the roof line was achieved in 70 (92 %) patients, while another 5 (7 %) patients required additional touch-up ablation to complete the line, resulting in a total of 75 (99 %) blocked roof lines. A first-pass anterior line block was observed in 47 (69 %) patients. An additional 17 (25 %) patients required touch-up ablation for block achievement, resulting in a total of 64 (94 %) blocked anterior lines. For the anterior line, the Bachmann bundle insertion was identified as the predominant location of gaps. The mean ablation index of roof line ablation was 512±14 and 610±13 in anterior line ablation. The mean overall procedure and fluoroscopy time was 136±30 min and 7.2±3.8 min, respectively. The mean RF ablation time for roof line was 8±5.4 min and for anterior line 14±5.9 min. Baseline rhythm was AF in 46 patients, which terminated by linear ablation in 19 (41%) patients. This new standardized Ablation Index protocol accomplishes first-pass block of left atrial linear lesions in the vast majority of patients. Furthermore, with additional touch-up ablation at gap sites, line block was achieved in almost all patients.

B-PO02-117 PERICARDIAL EFFUSIONS DURING LEFT ATRIAL ABLATION PROCEDURES IN PATIENTS RECEIVING NON-WARFARIN ORAL ANTICOAGULANTS: MANAGEMENT AND OUTCOMES

An increasing number of left atrial ablation procedures are being performed on patients receiving non-warfarin oral anticoagulants (NOACs), often uninterrupted. Little has been reported on the management and outcomes of pericardial effusion in the setting of NOAC use. To evaluate the characteristics and outcomes of procedure-related pericardial effusion while taking NOACs. We performed a single-center retrospective review of all left atrial catheter ablation procedures between 2017 and 2020. Data collection included patient demographics, procedure type, pre-procedural anticoagulation strategies, peri-procedural management, and outcomes. Of the 2192 ablation procedures performed, 22 pericardial effusions occurred (1.0%), of which 21 occurred in patients taking NOACs (Apixaban in 15, Rivaroxaban in 6) - uninterrupted in 15 (71.4%; see Table). Pericardiocentesis was performed in 20 of 21 patients (95.2%), either intraoperatively (n=16) or for delayed effusion (n=5); repeat pericardiocentesis was required in 3 patients (14.3%). Reversal agents were frequently used: protamine (n=12) and prothrombin concentrate complex (n=7). Additional management strategies included covered stent implant for CS perforation (n=2) and Amplatzer plug implant for LA wall perforation (n=1). Surgery was not required, and there were 0 strokes and deaths. Median length of hospital stay was 3 days (range 1-12). Left atrial ablation procedure-related pericardial effusion on NOACs can be managed without surgical intervention. Novel NOAC-specific reversal agents may further streamline management.

B-PO02-203 ESOPHAGEAL PERFORATION FOLLOWING RADIOFREQUENCY CATHETER ABLATION FOR ATRIAL FIBRILLATION: A CONSERVATIVE APPROACH

A rare complication of radiofrequency ablation for atrial fibrillation is esophageal perforation which is usually treated surgically. N/A N/A A 74-year-old woman presented with dysphagia and odynophagia 1 week following an uncomplicated radiofrequency ablation for AF. The patient had a history of diabetes mellitus, dyslipidemia and recurrent paroxysmal AF refractory to drugs. The patient was normotensive and afebrile, but her laboratory tests showed a white blood cell count of 11K and CRP of nearly 60 mg/L. Cardiac examination was unremarkable. A chest CT and EGD were obtained and revealed an esophageal perforation (Figure 1A) without atrial or pericardial involvement. In the ICU, she was made NPO and started on parenteral nutrition, broad spectrum antibiotics for 7 days, and proton pump inhibitor therapy. Post-ablation anticoagulation was continued with IV heparin. Based on the patient’s clinical stability she was treated with a conservative approach with close observation. On day 7 another CT and EGD were performed and showed two esophageal injuries (Figure 1B) with ulceration and fibrin around the injury. After 22 days the patient had no worsening of her clinical condition. Subsequent EGD showed a complete healing of one of the injuries and a closure of about 50% of the damaged area with granulation tissue (Figure 1C). On day 46 day an EGD showed a complete healing of the esophageal injury (Figure 1D) and the patient was discharged. At 1-year follow up the patient presented in good condition and without any associated symptoms. In selected patients esophageal perforation following left atrial ablation can be treated without surgery.