Endocardial Ablation Research Articles

Abstract 12991: Staged Hybrid Convergent Procedure for Persistent Atrial Fibrillation: Single Center Outcomes From a Community Hospital

Introduction: Hybrid-Convergent procedure(HCP) has been recently approved for treatment of persistent atrial fibrillation(AF). This was studied as a same day procedure which posed significant scheduling challenges with regards to procedure space and personnel. Staging the procedure was more convenient in smaller and busy Community Hospitals like ours. We report our experience with Staged HCP. Methods: We retrospectively analyzed all patients who underwent HCP at our Hospital from January 1,2017 to December 31,2020. Same day HCP were excluded. Outcomes at 6 month and 1 year follow up after the procedure were analyzed. Results: A total of 29 patients with persistent AF underwent Staged HCP. The mean age was 62.3 years with 75.86% being men. Periprocedural and 30 day mortality was 0%. The mean time between epicardial ablation and endocardial ablation was 46.15 days (SD :17.5 days, interquartile range 6-78). Freedom from AF (normal sinus rhythm on electrocardiograms and/or <1% AF burden on >24 hour monitoring) was seen in 77.78% and 88% patients at 6 months and 1 year respectively. Success of procedure (freedom from AF with maintenance as before procedure, decrease in dose of or complete cessation of Class I/III anti-arrhythmic drug) was seen in 70.4% and 76% at 6 months and 1 year respectively. The de-escalation in treatment (complete cessation or dose reduction of Class I/III anti-arrhythmic drug) at 6 month and 1 year follow up was seen in 57.14% and in 54.55% patients respectively. Conclusions: Staged HCP can be done safely with excellent outcomes on par with results seen in the CONVERGE Clinical Trial

Abstract 13439: Long-Term Outcomes From Continuous Rhythm Monitoring After Hybrid Convergent Procedure in Longstanding Persistent Atrial Fibrillation Patients

Introduction: Endocardial catheter ablation has suboptimal effectiveness and durability in patients with longstanding persistent atrial fibrillation (LSPAF). Hybrid convergent ablation combines epicardial and endocardial ablation to create a transmural lesion set that isolates the left atrial posterior wall and pulmonary veins. The study objective was to evaluate long-term outcomes assessed by continuous rhythm monitoring in LSPAF patients who received hybrid convergent ablation. Methods: This was a single-center IRB-approved, observational study. Eligible patients were identified by retrospective chart review and included patients who received hybrid convergent procedures between September 2011 and November 2017. Patients were consented for prospective long-term follow-up visits and continuous cardiac monitoring (7-day ePatch). Baseline characteristics, procedural outcomes, and follow-up data were entered into the TRAC-AF registry. This analysis focused on the patient subgroup with pre-operative LSPAF (AF duration >1 year). Results: Of 77 consented patients, 60 had pre-operative LSPAF. Mean age was 66.1 ± 7.9 years, 70% were male, and duration of AF was 6.8 ± 4.8 years. Mean CHA2DS2-VASc score was 2.6 ± 1.4; mean BMI was 32.1 ± 5.9, and 55% (33/60) of patients had previous catheter ablation. Thirty-day major adverse event rate was 5% (3/60) and included 2 inflammatory pericardial effusions and one major bleeding. On continuous monitoring, 71% (41/58) of patients had 0% AF burden at mean follow-up of 61.7 ± 18.9 months. Eight patients (13%) had repeat catheter ablation at mean 21.6 ± 16.3 months since index procedure. Comparison of baseline and follow-up left ventricular ejection fraction (LVEF) from echocardiography revealed a trend of 12.4 ± 13.0 units improvement at mean follow-up of 18.2 ± 23.7 months since baseline in 5 patients with severely reduced (<40%) baseline ejection fraction (p=0.063). Conclusions: Long-term follow-up with continuous monitoring revealed a majority of patients with pre-operative LSPAF had 0% AF burden after a mean 61.7 months since the hybrid convergent procedure. These results are aligned with published studies and the CONVERGE trial on the effectiveness of hybrid convergent ablation in LSPAF.

Hybrid convergent ablation versus endocardial catheter ablation for atrial fibrillation: A systematic review and meta-analysis.

IntroductionEndocardial catheter ablation (ECA) for atrial fibrillation (AF) has limited efficacy. Hybrid convergent procedure (HCP) with both epicardial and endocardial ablation is a novel strategy for AF treatment. In this meta‐analysis, we aimed to evaluate the efficacy and safety of HCP in AF ablation.MethodWe performed a comprehensive literature search for studies that evaluated the efficacy and safety of HCP compared with ECA for AF. The primary outcome was freedom of atrial arrhythmia (AA). The secondary outcome was the periprocedural complication rate. Pooled relative risk (RR) and corresponding 95% confidence intervals (CIs) were calculated using the random effects model.ResultsA total of eight studies, including 797 AF patients (mean age: 60.7 ± 9.8 years, 366 patients with HCP vs. 431 patients with ECA alone), were included. HCP showed a higher rate of freedom of AA compared with ECA (RR: 1.48, 95% CI: 1.13–1.94, p = .004). However, HCP was associated with higher rates of periprocedural complications (RR: 3.64, 95% CI: 2.06–6.43; p = .00001). Moreover, the HCP had a longer procedure time and postprocedural hospital stay.ConclusionsAlthough hybrid ablation was associated with a higher success rate, this should be judged for increased periprocedural adverse events and extended hospital stay. Prospective large‐scale randomized trials are needed to validate these results.

Epicardial course of the musculature related to the great cardiac vein: Anatomical considerations and clinical implications for mitral isthmus block after vein of Marshall ethanol infusion.

Mitral isthmus gaps have been ascribed to an epicardial musculature anatomically related to the great cardiac vein (GCV) and the vein of Marshall (VOM). Their lumen offers an access for radiofrequency application or ethanol infusion, respectively. The purpose of this study was to evaluate the frequency of mitral isthmus gaps accessible via the GCV lumen, to assess their location around the GCV circumference, and to propose an efficient ablation strategy when present. One hundred consecutive patients underwent VOM ethanol infusion (step 1) and endocardial linear ablation from the mitral annulus to the left inferior pulmonary vein (step 2). In cases of mitral isthmus gap, endovascular ablation of the GCV anchored wall facing the left atrium was systematically performed (step 3), while the opposite GCV free wall was targeted in case of block failure only (step 4). After VOM ethanol infusion and endocardial ablation, mitral isthmus block occurred in 51 patients (51%). Pacing maneuvers and activation sequences demonstrated an epicardial gap via the VOM in 2 patients (2%) and via the GCV in 47 patients (47%). In the latter case, block was achieved at the GCV anchored wall in 42 patients (89%) and the GCV free wall in 5 patients (11%). Global success rate of mitral isthmus block was 98%. No tamponade occurred. With the advent of VOM ethanol infusion, residual mitral isthmus gaps are mostly eliminated within the first centimeter of the GCV. Thorough mapping of the entire circumference of the GCV wall can help identify these epicardial gaps.

Ventricular tachycardia ablation in nonischemic cardiomyopathy

Abstract Introduction Catheter ablation outcomes for drug-resistant ventricular tachycardia (VT) in nonischemic cardiomyopathy (NICM) are suboptimal when compared to ischemic cardiomyopathy. We aimed to analyse the long-term efficacy and safety of percutaneous catheter ablation in this subset of patients. Methods Single-center observational retrospective registry including consecutive NICM patients who underwent catheter ablation for drug-resistant VT during a 10-year period. The efficacy endpoint was defined as VT-free survival after catheter ablation, while safety outcomes were defined by 30-days mortality and procedure-related complications. Independent predictors of VT recurrence were assessed by Cox regression. Results In a population of 68 patients, most were male (85%), mean left ventricular ejection fraction (LVEF) was 34±12%, and mean age was 58±15 years. All patients had an implantable cardioverter-defibrillator. Twenty-six (38%) patients underwent epicardial ablation (table 1). Over a median follow-up of 3 years (IQR 1–8), 41% (n=31) patients had VT recurrence and 28% died (n=19). Multivariate survival analysis identified LVEF (HR= 0.98; 95% CI 0.92–0.99, p=0.046) and VT storm at presentation (HR=2.38; 95% CI 1.04–5.46, p=0.041) as independent predictors of VT recurrence. The yearly rates of VT recurrence and overall mortality were 21%/year and 10%/year, respectively. No patients died at 30-days post-procedure, and mean hospital length of stay was 5±6 days. The complication rate was 7% (n=5, table 1), mostly in patients undergoing epicardial ablation (4 vs 1 in endocardial ablation, P=0.046). Conclusion LVEF and VT storm at presentation were independent predictors of VT recurrence in NICM patients after catheter ablation. While clinical outcomes can be improved with further technical and scientific development, a tailored endocardial/epicardial approach was safe, with low overall number of complications and no 30-days mortality. Funding Acknowledgement Type of funding sources: None.

Electrophysiological predictors of ventricular tachycardia recurrence in patients with structural heart disease after combined endo-epicardial substrate catheter ablation

Abstract Background Although there is a tremendous improvement in mapping and ablation techniques over the last decades, the recurrence rate of ventricular tachycardia (VT) in patients with structural heart diseases following endo-epicardial catheter ablation remains high. Purpose To determine predictors of VT recurrence in patients with structural heart disease after combined endo-epicardial radiofrequency (RF) VT ablation. Methods This prospective single-center study included 39 patients (34 men and 5 women, mean age 49.6±16.0 years), who underwent endo-epicardial mapping and ablation of the VT substrate. Etiology of structural heart diseases included: previous myocardial infarction (n=15); non-ischemic cardiomyopathy (n=24: 15 – arrhythmogenic right ventricular cardiomyopathy (ARVC), 6 – myocarditis, 3 – unspecified). First-line epicardial access was performed in 16 patients, as a second approach – in 23 subjects. We evaluated total ventricular myocardial areas, epi- and endocardial areas with bipolar low voltage (<1.5mV), scar area (bipolar <0.5mV), and unipolar low voltage (<5.0mV) and transient (<8.0mV) areas; areas of late potential registration were evaluated. Ratios of transient, low amplite and late-potential areas were calculated for endo- and epicardial surfaces, bipolar and unipolar maps. The following procedural electrophysiology characteristics were considered: inducibility of clinical VT, the number and morphology of induced VT, QRS width on sinus rhythm and VT, tachycardia cycle length, pseudo-delta wave extant and width, internal activation time, intrisicoud deflection time, and RS length. Clinical data such as echocardiography parameters, comorbidity and antiarrhythmic drug therapy were also taken into account. VT recurrences were documented using ICD/CRT-D interrogation, event ECG monitoring. Follow-up included mandatory visits at 6 and 12 months and unscheduled visits. Results Epicardial late potentials were registered in 69% of cases before ablation. Epicardial RF applications were delivered in 67% of patients; while only endocardial RF applications (including cases with intended epicardial substrate modification by endocardial ablation) were present in 28% cases. Non-inducibility of any VT plus abatement of local abnormal electrical activity was achieved in 32 (82%) of cases. The ratio epi/endo bipolar areas <0.5mV was much higher in patients with vs without VT recurrence at 6 months (4.3 (IQR: 2.5; 8.2) vs 0.75 (IQR:0.4; 1.6), P=0.001). A strong negative correlation was found between the induced VT cycle length and the ratio epi/endo bipolar areas <0.5mV: the shorter induced VT cycle length -the larger the area of the epicardial low voltage area (r=−0,52). Conclusion Regardless of epicardial substrate modification, patients with a larger epicardial low voltage area are more likely to have VT recurrence at 6 months after index ablation. A shorter induced VT cycle length is associated with a larger epicardial low-voltage area. Funding Acknowledgement Type of funding sources: None.

Rotational activity presence and its impact in persistent atrial fibrillation follow-up

Abstract Introduction Treatment of atrial fibrillation (AF) remains sub-optimal, with low success in pulmonary vein isolation (PVI) ablation procedures in long-standing-persistent AF patients. The maintenance mechanisms of AF are still under debate. Rotational activity (RA) events, also known as rotors, may play a role in perpetuating AF. The characterisation of these drivers during electroanatomical (EA) guided ablation procedures in relationship with follow-up and recurrence ratios in AF patients is necessary to design new ablation strategies to improve the AF treatment success. Purpose We report an AF patient cohort of endocardial mapping and PVI ablation procedures with additional RA events detected during the EA study. We aim to study the presence and distribution of RA in AF patients and its impact on AF recurrence when only PVI ablation is performed. Methods 75 persistent consecutive AF patients (age 60.7±9.8, 74.7% men) underwent EA mapping and RA detection with an automatic algorithm. The presence of RA was annotated on the EA map based on the unipolar electrograms (EGMs) registered with a 20-pole catheter. RA presence was analysed at different left atrial locations (37.2±14.8 sites per patient). AF recurrence was evaluated in follow-up after treatment. Results At follow-up (9±5 months), 50% of the patients presented AF recurrence. Patients with RA had more dilated atria in terms of volumes (p=0.002) and areas (p=0.001). Patients with RA exhibited higher mean voltage EGMs 0.6±0.3 mV vs 0.5±0.2 mV (p=0.036), with shorter cycle lengths 169.1±26.0 ms vs. 188.4±44.2 ms (p=0.044). Finally, patients with RA presented more AF recurrence rates than patients with no RA events (p=0.007). No significant differences were found in terms of comorbidities, e.g., heart failure, hypertension, COPD, stroke, SHD, or diabetes mellitus. Conclusions The results show that patients with more RA events and those with RA outside the PVI ablated regions presented higher AF recurrence episodes than those with no RA or events inside the areas affected by radio-frequency ablation. The study suggests that further ablation treatment of the areas harboring RA might be necessary to reduce the recurrence ratio in AF patients. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Instituto de Salud Carlos III; Sociedad Española de Cardiología

Long-term outcome of endocardial-only versus combined endocardial-epicardial homogenization of the scar for treatment of ventricular tachycardia in patients with ischemic cardiomyopathy

Abstract Introduction We investigated the ablation success of scar homogenization with combined (epicardial + endocardial) versus endocardial-only approach for ventricular tachycardia (VT) in patients with ischemic cardiomyopathy (ICM) at 5 years of follow-up. Method Consecutive ICM patients undergoing VT ablation at our center were classified into group 1: endocardial scar homogenization and group 2: endocardial +epicardial scar homogenization. Patients with previous open heart surgery were excluded. All patients underwent bipolar substrate mapping with standard scar settings defined as normal tissue >1.5 mV and severe scar <0.5 mV. Non-inducibility of monomorphic VT was the procedural endpoint in both groups. Patients were followed up twice a year for 5 years with implantable device interrogations. Results A total of 361 (Group 1: 291 and group 2: 70) patients were included in the study (mean age: 67 years, male: 88.4%). At 5 years, significantly higher number of patients from group 2 remained arrhythmia-free (figure 1). Of those patients, 87 (45%) and 51 (89%) from group 1 and 2 respectively were off-anti-arrhythmic drugs (AAD) (p<0.001). After adjusting for age, gender, hypertension, diabetes, and obstructive sleep apnea, scar homogenization using endo-epicardial approach was associated with 51% less recurrence compared to the endocardial ablation strategy (Hazard Ratio: 0.49, 95% CI: 0.27–0.89, p: 0.02). Conclusion In this series of patients with ischemic cardiomyopathy and VT, endo-epicardial scar homogenization was associated with a lower need for AAD and a significantly lower recurrence rate at 5-years of follow-up compared to the endocardial ablation alone. Funding Acknowledgement Type of funding sources: None. Figure 1

Mutation in a non-desmosomal gene is associated with poor outcome of endo-epicardial ventricular tachycardia ablation in patients with nonischaemic cardiomyopathy

Abstract Background Nonischaemic cardiomyopathy (NICM) represents a heterogenic disorder with a variable arrhythmogenic substrate. Its location is often epicardial and catheter ablation in this location proved to be an effective therapeutic modality in NICM patients with recurrent ventricular tachycardias (VTs). Purpose To determine the impact of the type of genetic mutation on the long-term outcome of endo-epicardial ablation in patients with NICM. Methods We investigated 82 patients (age 47±15 years, 10 women) with NICM who underwent endo-epicardial ablation for frequent VTs. Of them, 59% had a history of failed endocardial ablation. Patients had a left ventricular ejection fraction of 44±14% and all were implanted with cardioverter-defibrillator. One hundred candidate genes were examined using the new generation sequencing technique. Results Mutation in genes coding desmosomal complex (genes: PKP2, DSC, DSP, and DSG) was found in 30% of patients (“desmosomal” group). In 23% of patients, other gene mutations (genes: LMNA/C, MYH7, DES, TTN, RYR2, TPM1, MYPN, FLNC, and SCN5A) were detected (“non-desmosomal” group). In 46% of subjects no pathogenic mutation could be identified (“none” group). During a mean follow up of 34±33 months, patients in the “non-desmosomal” group were at significantly higher risk of VT recurrence and death/heart transplant compared to patients in the “desmosomal” group (Figure 1). Conclusion Potentially pathogenic mutation can be detected in about half of patients with NICM undergoing endo-epicardial VT ablation. Most commonly, mutations can be found in genes coding desmosomal complex and the endo-epicardial ablation is then associated with a satisfactory low VT recurrence rate and excellent survival in the long-term. On the other hand, patients with a mutation in non-desmosomal genes have poor outcomes despite endo-epicardial ablation. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Supported by Ministry of Health of the Czech Republic, grant nr. NV18-02-00237 Figure 1

Zero-fluoroscopy ablation for cardiac arrhythmias: A single-center experience in Japan.

BackgroundExposure to radiation during catheter ablation procedures poses a risk to the heath of both the patient and electrophysiology laboratory staff. Recently, the feasibility and effectiveness of zero‐fluoroscopy ablation have been reported. However, studies on the outcomes of zero‐fluoroscopy ablation in Japan remain limited. This study investigated the outcomes of zero‐fluoroscopy ablation for cardiac arrhythmias at a Japanese institute.Methods and ResultsWe present a retrospective analysis of the safety, efficacy, and feasibility data from 221 consecutive patients who underwent zero‐fluoroscopy ablation. Of these patients, 181 had atrial fibrillation, 17 had paroxysmal supraventricular tachycardia, 13 had atrial tachycardia, 6 had ventricular tachycardia, and 4 had ventricular premature contractions. We performed zero‐fluoroscopy ablation using three‐dimensional electro‐anatomical mapping systems and intracardiac echocardiography imaging. Ultrasound‐guided sheath insertion was performed on all cases. Our experience includes exclusively endocardial cardiac ablations. The mean follow‐up was 24 months. The recurrence rates were 25.4% for atrial fibrillation, 5.9% for paroxysmal supraventricular tachycardia, 15.4% for atrial tachycardia, 33.3% for ventricular tachycardia, and 25% for ventricular premature contraction. Complications occurred in two patients (0.9%), and there was no occurrence of death. A fluoroscopic guide was used in three cases for the confirmation of vascular access (one case) and for complications (two cases).ConclusionsZero‐fluoroscopy ablation was routinely performed without compromising on safety and efficacy. This approach may eliminate the exposure to radiation for all individuals involved in this procedure.

Role of endocardial ablation in eliminating an epicardial arrhythmogenic substrate in patients with Brugada syndrome.

Epicardial ablation is occasionally limited by coronary artery (CA) injuries or epicardial fat (EF). The purpose of this study was to evaluate the anatomic obstacles that prevent ablation of epicardial abnormal potentials (EAPs) in patients with Brugada syndrome (BrS) and to investigate the feasibility of EAP elimination by endocardial right ventricular (RV) ablation. This study included 16 BrS patients with previous ventricular fibrillation (VF), including 10 with an electrical storm. Data from multidetector computed tomography were assessed, and the proximity of the CA and EF was correlated with EAPs. EAPs were present in the epicardial RV outflow tract and RV inferior wall in all patients and 12 patients (75%), respectively. These EAPs were present within 5 mm of the main body and branches of the right CA in 14 patients (87.5%). However, only 1.4% ± 2.9% of the EAP area was covered with thick EF (≥8 mm). Partial EAP elimination by endocardial RV ablation was feasible in all 10 patients, with 53.3% successful endocardial RV radiofrequency applications for eliminating EAPs. After the procedure, VF remained inducible in 37.5% of the patients. During the 25.1 ± 29.1 months of follow-up, no patients experienced an electrical storm, and VF burden significantly decreased (median VF episodes before and after ablation: 7 and 0, respectively). EAPs are near the CA in most BrS patients, thereby requiring caution during epicardial ablation, whereas EF is less of an issue. Endocardial ablation is feasible to eliminate some EAPs and may be combined with epicardial ablation.

SIMULTANEOUS HYBRID ABLATION WITH EPI-ENDOCARDIAL MAPPING FOR THE TREATMENT OF LONG STANDING PERSISTENT ATRIAL FIBRILLATION

BACKGROUND While the paroxysmal form of atrial fibrillation (AF) can be managed pharmaceutically with antiarrhythmic drugs or by means of catheter ablation, persistent AF and longstanding persistent atrial fibrillation (LsP-AF) have presented more of a challenge. Hybrid ablation offers a minimally invasive tailored approach for these non-paroxysmal forms of AF which are associated with a more complex substrate. Moreover, given the recent evidence of endo-epicardial electrical asynchrony that can develop in patients with PAF and LsP-AF it is necessary to extensively validate lesion transmurality. Our hybrid technique employs high-density electrical mapping of both the epicardial and endocardial surfaces allowing the team to validate endpoints of ablation in an extensive manner during the procedure which mitigates the risk of incomplete ablation lines that could create re-entrant circuits and recurrence of AF (Fig.1 A-D). METHODS AND RESULTS We describe the outcomes of 15 consecutive patients who underwent simultaneous thoracoscopic hybrid ablation with epi-endocardial mapping for the treatment of LsPAF (Fig.1 E-H). Patient outcomes were recorded at 3 months, 6 months, 1 year and last follow-up greater than 1 year for each patient. Rhythm status was obtained primarily via a 24 hr Holter monitor and if that was not available, ECG measurements were used. Table 1 lists patient and procedure characteristics: age 62.7±11 yr; mean AF duration 51.6 months [range: 14-130]; previous transcatheter (TC) ablation 3/15 (20%); previous cardioversion 12/15 (80%); box lesion set 15/15 (100%); ablation time 20 ±4 mins; surgical gaps 8/15 (53%); adverse events (bleeding/stroke/pacemaker implantation) (0%). At discharge 13/15 (86.6%) of patients were in sinus rhythm (SR) with a mean post-op stay of 3.8 ± 1.1 days. SR restoration was as follows: 3 month 14/15(93.3%), 6 month 13/15 (86.7%) SR off anti-arrhythmic drugs (AAD), 1yr 11/15 (73.3%) SR off AAD. At last follow-up (22±7 month) 13/15 (86.7%) patients were in SR with 11/15 (73.3%) patients in SR off AAD; 4 patients underwent repeat TC ablation 18±3.6 month post hybrid ablation. The same areas that were endocardially targeted as surgical gaps during the index procedure were re-ablated (3/4) and areas that were not seen as surgical gaps in the first place were ablated during the repeat TC procedure (4/4). CONCLUSION Our hybrid approach is safe, feasible and has shown successful SR restoration off AAD in 73% (11/15) of our patients at 1 year follow-up and epicardial mapping before and after endocardial ablation provided an additional means of lesion validation. While the paroxysmal form of atrial fibrillation (AF) can be managed pharmaceutically with antiarrhythmic drugs or by means of catheter ablation, persistent AF and longstanding persistent atrial fibrillation (LsP-AF) have presented more of a challenge. Hybrid ablation offers a minimally invasive tailored approach for these non-paroxysmal forms of AF which are associated with a more complex substrate. Moreover, given the recent evidence of endo-epicardial electrical asynchrony that can develop in patients with PAF and LsP-AF it is necessary to extensively validate lesion transmurality. Our hybrid technique employs high-density electrical mapping of both the epicardial and endocardial surfaces allowing the team to validate endpoints of ablation in an extensive manner during the procedure which mitigates the risk of incomplete ablation lines that could create re-entrant circuits and recurrence of AF (Fig.1 A-D). We describe the outcomes of 15 consecutive patients who underwent simultaneous thoracoscopic hybrid ablation with epi-endocardial mapping for the treatment of LsPAF (Fig.1 E-H). Patient outcomes were recorded at 3 months, 6 months, 1 year and last follow-up greater than 1 year for each patient. Rhythm status was obtained primarily via a 24 hr Holter monitor and if that was not available, ECG measurements were used. Table 1 lists patient and procedure characteristics: age 62.7±11 yr; mean AF duration 51.6 months [range: 14-130]; previous transcatheter (TC) ablation 3/15 (20%); previous cardioversion 12/15 (80%); box lesion set 15/15 (100%); ablation time 20 ±4 mins; surgical gaps 8/15 (53%); adverse events (bleeding/stroke/pacemaker implantation) (0%). At discharge 13/15 (86.6%) of patients were in sinus rhythm (SR) with a mean post-op stay of 3.8 ± 1.1 days. SR restoration was as follows: 3 month 14/15(93.3%), 6 month 13/15 (86.7%) SR off anti-arrhythmic drugs (AAD), 1yr 11/15 (73.3%) SR off AAD. At last follow-up (22±7 month) 13/15 (86.7%) patients were in SR with 11/15 (73.3%) patients in SR off AAD; 4 patients underwent repeat TC ablation 18±3.6 month post hybrid ablation. The same areas that were endocardially targeted as surgical gaps during the index procedure were re-ablated (3/4) and areas that were not seen as surgical gaps in the first place were ablated during the repeat TC procedure (4/4). Our hybrid approach is safe, feasible and has shown successful SR restoration off AAD in 73% (11/15) of our patients at 1 year follow-up and epicardial mapping before and after endocardial ablation provided an additional means of lesion validation.

Recent clinical trials in atrial fibrillation.

Management of atrial fibrillation can be overwhelming with the amount of information and treatment options available today. This review discusses landmark and other clinically relevant trials published in the last 18 months. There have been several recent key clinical trials and subanalyses in the field of atrial fibrillation. Early rhythm control with ablation or antiarrhythmic medications has upended the previous practice of rate control for patients with atrial fibrillation. Vein of Marshall alcohol ablation in combination with endocardial mitral annular ablation and a hybrid epicardial/endocardial approach has shown promising results in the fight against persistent atrial fibrillation. Early ablation with cryoballoon therapy vs. antiarrhythmic therapy gives further evidence for early ablation in patients with symptomatic paroxysmal atrial fibrillation. The rapid development in technology and medications to treat atrial fibrillation, prevent stroke and improve quality of life for patients has created a vast amount of information for physicians to process. The present review will focus on the recent (within 2 years) clinical trials in atrial fibrillation and the impact they may have on your practice.

Periods of observation following combined epicardial and endocardial ablation for non‐paroxysmal atrial fibrillation: Navigating the sea of hybrid convergent procedures

De Martino et al. reported their experience with a stepwise endocardial and epicardial catheter ablation strategy for treatment of non-paroxysmal atrial fibrillation (AF) using a single-center, single-arm prospective cohort design. This article is protected by copyright. All rights reserved.

Sinus node sparing novel hybrid approach for treatment of inappropriate sinus tachycardia/postural sinus tachycardia: multicenter experience

BackgroundThe ideal treatment of inappropriate sinus tachycardia (IST) and postural orthostatic tachycardia syndrome (POTS) still needs to be defined. Medical treatments yield suboptimal results. Endocardial catheter ablation of the sinus node (SN) may risk phrenic nerve damage and open-heart surgery may be accompanied by unjustified invasive risks.MethodsWe describe our first multicenter experience of 255 consecutive patients (235 females, 25.94 ± 3.84 years) having undergone a novel SN sparing hybrid thoracoscopic ablation for drug-resistant IST (n = 204, 80%) or POTS (n = 51, 20%). As previously described, the SN was identified with 3D mapping. Surgery was performed through three 5-mm ports from the right side. A minimally invasive approach with a bipolar radiofrequency clamp was used to ablate targeted areas while sparing the SN region. The targeted areas included isolation of the superior and the inferior caval veins, and a crista terminalis line was made. All lines were interconnected.ResultsNormal sinus rhythm (SR) was restored in all patients at the end of the procedure. All patients discontinued medication during the follow-up. After a blanking period of 6 months, all patients presented stable SR. At a mean of 4.07 ± 1.8 years, normal SN reduction and chronotropic response to exercise were present. In the 51 patients initially diagnosed with POTS, no syncope occurred. During follow-up, pericarditis was the most common complication (121 patients: 47%), with complete resolution in all cases. Pneumothorax was observed in 5 patients (1.9%), only 3 (1.1%) required surgical drainage. Five patients (1.9%) required a dual-chamber pacemaker due to sinus arrest > 5 s.ConclusionsPreliminary results of this multicenter experience with a novel SN sparing hybrid ablation of IST/POTS, using surgical thoracoscopic video-assisted epicardial ablation combined with simultaneous endocardial 3D mapping may prove to be an efficient and safe therapeutic option in patients with symptomatic drug-resistant IST and POTS. Importantly, in our study, all patients had a complete resolution of the symptoms and restored normal SN activity.

Acute and chronic effects of endocardial radiofrequency ablation of septal hypertrophy in HOCM.

Endocardial radiofrequency ablation of septal hypertrophy (ERASH) is an alternative to alcohol septal ablation (ASA) or surgical myectomy for hypertrophic obstructive cardiomyopathy (HOCM). Several studies have confirmed that septal radiofrequency ablation leads to a significant reduction in the left ventricular outflow tract gradient. We aimed to report the outcomes of 41 patients who underwent ERASH with a focus on severe complications. Since 2004, 41 patients with HOCM (age: 58.2 ± 13 years) underwent ERASH at our institution. ERASH was performed, since ASA was ineffective (26 patients) or not possible (15 patients). The left ventricular outflow tract and the right ventricular septum were ablated in 26 and 15 patients, respectively. ERASH resulted in a significant reduction in acute gradient during the session and the results persisted during the 6-month follow-up (67% gradient reduction at rest and 73% after provocation, p = .0002). Pacemaker dependency after ERASH was 29% and pericardial tamponade occurred in two patients. In four patients, ERASH induced a paradoxical increase in obstruction (PIO), beginning suddenly at 30 min after the procedure and leading to lethal shock in one patient. PIO was not observed after ERASH from the right ventricular aspect. Morbidity and mortality after ERASH were higher than those after ASA. PIO, a life-threatening complication, was observed in 9% of the patients. Our data indicate that ERASH might be considered in patients who are not candidates for surgical myectomy or ASA.

Diagnosis, significance, and management of ventricular thrombi in patients referred for VT ablation.

In patients with structural heart disease presenting with ventricular tachycardia (VT), detection of ventricular thrombi and subsequent management can be challenging. This study aimed to assess the value of multimodality imaging with cardiac magnetic resonance imaging (CMR), contrast-enhanced transthoracic echocardiography (TTE), and computed tomography (CT) for thrombus detection as well as a management algorithm geared towards anticoagulation and deferred ablation for patients referred for VT ablation. A total of 154 consecutive patients referred for VT ablation underwent preprocedural multimodality imaging with CMR, CT, and TTE. In 9 patients (6%) a new ventricular thrombus was detected and anticoagulation was initiated. Thrombi were detected by CMR in nine patients, by CT in seven patients, and by TTE in two patients. Five patients eventually underwent endocardial VT ablation procedures 6.0 ± 2.0 months after initiation of anticoagulation with one patient also requiring an epicardial approach. Two patients died while on anticoagulation, unrelated to ventricular arrhythmia. Four of five patients were rendered non-inducible and no testing was performed in 1/5 patients. Areas containing left ventricular thrombi were non-excitable with pacing. Six of thirty-two inducible VTs were mapped in close vicinity of ventricular thrombi. No clinical embolic events occurred during the ablation procedures. Ventricular thrombus was detected in 6% of consecutive patients with structural heart disease undergoing VT ablation. CMR was the most sensitive modality, while contrast-enhanced TTE failed to detect the majority of thrombi. Anticoagulation followed by ablation can be safely and successfully performed in patients with ventricular thrombi.

B-PO02-115 MINIMALIST APPROACH TO HYBRID ABLATION FOR ATRIAL FIBRILLATION: FEASIBILITY & EFFICACY OF UNILATERAL EPICARDIAL ACCESS

Hybrid ablation surgery for atrial fibrillation (AF) has evolved from bilateral to unilateral left-sided only video-assisted thoracoscopic surgical techniques. However, an optimal strategy for hybrid AF ablation that optimizes patient wellbeing and hospital expenditures remains undetermined. To evaluate the feasibility and efficacy of hybrid ablation surgery for treatment of AF, and perform the first evaluation of unilateral left-sided versus bilateral epicardial access. Patients with documented AF who underwent hybrid ablation consisting of thoracoscopic epicardial ablation with percutaneous catheter based endocardial ablation for treatment of atrial fibrillation were followed post-operatively for major events. Major events were classified into two categories consisting of 1) feasibility, comprising all-cause mortality and major morbidities, and 2) efficacy, which included recurrence of atrial arrhythmia, cessation of antiarrhythmic drugs (AAD), and completeness of lesion set. A total of 84 consecutive patients were consented for hybrid ablation. Patients presented with an average AF duration of 85.9 months before hybrid ablation. 80 patients underwent successful thoracoscopic epicardial ablation, and 63 patients completed both epicardial and endocardial hybrid ablation. Complete conduction block was achieved in 89% (56/63) of patients after thoracoscopic endocardial ablation. At one-year, 87% (48/55) of patients were free from AF and 75% (41/55) were free from AF and off AAD. Unilateral epicardial ablation was associated with significantly shorter hospital length of stay compared to bilateral surgical approached (3.9 vs. 7.4 days, p = 0.003) with no difference in freedom from AF between groups at 1 year. Combined hybrid thoracoscopic and endovascular ablation for atrial fibrillation is effective for patients at high risk for recurrence after catheter ablation. The unilateral surgical approach is associated with a significantly shorter hospital stay with no appreciable effect on procedure success rates.

B-PO01-068 LONG-TERM OUTCOME OF ENDOCARDIAL-ONLY VERSUS COMBINED ENDOCARDIAL-EPICARDIAL HOMOGENIZATION OF THE SCAR FOR TREATMENT OF VENTRICULAR TACHYCARDIA IN PATIENTS WITH ISCHEMIC CARDIOMYOPATHY

NA We investigated the ablation success of scar homogenization with combined (epicardial + endocardial) versus endocardial-only approach for ventricular tachycardia (VT) in patients with ischemic cardiomyopathy (ICM) at 5 years of follow-up. Consecutive ICM patients undergoing VT ablation at our center were classified into group 1: endocardial scar homogenization and group 2: endocardial +epicardial scar homogenization. Patients with previous open heart surgery were excluded. All patients underwent bipolar substrate mapping with standard scar settings defined as normal tissue >1.5 mV and severe scar <0.5 mV. Non-inducibility of monomorphic VT was the procedural endpoint in both groups. Patients were followed up twice a year for 5 years with implantable device interrogations. A total of 361 (Group 1: 291 and group 2: 70) patients were included in the study (mean age: 67 years, male: 88.4%). At 5 years, significantly higher number of patients from group 2 remained arrhythmia-free (figure 1). Of those patients, 87 (45%) and 51 (89%) from group 1 and 2 respectively were off-anti-arrhythmic drugs (AAD) (p<0.001). After adjusting for age, gender, hypertension, diabetes, and obstructive sleep apnea, scar homogenization using endo-epicardial approach was associated with 51% less recurrence compared to the endocardial ablation strategy (Hazard Ratio : 0.49, 95% CI : 0.27-0.89, p : 0.02). In this series of patients with ischemic cardiomyopathy and VT, endo-epicardial scar homogenization was associated with a lower need for AAD and a significantly lower recurrence rate at 5-years of follow-up compared to the endocardial ablation alone.

Surgical ablation supplemented by ethanol injection for ventricular tachycardia refractory to percutaneous ablation.

A combination of endocardial and epicardial approaches has improved the overall success rate of ventricular tachycardia (VT) ablation in patients with cardiomyopathy. However, the origins of some VTs are truly intramural or close to coronary arteries, which makes this combined strategy either prone to failure or too risky. This observational study aimed to explore the feasibility and efficacy of direct epicardial ablation combined with intramural ethanol injection via surgical approach for inaccessible intramural VTs or VTs too close to coronary arteries. In four canines ventricular lesions produced by direct epicardial injection of ethanol were assessed. Six consecutive patients with recurrent VT refractory to catheter endocardial and epicardial RF ablation and that remained inducible after surgical epicardial mapping and RF ablation were included. Ethanol was injected by needle at the epicardial RF ablation sites. The primary outcome was freedom of sustained VT determined by device interrogation and periodical 24-h holter recordings subsequently. In an animal study, the lesions were homogenous and increased in size with the volume of ethanol injected. In all six patients, ethanol injection at the target sites in the anterior or lateral left ventricle abolished inducible VT. Over a median follow-up of 22 months (range, 6-65), all patients remained free of sustained VT. One patient died of pulmonary infection one year after the procedure. A hybrid strategy of surgical ablation combined with intramural ethanol injection is feasible and effective in patients with multiple failed percutaneous ablation attempts.