Refractory AF Research Articles

Abstract 12028: Neural Mechanisms of Postoperative Atrial Fibrillation Suppression Using Nanoformulated Calcium Targeting Cardiac Ganglionated Plexi

Introduction: The neural mechanisms of postoperative atrial fibrillation (POAF) remain unclear. Hypothesis: We hypothesize that injection of left atrial GP with nanoformulated calcium chloride (nCaCl2) causes GP neuroapoptosis, inhibition of sympathetic and vagal nerve activity (SNA, VNA) and consequent suppression of POAF. Methods: In a novel canine model of POAF with serial bilateral thoracotomy surgeries, we assessed ambulatory SNA and VNA before (baseline), 3-days after and 6-weeks after injection of 1ml of nCaCl2 (n=6) or sham (n=3) into each of 4 left atrial GP. We also serially assessed atrial effective refractory period (AERP) and AF vulnerability (AFV) by in-vivo programmed stimulation before and 6 weeks after nCaCl2 treatment. Results: In this POAF model, postoperative atrial electrical remodeling manifests as a reduction in AERP and increase in AFV from baseline (week 0) to postop (week 3) (Table). Subsequent nCaCl2 treatment at week 3 reversed these changes (increased AERP, decreased AFV) at 6 weeks post-treatment, vs persistently decreased AERP and increased AFV in the sham control group. Three days after nCaCl2 treatment, there was a reduction in SNA and VNA vs baseline and increase in mean and standard deviation (SD) RR intervals vs baseline, whereas the sham group demonstrated the opposite changes (increased SNA, decreased mean RR and SDRR vs baseline). At 6-weeks post-treatment, mean and SDRR remained persistently increased whereas SNA remained suppressed vs baseline. In contrast, SNA remained elevated and mean RR decreased vs baseline in the sham group. Histology demonstrated neuronal apoptosis within GP without atrial myocardial infiltration in nCaCl2-treated but not in sham. Conclusions: Modulation of cardiac GP with nanoformulated calcium causes GP neuroapoptosis, which exerts a persistent sympatho- and parasympatholysis across the cardiac neuraxis, promoting reversed atrial electrical remodeling and durable suppression of POAF.

Biventricular versus Conduction System Pacing after Atrioventricular Node Ablation in Heart Failure Patients with Atrial Fibrillation.

Conduction system pacing (CSP) modalities, including His-bundle pacing (HBP) and left bundle branch pacing (LBBP), are increasingly used as alternatives to biventricular (BiV) pacing in heart failure (HF) patients scheduled for pace and ablate strategy. The aim of the study was to compare clinical outcomes of HF patients with refractory AF who received either BiV pacing or CSP in conjunction with atrio-ventricular node ablation (AVNA). Fifty consecutive patients (male 48%, age 70 years (IQR 9), left ventricular ejection fraction (LVEF) 39% (IQR 12)) were retrospectively analysed. Thirteen patients (26%) received BiV pacing, 27 patients (54%) HBP and 10 patients (20%) LBBP. All groups had similar baseline characteristics and acute success rate. While New York Heart. Association (NYHA) class improved in both HBP (p < 0.001) and LBBP (p = 0.008), it did not improve in BiV group (p = 0.096). At follow-up, LVEF increased in HBP (form 39% (IQR 15) to 49% (IQR 16), p < 0.001) and LBBP (from 28% (IQR 13) to 40% (IQR 13), p = 0.041), but did not change in BiV group (p = 0.916). Conduction system pacing modalities showed superior symptomatic and echocardiographic improvement compared to BiV pacing after AVNA. With more stable pacing parameters, LBBP could present a more feasible pacing option compared to HBP.

Conduction system pacing +/- CRT post AV nodal ablation for drug refractory AF - Feasibility, safety and medium term outcomes

Conduction system pacing +/- CRT post AV nodal ablation for drug refractory AF - Feasibility, safety and medium term outcomes

INTERMEDIATE TERM PERFORMANCE AND SAFETY OF LEFT BUNDLE BRANCH AREA CONDUCTION SYSTEM PACING LEADS: A MULTICENTER PROSPECTIVE STUDY

<h3>BACKGROUND</h3> Left bundle branch area pacing (LBBAP) has shown to be a reliable alternative to His bundle pacing (HBP) for physiologic pacing. There are limited data on the intermediate term performance of LBBA pacing leads. Objective: To evaluate the intermediate term performance and safety of LBBAP. <h3>METHODS AND RESULTS</h3> Patients referred for pacemaker implantation at two academic centers between 02/2019 - 1/2021 were considered for LBBAP. LBBAP was performed by implanting the 3830 lumenless lead using the C315 fixed curve or C304 His deflectable sheath (Medtronic, MN). Implant success rates, complications and electrophysiological parameters were assessed. LBBAP was successful in 566/619 patients (91%). Mean age was 73±12 yrs, 46% were women. 37% had QRSd >130 ms, 25% RBBB, 11% LBBB, 4% IVCD. Pacing indications include sinus node dysfunction in 27%, AV block 56%, CRT 7% and refractory AF 10%. Mean procedural duration was 73±32 mins (median 70 mins) and fluoroscopic time was 10±7 mins (median 8 mins). Baseline QRSd was 119±31ms vs paced QRSd was 113±12ms (p < 0.001). Mean LV activation time was 73±12ms at high output and 76±12ms at low output. LBB potentials were noted in 175 (31%) patients. Transition from non-selective to selective LBBA or septal pacing was noted in 393 (74%). Pacing threshold and R waves were 0.74±0.3V@0.4ms and 11±5mV at implant and 0.83±0.2V@0.4ms and 15± 5mV at a mean follow-up of 167±172 days (range 25-662 days) (Fig). The only complication was LBBAP lead dislodgement in 6 (1%) patients occurring within 24-72 hours. <h3>CONCLUSION</h3> LBBA pacing is safe and feasible with high success rates and low complication rates during intermediate term follow-up.

B-AB14-02 INTERMEDIATE TERM PERFORMANCE AND SAFETY OF LEFT BUNDLE BRANCH AREA CONDUCTION SYSTEM PACING LEADS: A MULTICENTER PROSPECTIVE STUDY

Left bundle branch area pacing (LBBAP) has shown to be a reliable alternative to His bundle pacing (HBP) for physiologic pacing. There are limited data on the intermediate term performance of LBBAP leads. To evaluate the intermediate term performance and safety of LBBAP. Patients referred for pacemaker implantation at two academic centers between 02/2019 - 1/2021 were considered for LBBAP. LBBAP was performed by implanting the 3830 lumenless lead using the C315 fixed curve or C304 His deflectable sheath (Medtronic, MN). Implant success rates, complications and electrophysiological parameters were assessed. LBBAP was successful in 566/619 patients (91%). Mean age was 73±12 yrs, 46% were women. 37% had QRSd >130 ms, 25% RBBB, 11% LBBB, 4% IVCD. Pacing indications include sinus node dysfunction in 27%, AV block 56%, CRT 7% and refractory AF 10%. Mean procedural duration was 73±32 mins (median 70 mins) and fluoroscopic time was 10±7 mins (median 8 mins). Baseline QRSd was 119±31ms vs paced QRSd was 113±12ms (p<0.001). Mean LV activation time was 73±12ms at high output and 76±12ms at low output. LBB potentials were noted in 175 (31%) patients. Transition from non-selective to selective LBBA or septal pacing was noted in 393 (74%). Pacing threshold and R waves were 0.74±[email protected] and 11±5mV at implant and 0.83±[email protected] and 15± 5mV at a mean follow-up of 167±172 days (range 25-662 days) (Fig). The only complication was LBBAP lead dislodgement in 6 (1%) patients occurring within 24-72 hours. LBBA pacing is safe and feasible with high success rates and low complication rates during intermediate term follow-up.

B-PO03-086 AV JUNCTION ABLATION IN PATIENTS WITH CONDUCTION SYSTEM PACING LEADS: A COMPARISON OF HIS BUNDLE VS LEFT BUNDLE BRANCH AREA PACING LEADS

Conduction system pacing (CSP) (His bundle pacing-HBP or left bundle branch area pacing-LBBAP) provides physiologic pacing in patients with drug/ablation refractory AF undergoing atrioventricular junction (AVJ) ablation. To compare the lead and procedural characteristics in patients with CSP leads undergoing AVJ ablation. Consecutive patients with CSP leads referred for AVJ ablation at a single center between 01/2015-01/2021 were included. Pre- and post-ablation lead and procedural characteristics were assessed. 95 AVJ ablation procedures were performed in 89 patients with CSP leads: 49 HBP, 40 LBBAP. There was no significant difference in demographics except for more women in LBBAP vs HBP (77% vs 39%, p=<0.001). AVJ was successful in 87% (7 failed) patients with HBP vs 100% (p=0.03) with LBBAP. The mean procedure time (min) (44±24 vs 33±16, p=0.02) and fluoroscopic time (min) (16±18 vs 7±6, p=0.002) was significantly higher in HBP vs LBBAP. RF time to block (min) was (3.3±4.5 vs 2.3±3.3, p=0.22) and total RF time (min) was (4.9±4.6 vs 3.7±3.4, p=0.18) in HBP vs LBBAP respectively. There were 3 (5%) complications in the HBP group, all related to retrograde ablation at left His after failed right sided ablation (1 acute increase in pacing thresholds >1V and 2 exit block) and 2 of these required lead revisions. No complications were seen in the LBBAP group. There was no difference in the pre- and post-ablation paced QRSd between the groups. AVJ ablation in the presence of a HBP lead can be very challenging. The presence of a LBBA lead allows for a shorter procedural and fluoroscopic time along with a lower complication and higher success rates.

Abstract 15344: Outcomes of the Hybrid Convergent Procedure Compared to Catheter Ablation Stratified by Anti-arrhythmic Drug Usage: Results From Converge Ide, Prospective, Randomized, Multi-center Trial

Introduction: Atrial fibrillation increases the risk of stroke 5-fold. The efficacy of endocardial catheter ablation (CA) for drug - refractory persistent and longstanding persistent AF (PsAF) is limited and has led to the development of minimally invasive hybrid epicardial/endocardial ablation technique (hybrid Convergent) to achieve a comprehensive lesion set with durable transmural lesions. The CONVERGE IDE randomized controlled trial prospectively evaluated the effectiveness of Convergent ablation compared to CA for the treatment of PsAF. Methods: PsAF patients, &gt;18 to &lt;80 years with left atrial sizes up to 6 cm, no limit on the duration of PsAF, refractory/intolerant to class I/III anti-arrhythmic drugs (AADs) were randomized 2:1 to Convergent vs CA at 27 sites (US, UK). Freedom from atrial arrhythmia (AF/AFL/AT) through 12-mo was assessed using 24-hr Holter at 6-mo and 12-mo and ECGs at 3-mo or unscheduled visits. An analysis of freedom from atrial arrhythmia stratified by AAD use was performed. Results: One hundred fifty-three patients (102 Convergent, 51 CA) with similar baseline characteristics were treated. Body mass index (mean 33.7, range 19.1- 50.1) and years since PsAF diagnosis (mean 4.4 years, range 0.5 - 26.0 years) were high; 42.5% (65/153) patients had longstanding persistent AF. In the Convergent arm, 4 major adverse events (3.9%, 4/102) were reported through the first 7 days and additional 4 events (3.9%) from days 8 - 30. The safety rates were lower than the performance goal of 12%. Rates of freedom from atrial arrythmia stratified by AAD use are included in Table1. Irrespective of the criteria, the hybrid Convergent procedure demonstrated significantly higher treatment success compared to CA (RR 1.28 - 1.67, p&lt;0.05). Conclusion: The hybrid Convergent procedure combining epicardial and endocardial ablation is safe and has superior effectiveness as compared to the endocardial catheter ablation for the treatment of PsAF, irrespective of AAD use.

Ablation of Atrial Fibrillation in Patients with Congenital Heart Disease.

With improved surgical techniques and medical management for patients with congenital heart diseases, more patients are living longer and well into adulthood. This improved survival comes with a price of increased morbidity, mainly secondary to increased risk of tachyarrhythmias. One of the major arrhythmias commonly encountered in this subset of cardiac patients is AF. Similar to the general population, the risk of AF increases with advancing age, and is mainly secondary to the abnormal anatomy, abnormal pressure and volume parameters in the hearts of these patients and to the increased scarring and inflammation seen in the left atrium following multiple surgical procedures. Catheter ablation for AF has been shown to be a very effective treatment modality in patients with refractory AF. However, data and guidelines regarding catheter ablation in patients with congenital heart disease are not well established. This review will shed light on the procedural techniques, success rates and complications of AF catheter ablation in patients with different types of CHD, including atrial septal defects, tetralogy of Fallot, persistent left superior vena cava, heterotaxy syndrome and atrial isomerism, and Ebstein anomaly.

Predictors of long fluoroscopy time during ablation of atrial fibrillation

Introduction Catheter ablation has emerged as effective therapy for AF. Ablation of AF is often a complex and long procedure requiring long fluoroscopy time. An important complication of AF ablation is the delayed effect of the radiation received by the patients and operator. Objective We conducted this prospective observational cohort to study factors associated with long fluoroscopy time during catheter ablation of AF. Patients and Method This is a prospective observational cohort study, conducted between January 2013 and January 2014 in Critical Care Medicine Department – Cairo University. Patients with symptomatic, drug refractory AF were enrolled. All patients underwent pulmonary vein isolation ± left atrial ablation according to AF type. All operators performed at least 50 previous AF ablation procedures. Clinical (AF type and LA geometry and diameter), and technical (Mapping system and catheters) variables were recorded for each patient. The primary endpoint was to identify variables associated with long fluoroscopy time. Secondary endpoints included identification of complications. Results Thirty-one patients with paroxysmal (n=25) and persistent (n=6) AF were enrolled. Pulmonary vein isolation was achieved in all patients. Average fluoroscopy time was 54.2 ± 31.7 mins. We found that the use of CARTO3® system was associated with significantly shorter fluoroscopy time compared to NavX EnSite Velocity® system (48 ± 29.8 vs. 78 ± 27.9 mins, P = 0.02). Using 20-pole circular mapping catheter was also associated with shorter fluoroscopy time as opposed to 10-pole one (47.6 ± 23.2 vs. 98.8 ± 48.4 mins, P = 0.03). Only two patients (6.4%) suffered major complications; major groin bleeding and pericardial tamponade. Conclusion The use of CARTO3® navigation system and 20-pole circular mapping catheter seems seems to be associated with shorter fluoroscopy time than EnSite Velocity® navigation system and 10-pole circular mapping catheter.

Cryoablation for the Treatment of Drug Refractory Symptomatic Atrial Fibrillation: A Regional Medical Center Experience.

PVI is an effective, guideline-based treatment for drug refractory symptomatic AF. Balloon cryoablation has been shown to be a safe and effective method for PVI. In the STOP-AF trial, data was produced from practitioners performing PVI with significant experience at high volume centers. This study evaluates the effectiveness and safety of treating symptomatic, drug refractory AF with PVI via cryoablation after implementation in a regional medical center. This represents a retrospective analysis of outcomes after cryoablation treatment for AF in 71 patients over 354.7 +/- 164.4 days. Reported and recorded episodes of AF were categorized into a representative percent of AF "burden" for each 90 day period. Primary effectiveness and safety end points paralleled those of the STOP-AF trial. Patients undergoing cryoablation had a 91% reduction of AF burden at 6 months following the procedure with an event-free survival rate of 45.5 % at a mean follow up of 12 months. The mean burden reduction was 3.21% per quarter. Anti-arrhythmic and anticoagulant medication use was reduced by 14.3% and 26.8% respectively. Significant complications included one report of pulmonary vein stenosis, one report of pseudoaneurysm and 5.5% of patients had transient pericarditis or pericardial effusion following the procedure. The results of this study were comparable to those of the high volume multi-center STOP-AF trial. PVI via cryoablation is a safe and effective alternative treatment of drug refractory symptomatic AF in the setting of a regional medical center.

Pulmonary vein isolation and renal sympathetic denervation in CKD patients with refractory AF

Pulmonary vein isolation and renal sympathetic denervation in CKD patients with refractory AF

Left atrial appendage closure device implantation and pulmonary vein isolation as a comprehensive treatment for atrial fibrillation

Objective. This randomized clinical trial was designed to assess the impact of pulmonary vein isolation (PVI) combined with LAA occlusion on patients with high-risk AF. Methods. Patients with a history of symptomatic paroxysmal (P) AF and/or persistent (Pers) AF and CHA2DS2-VASc score ≥2 and HAS-BLED score ≥3 were randomized in groups with PVI only (n = 44) and PVI combined with LAA occlusion (n = 45). All patients were followed during 24 months in order to evaluate the safety of thromboembolic complications and to monitor the heart rhythm conducted by means of an implantable cardiac monitor. Results. 6 patients from the PVI with LAA occlusion group were transferred to the PVI only group because of a failure to implant a LAA closure device. Based on ILR data, by the end of the follow-up 33 (66%) out of 50 patients in the PVI only group and 23 (59%) out of 39 patients in the PVI with LAA closure device implantation group were free from atrial fibrillation and flutter without antiarrhythmic drugs (p = 0.34). In the blanking period, AF% was significantly higher in the PVI with LAA closure group than that in the PVI-only group, 9.7±10.8 and 4.2±4.1% respectively (p = 0.004). After the blanking period, the AF% was similar in both groups. During the entire follow-up, no AF/intervention-related complications were observed. Conclusion. The combination of LAA closure device implantation with PVI seems to be a safe procedure. However, it does not improve the efficacy of PVI in patients with symptomatic refractory AF. But in the blanking period LAA occlusion increases AF %.

Impact of Tricuspid Regurgitation on the Success of Atrioventricular Node Ablation for Rate Control in Patients With Atrial Fibrillation: The Node Blast Study

Atrioventricular node (AVN) ablation is an effective treatment for symptomatic patients with atrial arrhythmias who are refractory to rhythm and rate control strategies where optimal ventricular rate control is desired. There are limited data on the predictors of failure of AVN ablation. Our objective was to identify the predictors of failure of AVN ablation. This is an observational single-center study of consecutive patients who underwent AVN ablation in a large academic center. Baseline characteristics, procedural variables, and outcomes of AVN ablation were collected. AVN "ablation failure" was defined as resumption of AVN conduction resulting in recurrence of either rapid ventricular response or suboptimal biventricular pacing. A total of 247 patients drug refractory AF who underwent AVN ablation at our center with a mean age of 71 ± 12 years with 46% being males were included. Ablation failure was seen in 11 (4.5%) patients. There were no statistical differences between patients with "ablation failure" versus "ablation success" in any of the baseline clinical variables. Patients with moderate-to-severe tricuspid regurgitation (TR) were much more likely to have ablation failure than those with ablation success (8 [73%] vs 65 [27%]; p = 0.003). All 11 patients with ablation failure had a successful redo procedure, 9 with right and 2 with the left sided approach. On multivariate analysis, presence of moderate-to-severe TR was found to be the only predictor of failure of AVN ablation (odds ratio 9.1, confidence interval 1.99 to 42.22, p = 0.004). In conclusion, moderate-to-severe TR is a strong and independent predictor of failure of AVN ablation.

Cryoballoon ablation of atrial fibrillation: How important is the proper selection of patients?

Relation between pre-procedural selection of patients and the success rate after a single cryoballoon ablation (CAB) procedure is unknown. CAB was performed in 378 (65% male, median age 58 years, 85% paroxysmal atrial fibrillation [AF]) consecutive patients with symptomatic and drug refractory AF. The combined ALARMEc (Atrial fibrillation type, Left Atrium size, Renal insufficiency, Metabolic syndrome, cardiomyopathy) risk score was calculated for each individual patient. The end-point of the study was the first AF, atrial flutter or atrial tachycardia recurrence after the 3-month blanking period in the 1-year follow-up since the index procedure, in the absence of anti-arrhythmic (class I and III) therapy. Single and multi-catheter approach was used in 79% and 21% of patients, respectively. The acute success rate with single and multi-catheter approach was 79% and 99%, respectively. The overall 1-year success rate after a single CAB procedure was 70%. The 1-year outcome was: 83%, 70%, 60%, 40% and 29% in patients with ALARMEc risk score: 0, 1, 2, 3 and 5, respectively. Total rate of complications was 11%, including transient phrenic nerve palsy in 9.5% of cases. Multi-catheter approach was needed in 21% of patients to achieve acute pulmonary vein isolation. Patients with low (≤ 1) ALARMEc risk score, preferably young individuals with sole paroxysmal AF (ALARMEc = 0), are best candidates for CBA procedure. Performing CBA in patients with higher (> 2) ALARMEc risk score should be avoided. Phrenic nerve palsy was a transient complication.

Pulmonary vein isolation for atrial fibrillation in the postpneumonectomy population: a feasibility, safety, and outcomes study.

Pulmonary vein isolation (PVI) of the remnant pulmonary vein (PV) stumps in pneumonectomy patients has not been well characterized. This is a multicenter observational study of patients with a remnant PV stump after pneumonectomy. Consecutive patients with a history of pneumonectomy and who had undergone RF ablation for drug refractory AF were identified from the AF database at the participating institutions. There were 15 patients in whom pneumonectomy was performed, for resection of tumors in 10, infection in 4, and bullae in 1 patient and who underwent RF ablation for AF. The mean age was 63 ± 7 years. The stumps were from the right lower PV in 5, left upper PV in 5, left lower PV in 3, and right upper PV in 2 patients. All the PV stumps were electrically active with PV potentials and 9 (60%) of them had triggered activity. PVI was performed in 14 and focal isolation in 1 patient. At 1-year follow-up, 80% were free of AF, off of antiarrhythmic medications. PV stumps in AF patients with previous pneumonectomy are electrically active and are frequently the sites of active firing. Isolation of these PV stumps can be accomplished safely and effectively using catheter ablation with no practical concern for PV stenosis or compromising PV stump integrity.

Abstract 13259: Electrophysiologic Mapping Identifies Stable Organized Tachyarrhythmias ("Rotors") in Both Atria during Spontaneous Atrial Fibrillation with Systolic Heart Failure

Introduction: Stable organized atrial tachyarrhythmias (ATs) /"rotors" that maintain AF have been identified in patients (pts) with paroxysmal atrial fibrillation (PAF) &amp; persistent AF (PRAF) with no or minimal heart disease. Hypothesis: Biatrial ATs occur in AF pts with systolic heart failure (HF). Methods: We performed simultaneous contact catheter mapping of the RA &amp; LA using 3 D non-contact mapping ) in 83 refractory AF pts during spontaneous AF episodes.Spontaneous atrial premature beats (APBs) &amp; triggered ATs were analyzed. We also compared regional distribution of ATs &amp; activation patterns in pts with &amp; without HF. Results: 24 HF pts, mean age of 62±9 years, 75% male with mean left ventricular ejection fraction (LVEF) 45.5±9% and mean left atrial (LA) size 4.35±0.8 cm were mapped. They had 42 APBs that triggered 26 distinct organized stable ATs/"rotors". Each pt had 1 to 4 RA or LA regions showing triggering APBs (mean 1.75/pt) initiating AT. APBs arose predominantly from the RA or LA septum (45%) &amp; superior LA/PV (24%) regions (Fig 1a). A biatrial distribution of the stable ATs/"rotors" occcurred in HF pts (Fig 1b) with few focal ATs. Compared to pts without HF (n=59), HF pts (n=24) trended to have more PRAF (83% vs 66%, p=0.18). 78 organized stable ATs/"rotors" were compared for regional distribution in PRAF pts with HF (n=16) &amp; without HF (n=32). Stable ATs with focal LA/PV origin were uncommon in both groups (7% vs. 15%). LA ATs/"rotors" were similar (26% vs. 17%; p=0.58) as were typical RA flutter and atypical RA ATs/"rotors" in both groups (Fig 1c). Conclusions: 1. A majority of APBs initiating AF in HF pts originated from the septal and superior LA/PV regions. 2. While triggers are still frequently present with the LA/PV origin in HF pts, stable ATs/"rotors" had biatrial distribution &amp; a lesser frequency of focal LA/PV ATs. 3. This spectrum of ATs/"rotors" was similar to PRAF pts without HF, potentially supporting similar ablative interventions in both pt groups.

Comparison of end-diastolic versus end-systolic cardiac-computed tomography reconstruction interval in patient's prior to pulmonary vein isolation.

PurposeAim of the study was to investigate diagnostic accuracy of cardiac computed tomography angiography (CCTA) between left ventricular end-systolic (LVES) and left ventricular end-diastolic (LVED) cardiac phase for thrombus detection in patient’s prior to pulmonary vein isolation (PVI).Materials and methods182 consecutive Patients with drug refractory AF scheduled for PVI (62.6% male, mean age 64.1 ± 10.2 years) underwent routine pre-procedural evaluation including transesophageal echocardiography (TEE) and CCTA for evaluation of left atrial (LA)/left atrial appendage (LAA) anatomy and thrombus formation. Qualitative and quantitative analysis (using aorta ascendens (AA)/LAA ratio) was performed. Measurements of the LA/LAA in LVES and LVED cardiac phase were obtained.ResultsEnd-systolic volumes (LA/LAA) measured in 30 patients without filling defects as control group and all 14 with filling defects of 182 patients were significantly larger (p < 0.01) than in end-diastolic phase. Qualitative analysis was inferior to quantitative analysis using LA/LAA ratio (<0.5; accuracy: 100%, 88%,100%, 99% vs 100%). 5 out of 182 patients (2.7%) showed thrombus formation of the LAA in CCTA confirmed by TEE and quantitative analysis. Intra/-interobserver variability was lower in end-systolic vs end-diastolic reconstruction interval.ConclusionFor evaluating CCTA datasets in patients prior PVI, the LVES reconstruction interval is recommended due to significantly larger LA/LAA volumes and lower intra/- interobserver variability’s.

Robotic ablation of paroxysmal atrial fibrillation saves time and irradiation dose

We studied 150 patients (pts) (86 males and 64 females) having a mean age of 51.3 yrs (54 > 50, 96 below 50 yrs), who suffered from symptomatic drug refractory paroxysmal AF. Cardiac MSCT image integration to the 3D electroanatomic LA map was used in 106 pts (70.6%, however all of them underwent intracardiac echo guided imaging during the ablation procedure. 40 pts underwent manual RF ablation using CARTO, 40 pts underwent ablation using NavX system, 70 pts underwent robotic ablation using Sensui system. Pulmonary vein isolation was done to all pts using either pulmonary vein (PV) antral isolation in 116 (77.3%) or circumferential pulmonary vein ablation in 34 pts (22.7%). Circumferential PV ablation was usually associated with posterior wall ablation. All pts were followed at 3, 6, 9, and 12 months. 34 Patients (22.6%) developed early recurrence of AF after an initial blanking period of 3 months. We had 16 patients(10.6%) with treatment failure at short term follow up, this number increased to 18 patients (12%) at midterm follow up and further small increase to 20 patients (13.3%) at long term follow up, recurrences were any episode of AF and/or AFL/AT > 30 s after the blanking period. The incidence of recurrence of AF in males was 13% (11/86), 14% in females (9/64), P NS.Comparison between manual and robotic groups as regards ablation points. Groups no. of patients Mean P Total no. of ablation points Manual group 80 72.2 0.000 ∗ Robotic group 70 49.9 Total ablation time Manual group 80 2094.8 0.000 ∗ Robotic group 70 1323.1 Total fluoroscopy time Manual group 80 19.9 0.000 ∗ Robotic group 70 6.9 Total fluoroscopy dose Manual group 80 2257 0.000 ∗ Robotic group 70 552.7 None in 92.5%, air embolism zero, cardiac tamponade zero, trivial pericardial effusion 1, groin hematoma 5%, pulmonary vein stenosis >50% zero. No difference in complications between robotic and manual groups. Robotic ablation of paroxysmal atrial fibrillation saves time and irradiation dose.

Abstract 9121: Does AF Burden Measured By Implantable Loop Recorder During Post-ablation Blanking Period Predict Response At 12 Month Follow-up?

Introduction: The aim of this study was to identify if there is a threshold of AF burden during the first months post-ablation obtained through continuous subcutaneous monitoring that can identify patients at risk of subsequent AF recurrences. Methods: 613 patients with symptomatic drug refractory AF (17% with persistent AF) were enrolled in this retrospective analysis. All patients underwent circumferential pulmunary vein isolation (PVI) and were implanted with an ILR for collecting data on AF burden during 12-month follow-up. AF freedom (Responders) was defined as AF%&lt;0.5% during follow-up period. A ROC curve analysis was performed to identify the value of AF burden during the first 2 months post ablation (Blanking Period, BP) that was predictive of late recurrence of AF. Results: After the first ablation procedure, 396 (65%) of the 613 patients were AF-free at 12-month: 346 out of 508 (68%) in the paroxysmal AF group and 50 out of 105 (47%) in the persistent AF group. Using the ROC curve (Fig 1), the specificity corresponding to 90% sensitivity was 75%. The corresponding threshold in the AF burden during the blanking period able to identify patients at risk of late recurrences was 7.1%, corresponding to 102h (= 4.25 days) in AF during the 2 months BP. At the multivariate analysis, a threshold in the AF burden &lt;7.1% during BP was still highly significant (p&lt;0.0001) and the odds of responders/non-responders was 21.5 (10.8 - 42.9). Conclusions: The BP AF pattern predicted response to catheter ablation. An AF burden ≥7.1% assessed by continuous monitoring was a powerful predictor of subsequent AF recurrence after initial ablation, and thus be an appropriate guide for early re-intervention.

Pulmonary Vein Isolation Plus Roof Line for Patients with Persistent AF

Background: Pulmonary vein antral isolation (PVAI) is highly successful in paroxysmal AF but less effective in persistent AF of increasing duration. The “step wise” approach requires long procedural and ablation times, considerable expertise and may not be required in all persistent AF patients. We present a single operator experience in patients with persistent AF of mean two years undergoing PVAI with LA roof line. Methods: Fifty patients (mean 61.4 ± 8.8 years, LA size 28.5 ± 5.3 cm2, mean duration of continuous AF 11 ± 10.3 months) with persistent drug refractory AF underwent PVAI between 1/8/2006 and 1/3/2011. Hypertension was present in 28% and systolic heart failure in 16%. Minimum of 12-month follow-up included clinical review, ECG and six-monthly holter-monitoring. Results: PVAI using an irrigated-tip catheter and guided by a 3D mapping system was completed in 100% with a LA roof line with conduction block (72%). AF was present in 76% at procedure commencement with reversion to SR in 16% and DCR in 60%. Twelve month single procedure success was 58%. Second procedures were performed in 40% after a mean of 12 ± 10.8 months. PV reconnection occurred in 90% (>2 veins in 70%). PV re-isolation was performed in all patients with additional linear ablation in patients with minimal reconnection. At mean follow up of 28 ± 13 months, 78% were in SR (40% off anti-arrhythmic medications) Conclusion: PVAI and an LA roof line is an effective strategy in selected patients with persistent AF. Extensive atrial ablation to sinus rhythm may not be required in all patients with persistent AF.