Incidence and pattern of conduction gaps after pulmonary vein isolation with the endoscopic ablation system.

PURPOSE: Durable pulmonary vein isolation (PVI) is the goal of atrial fibrillation (AF) ablation. The endoscopic ablation system (EAS) is associated with a high rate of persistent PVI. The aim of this study was to analyze the incidence and pattern of conduction gaps in patients with arrhythmia recurrence after an EAS-guided PVI. METHODS: Repeat ablations after an EAS-guided PVI were analyzed. After PV angiograms, PV reconnection was assessed. Radiofrequency ablation was delivered at the earliest pulmonary vein (PV) activation site (gap) with the goal of PV re-isolation. First, the incidence of reconnected PVs per patient was assessed. Second, the gap pattern according to the individual PV quadrant was analyzed. RESULTS: Fifty-nine out of 373 (16%) patients underwent a second procedure after index EAS. PV reconnection was observed in 71/230 (31%) PVs without statistically significant differences between individual PVs. A higher incidence of gaps was found for right PVs (49 vs. 27; p 0.0006). The carina between the superior and inferior PV presented a low incidence of gaps (18 vs. 56, p < 0.0001). Gaps were also predominant at the AS segment of the RSPV (11 gaps). No predictors of reconnection were found, except the higher total amount of application in the reconnected right inferior PV (26.03 ± 1.30 vs. 32.04 ± 2.89; p 0.0396). CONCLUSION: EAS-guided PVI results in a 72% durable PVI rate in patients with AF recurrences without difference between individual PVs. More of the gap was found in the right PVs especially in the anterosuperior segment of the RSPV.

Complications in Catheter Ablation of Atrial Fibrillation in 3,000 Consecutive Procedures: Balloon Versus Radiofrequency Current Ablation.

OBJECTIVES: The aim of this study was to identify predictors of cardiac tamponade (CT) during atrial fibrillation (AF) ablation using different technologies and strategies. BACKGROUND: The major cause of death during catheter ablation of AF is related to CT. The risk for CT may be linked to different procedural steps (transseptal puncture, catheter manipulation during left atrial and pulmonary vein mapping and ablation). METHODS: All AF ablation procedures undertaken from May 2010 to July 2015 at a single center were included. Two ablation groups were defined: group A, radiofrequency current, and group B, balloon. Group A was divided into groups A1 (pulmonary vein isolation [PVI] only) and A2 (PVI plus additional ablation). In group A, 2 transseptal punctures were performed, followed by wide-area circumferential point-by-point PVI (group A1) within a 3-dimensional left atrial map and complex fractionated atrial electrograms and/or linear lesions (group A2). In group B, 1 transseptal puncture by balloon-based PVI (cryoballoon, laser balloon). All episodes of CT were analyzed. RESULTS: In total, 3,000 AF ablation procedures were performed, 2,125 in group A (group A1, n = 1,559; group A2, n = 566) and 875 in group B (cryoballoon, n = 589; laser balloon, n = 286). The rate of CT was 1.1% (32 of 3,000) and was significantly lower in group B than in group A: 0.1% (1 of 875) versus 1.5% (31 of 2,125) (p = 0.001). The reduced CT risk remained if PVI only (group B vs. group A1) was compared: 0.8% (13 of 1,559) versus 0.1% (1 of 875) (p = 0.024). The greatest CT risk was seen in group A2: 3.2% (18 of 566). Radiofrequency current ablation beyond PVI was a predictor of CT. CONCLUSIONS: The risk for CT in patients undergoing AF ablation at a single high-volume center was decreased with the use of balloon catheters. Extensive radiofrequency current ablation beyond PVI leads to an increased perforation risk.

What Is the Acute Antral Lesion Size After Pulmonary Vein Isolation Using Different Balloon Ablation Technologies?

BACKGROUND: Clinical outcome after pulmonary vein isolation (PVI) may be linked to both durability of PVI and the antral lesion size. Data on balloon-guided technologies are scarce. We investigated the size of the isolated surface area (ISA) acutely after PVI achieved by cryoballoon (CB) or laser balloon (LB), both using voltage mapping.Methods and Results:In 40 patients (73% male, mean age 66±9 years), a bipolar voltage map before and after PVI in sinus rhythm was acquired to delineate the isolated antral surface area (IASA, contiguous area of low voltage <0.5 mV) and the ISA (relative size of the low-voltage area in relation to the whole antral surface area including the posterior wall). IASA (CB: 57±14 cm2vs. LB: 42±15 cm2; P=0.002) as well as ISA (65±8% vs. 54±10%; P=0.001) were significantly larger in the CB than in the LB group. No periprocedural complications occurred. During a mean follow-up of 326±142 days, 4/20 and 5/20 patients experienced an AF/AT recurrence in the CB and LB groups, respectively. No differences in clinical outcome were observed between patients with a large (≥55%) or small (<55%) ISA. CONCLUSIONS: Balloon-guided PVI is associated with antral lesion formation. CB-guided PVI is associated with the largest ISA as compared with LB procedures. ISA size did not correlate with clinical outcome after a single procedure in the present study population.

Individualized cryoballoon energy pulmonary vein isolation guided by real-time pulmonary vein recordings, the randomized ICE-T trial.

BACKGROUND: The ideal energy dosing remains unclear in second-generation cryoballoon (CB) pulmonary vein isolation (PVI). We aimed to investigate the effect of an individualized dosing strategy based on time to PVI (TTI). OBJECTIVE: The purpose of this study was to prospectively investigate the safety and efficacy of individualized PVI using the second-generation CB guided by real-time pulmonary vein recordings. METHODS: Two groups were prospectively randomized: ICE-T group: if TTI <75 seconds, then no bonus freeze; and control group: acute PVI followed by 1 empiric bonus freeze. Freeze duration was set to 240 seconds. The primary end point was single procedure sinus rhythm after 12 months (blanking period 3 months). Secondary end points included procedural data, complications, and biomarker release. RESULTS: In total, 100 patients with paroxysmal atrial fibrillation were randomized. The primary end point was not different (88% vs 82%). Procedure and fluoroscopy times were significantly shorter in the ICE-T group (70 ± 20 minutes vs 89 ± 21 minutes; P < .001 and 10.6 ± 3.9 minutes vs 12.7 ± 5.5 minutes; P = .03). More complications occurred in the control group (n = 9 vs n = 3) (persistent phrenic nerve injury: n = 1 vs n = 0; transient phrenic nerve injury: n = 5 vs n = 2; esophageal lesions: n = 3 vs n = 1). Postablation troponin T levels were not different (ICE-T group vs control group: 1035 ± 402 ng/L vs 1219 ± 509 ng/L; P = .099), whereas a significantly lower lactic acid dehydrogenase release was observed in the ICE-T group (259 ± 47 U/L vs 282 ± 57 U/L; P = .038). Multivariate analysis identified a mean TTI of >43 seconds as the only independent predictor of recurrent atrial tachyarrhythmia. CONCLUSION: The individualized CB PVI strategy allows faster atrial fibrillation ablation without affecting the favorable clinical outcome. A short TTI appears to predict freedom from recurrent atrial tachyarrhythmia.

Procedural characteristics of pulmonary vein isolation using the novel third-generation cryoballoon.

AIM: A novel third-generation cryoballoon (CB3) to perform pulmonary vein isolation (PVI) has recently been released, featuring a shortened distal balloon tip when compared with the second-generation (CB2), possibly allowing for enhanced intra-ablation pulmonary vein (PV) signal mapping. We aimed to investigate procedural efficacy and safety of the CB3 as compared to the CB2. METHODS AND RESULTS: We studied 472 consecutive patients who underwent CB-PVI for paroxysmal or persistent atrial fibrillation (CB3: 49 patients; CB2: 423 patients). Detailed procedural data and in-hospital complications were registered in a prospective database. Complete PVI using the CB only was achieved in 98% of patients in each group. Single-freeze PVI was observed in 84/88% (CB2/CB3, P = n.s.) of the PVs. Time-to-PVI (TPVI) was 49 ± 32 (CB2) and 45 ± 27 s (CB3) (P = n.s.). Time-to-PVI determination rate was higher in the CB3 group (89.5 vs. 82.6%, P = 0.016). Signal noise due to ice formation on mapping electrodes occurred after 70 ± 46 s using CB3 and did not interfere with TPVI determination. Exchange of the spiral mapping catheter with a guide wire was more frequently required in the CB3 group (8.2 vs. 0.7% patients, P < 0.001). Balloon dislodgement during hockey stick manoeuvres occurred in 6.1% patients of the CB3 group only (P = 0.001). Complication rates were not different between the groups. CONCLUSION: The CB3 offers a higher TPVI determination rate, facilitating dosing schemes based on TPVI, with equally high single-freeze efficacy compared with the CB2. The shortened distal tip of the CB3 requires adaptation of standard catheter manoeuvers to avoid balloon dislodgement.

Visually guided pulmonary vein isolation in patients with persistent atrial fibrillation.

AIMS: The role of balloon catheters in patients with persistent forms of atrial fibrillation (AF) remains ill defined. We therefore sought to assess the safety and efficacy of a laser balloon (LB)-guided pulmonary vein isolation (PVI) in consecutive all-comers with persistent AF. METHODS AND RESULTS: All patients undergoing an LB-guided PVI procedure for persistent AF between January 2011 and December 2012 were matched to patients undergoing circumferential PVI using irrigated radiofrequency (RF) current ablation for date of procedure, age, gender, AF duration, left atrial (LA) size, and left ventricular ejection fraction. The primary endpoint was freedom from AF between 90 and 365 days post-ablation after a single procedure. Eighty patients (mean age 66 ± 9; 71% male) with a median (Q1-Q3) AF episode duration of 2 (1-3) months underwent successful PVI in the two groups. The primary endpoint of 1-year single procedure AF/atrial tachycardia (AT) recurrences was reached by 11/40 (27.5%) patients in the LB group and in 9/40 (22.5%) patients in the RF group (P = 0.87). During a mean follow-up of 517 ± 170 days, 13 (32.5%) and 16 (40%) patients in the LB and RF groups, respectively, experienced AF/AT recurrences (P = 0.64). Procedural complications occurred in one patient in the LB group and in six patients in the RF group. CONCLUSION: A subset of patients with drug-refractory persistent AF of short duration benefit from pure PVI without additional substrate modification. A LB-based strategy showed similar outcomes as an irrigated RF-guided circumferential PVI and may be considered an alternative option for the index ablation.

Incidence and characteristics of phrenic nerve palsy following pulmonary vein isolation with the second-generation as compared with the first-generation cryoballoon in 360 consecutive patients.

AIMS: The second-generation cryoballoon (CB2) with increased surface cooling has recently become available. The aim was to investigate the incidence and characteristics of phrenic nerve palsy (PNP) during pulmonary vein isolation (PVI) using the CB2 as compared with the first-generation balloon (CB1). METHODS AND RESULTS: A total of 360 consecutive patients with atrial fibrillation underwent PVI with the CB1 (106 patients) or the CB2 (254 patients). Right PN function was monitored by continuous stimulation and palpation during septal PV ablation. Persistent PNP (present at discharge) occurred in 2.8 and 1.9% (P = 0.63) of patients, transient PNP (full recovery before discharge) in 5.9 and 3.8% (P = 0.41) of patients in the CB2 and CB1 group, respectively. Phrenic nerve palsy during ablation at the right inferior PV was observed in 0% (CB1) and 4.3% (CB2, P = 0.03) of patients. Using the CB2, a trend of reduced incidence of persistent PNP over quartiles of consecutive patients was observed [4.8% (Q1) vs. 0% (Q4); P = 0.077]. At the culprit PV, PNP occurred after 3.5 ± 2.1 (CB1) and 1.1 ± 0.4 applications (CB2; P = 0.036). Complete recovery of PN function occurred after 29 ± 11 (CB1) and 259 ± 137 days (CB2; P = 0.004). CONCLUSIONS: The rate of transient/persistent PNP associated with the use of the CB2 was 5.9 and 2.8%, respectively. Time to restitution of PN function was longer using the CB2.

High rate of durable pulmonary vein isolation after second-generation cryoballoon ablation: analysis of repeat procedures.

AIMS: Pulmonary vein isolation (PVI) using the first-generation cryoballoon (CB1) was characterized by a high rate of recovered pulmonary vein (PV) conduction along with a typical conduction gap pattern in patients with recurrent atrial tachyarrhythmia (ATa). Second generation (CB2) enables more uniform freezing. However, the rate of chronic PVI and PV conduction gap pattern is unknown. METHODS AND RESULTS: All patients with ATa recurrence undergoing a second procedure after CB2 or (historical) CB1 PVI (28 mm) were enrolled. In all patients, a left atrial three-dimensional electronatomic reconstruction was performed. The rates of chronic PVI and localization of PV conduction gaps were determined and compared between CB1 and CB2. Antral PV re-isolation was performed using irrigated-tip radiofrequency current energy ablation. Of 206 patients (CB2), 18 patients underwent the repeat procedure after 192 (75:245) days. In 6 of 18 (33%) patients, all PVs were electrically isolated whereas in the remaining 12 patients (66%) at least one PV demonstrated PV reconduction. Of 71 PVs [1 left common PV (LCPV)], 55 PVs (77%) were chronically isolated. The right superior PV (RSPV) was characterized by the lowest rate of chronic PVI (RSPV: 56%, LSPV: 76%, RIPV: 83%, LIPV: 94%, LCPV: 100%). Compared with CB1, CB2 ablation resulted in a significantly higher rate of chronic PVI (CB2: 77% vs. CB1: 32%; P < 0.0001) with the greatest improvement along both inferior PVs. CONCLUSION: Second-generation cryoballoon atrial fibrillation ablation is associated with a high rate of durable PVI in patients with ATa recurrence. The RSPV represents the PV with the greatest risk for left atrium-pulmonary vein reconnection.

Filling the gap: interventional occlusion of incompletely ligated left atrial appendages.

AIMS: Patients undergoing heart surgery and with history of atrial fibrillation are often treated with intraoperative left atrial appendage (LAA) ligation. Incomplete LAA ligation is often described and can be associated with thrombo-embolic complications. To describe a case series of percutaneous LAA occlusion in patients previously treated with surgical LAA ligation. METHODS AND RESULTS: Over 179 patients treated with implantation of an LAA-occluder system at our centre, 3 (1.6%) were previously treated with a surgical LAA suture exclusion (2 males, age 74 ± 3 years). Patients 1 and 3 presented a 'hammerhead' LAA morphology with an open neck and were successfully treated with an AGA Cardiac Plug (ACP-St Jude Medical) Device. Patient 2 had a conic monolobar LAA with a small neck, and the occlusion could be performed using a Watchman (Boston Scientific) device. After discharge on dual antiplatelet therapy, all the patients could be switched to single aspirin (ASA) therapy after a 6-week transoesophageal echocardiography control. CONCLUSION: Left atrial appendage occlusion in patient with incomplete surgical ligation using percutaneous LAA occluder devices appears to be feasible, and studies including a larger number of patients are needed.

Reduced incidence of esophageal lesions by luminal esophageal temperature-guided second-generation cryoballoon ablation.

BACKGROUND: An increased incidence of esophageal lesions (EL) after pulmonary vein isolation (PVI) using the second-generation cryoballoon (CB2) has been described. We hypothesized that luminal esophageal temperature (LET)-guided PVI reduces the incidence of EL. OBJECTIVE: The aim of this study was to investigate the incidence of EL after LET-guided PVI using the CB2. METHODS: Ninety-four consecutive patients underwent CB2-PVI for paroxysmal or persistent atrial fibrillation. Target freezing time was 2 × 240 seconds. LET was continuously measured by a probe with 3 thermocouples. Early freezing interruption was performed when LET reached a prespecified cutoff temperature. A group of 32 patients who underwent CB2-PVI with observational LET measurement served as the control group. Postprocedural esophagoscopy was performed in all patients. RESULTS: Compared with observational LET measurement, a strategy of LET-guided CB-PVI significantly reduced the incidence of EL from 18.8% to 3.2% (P = .008). A progressive decline in the incidence of EL was observed with an increasing LET cutoff: 7.1% (2/28 patients, 12°C cutoff) and 1.5% (1/66 patients, 15°C cutoff, P = .005 vs control). Despite early freezing interruption at a single pulmonary vein in 27% (25/94) of patients, complete PVI was achieved in all patients using the 28 mm balloon. Repeat esophagoscopy confirmed healing of EL after 1 week. After a mean of 268 ± 119 days, 87% (76/87) of patients were free of recurrent atrial fibrillation or atrial tachycardia following a 90-days blanking period. CONCLUSION: LET-guided CB2-PVI significantly reduced the incidence of thermal EL. Interrupting cryoablation at 15°C LET was associated with the lowest incidence of esophageal injury.

Improved 1-year clinical success rate of pulmonary vein isolation with the second-generation cryoballoon in patients with paroxysmal atrial fibrillation.

BACKGROUND: The second-generation cryoballoon (CB2) has recently been introduced featuring improved surface cooling. Increased procedural efficacy of pulmonary vein isolation (PVI) when compared to the first-generation balloon (CB1) has been reported. The aim of the study was to investigate the clinical outcome of cryoballoon PVI after 1 year using the CB2 as compared to the CB1. METHODS AND RESULTS: A total of 105 consecutive patients with paroxysmal atrial fibrillation (AF) were studied. Cryoballoon PVI (28 mm) was performed in 50 patients using the CB1, and in 55 patients using the CB2. Patients were scheduled for 72-hour Holter ECG recording at 3, 6, 9, and 12 months and every 6 months thereafter. The study endpoint was defined as recurrent AF or atrial tachycardia >30 seconds documented after a blanking period of 90 days after the procedure. Complete PVI was achieved in 49/50 (98%) and 55/55 (100%) patients in the CB1 and CB2 group, respectively. After a mean follow-up of 416 ± 75 days, 21 (CB1 group) and 10 (CB2 group) patients reached the study endpoint. Kaplan-Meier estimates of arrhythmia-free survival after a single procedure without AAD therapy after 1 year were 63.9% versus 83.6% (P = 0.008) in the CB1 and CB2 group, respectively. Persistent phrenic nerve palsy with delayed healing occurred in 2 (CB1 group) and 3 (CB2 group) patients. CONCLUSION: Clinical outcome of PVI using the CB2 was significantly improved when compared to the CB1.

Improved lesion formation using the novel 28 mm cryoballoon in atrial fibrillation ablation: analysis of biomarker release.

AIMS: Recently, a novel second-generation (G2) cryoballoon (CB) was introduced. Comparative analysis of lesion formation in terms of myocardial biomarker release [first-generation CB (G1) vs. G2] has not been studied. To compare myocardial biomarker release using the 28 mm G1 vs. G2 CB. METHODS AND RESULTS: In patients (patients) treated with the simplified single big CB (SBCB) strategy for pulmonary vein isolation (PVI), myocardial biomarkers [troponin T (TnT), creatine kinase, lactic dehydrogenase (LDH)] were measured at 12, 24, and 48 h after PVI. Two groups were defined: Group 1 (G1; freezing time: 300 s), Group 2 (G2; freezing time: 240 s). Mean biomarker peak values were compared. To correct for between-group differences in cumulative freezing time, an index calculated as peak biomarker release divided by cumulative freezing time was calculated. Sixty-six CB PVI procedures (G1: 33 patients, G2: 33 patients) were analysed. Pulmonary vein isolation was achieved in all the patients using the simplified SBCB technique only. Mean freezing time (51 ± 10 vs. 33 ± 6 min, P < 0.01) was significantly shorter in G2. All biomarker levels tended to be higher in G2 vs. G1. The indexed biomarkers values were significantly higher in G2: TnT: 18.8 ± 8.5 vs. 32.3 ± 13.6 pg/L/min (P < 0.01); creatinephosphokinase: 6.7 ± 2.7 vs. 11.7 ± 3.9 U/L/min (P < 0.01); LDH: 5.2 ± 1.0 vs. 9.1 ± 2.7 U/L/min (P < 0.01). On a 6-month follow-up (180 days), G2 revealed a significantly higher success rate (20/33 vs. 28/33; P = 0.027). CONCLUSION: Pulmonary vein isolation using the G2 CB increased the myocardial biomarker release index and is linked to a significantly improved 6 months success rate.

Intraoperative defibrillation threshold testing during implantable cardioverter-defibrillator insertion: do we really need it?

BACKGROUND: The assessment of defibrillation efficacy using a safety margin of 10 J has long been the standard of care for insertion of implantable cardioverter-defibrillator (ICD), but physicians are concerned about complications related to induction test. Therefore, the need for testing has been recently questioned. The aim of our study was to assess the impact of defibrillation threshold (DFT) testing of ICD on the efficacy of ICD therapy. METHODS: We analyzed data obtained from follow-up visits of 122 consecutive patients who underwent ICD implantation at our institute from April 1996 to June 2008, with (n = 42) or without (n = 80) DFT testing. Patients in the DFT group were less likely to be men (83.3% vs 96.3%, P < .031) than those in the non-DFT group. Conversely, the 2 groups were similar in age, left ventricular ejection fraction at baseline, functional class, and underlying cardiovascular disease. Results during a 12-month follow-up, 13 (31.0%) and 30 (37.5%) ventricular tachyarrhythmic episodes were recorded in the DFT and non-DFT groups, respectively (P = .472). Antitachycardia pacing (ATP) terminated most of episodes, reducing the need of defibrillation at 7.7% in the DFT group and 3.3% in the non-DFT group (P = .533). Similar percentages of inappropriate ATP interventions (7.1% vs 3.8%, P = .413) and shock deliveries (2.4% vs 5.0%, P = .659) were recorded between DFT and non-DFT groups. CONCLUSIONS: At 1-year follow-up, the performance of DFT testing does not seem to add any significant efficacy advantage in patients undergoing ICD implantation. Prospective randomized trials and long-term follow-up are warranted to clarify whether routine DFT testing may be safely abandoned leading to a revision of current guidelines.