Erik Wissner

Long-Term Results of Catheter Ablation in Paroxysmal Atrial Fibrillation Lessons From a 5-Year Follow-Up

Background— Paroxysmal atrial fibrillation (AF) naturally progresses toward chronic AF at an estimated rate of 15% to 30% over a 1- to 3-year period. Pulmonary vein (PV) isolation is increasingly performed for the treatment of drug-refractory paroxysmal AF. The long-term data on clinical outcome after circumferential PV isolation are limited. Methods and Results— From 2003 to late 2004, 161 patients (121 men; age, 59.8±9.7 years) with symptomatic paroxysmal AF and normal left ventricular function underwent circumferential PV isolation guided by 3-dimensional mapping and double Lasso technique. Right-sided and left-sided continuous circular lesions encircling the ipsilateral PVs were placed with irrigated radiofrequency energy. The procedure end point was the absence of all PV spikes for at least 30 minutes after PV isolation verified by 2 Lasso catheters placed within the ipsilateral PVs. Sinus rhythm was present in 75 patients (46.6%) after the initial procedure during a median follow-up period of 4.8 years (0.33 to 5.5 years). A second procedure was performed in 66 and a third procedure in 12 patients. Recovered PV isolation conduction was observed in 62 of 66 patients (94.0%) during the second and in 8 of 12 patients (66.7%) during the third procedure. After a median of 1 (1 to 3) procedure, stable sinus rhythm was achieved in 128 of 161 patients (79.5%), whereas clinical improvement occurred in an additional 21 of 161 patients (13.0%) during a median follow-up of 4.6 years (0.33 to 5.5 years). Four patients in stable sinus rhythm died during follow-up. Progression toward chronic AF was observed in 4 patients (2.4%); however, only 2 patients reported symptoms. Conclusion— In patients with paroxysmal AF and normal left ventricular function, circumferential PV isolation results in stable sinus rhythm in the majority of patients, and low incidence of chronic AF was observed after ablation during up to 5 years of follow-up.

Catheter Ablation of Long-Standing Persistent Atrial Fibrillation: 5-Year Outcomes of the Hamburg Sequential Ablation Strategy

OBJECTIVES This study describes the 5-year efficacy of catheter ablation for long-standing persistent atrial fibrillation (LS-AF). BACKGROUND Long-term outcome data after catheter ablation for LS-AF are limited. METHODS Long-term follow-up of 56 months (range 49 to 67 months) was performed in 202 patients (age 61 ± 9 years) who underwent the sequential ablation strategy for symptomatic LS-AF. Initial ablation strategy was circumferential pulmonary vein isolation (PVI). Additional ablation was performed only in acute PVI nonresponder, if direct current cardioversion failed after PVI. RESULTS After the first ablation procedure, sinus rhythm was documented in 41 of 202 (20.3%) patients. After multiple procedures, sinus rhythm was maintained in 91 of 202 (45.0%) patients, including 24 patients receiving antiarrhythmic drugs. In 105 patients, PVI was the sole ablative therapy, 49 (46.7%) of those patients remained in sinus rhythm during follow-up. Patients with a total AF duration of <2 years had a significantly higher ablation success rate than patients whose AF duration was >2 years (76.5% vs. 42.2%, respectively; p = 0.033). Persistent AF duration (hazard ratio: 1.09 [95% confidence interval: 1.04 to 1.13]; p < 0.001) independently predicted arrhythmia recurrences, and acute PVI responders had a reduced risk of relapse (hazard ratio: 0.57 [95% confidence interval: 0.41 to 0.78]; p < 0.001) after the first ablation. CONCLUSIONS During 5-year follow-up, single- and multiple ablation procedure success was 20% and 45%, respectively, for patients with LS-AF. For patients with a total AF duration of <2 years, the outcomes were favorable.

Electrical reconnection after pulmonary vein isolation is contingent on contact force during initial treatment: results from the EFFICAS I study

Background—Pulmonary vein isolation is the most prevalent approach for catheter ablation of paroxysmal atrial fibrillation. Long-term success of the procedure is diminished by arrhythmia recurrences occurring predominantly because of reconnections in previously isolated pulmonary veins. The aim of the EFFICAS I multicenter study was to demonstrate the correlation between contact force (CF) parameters during initial procedure and the incidence of isolation gaps (gap) at 3-month follow-up. Method and Results—A radiofrequency ablation catheter with integrated CF sensor (TactiCath, Endosense, Geneva, Switzerland) was used to perform pulmonary vein isolation in 46 patients with paroxysmal atrial fibrillation. During the ablation procedure, the operator was blinded to CF information. At follow-up, an interventional diagnostic procedure was performed to assess gap location as correlated to index procedure ablation parameters. At follow-up, 65% (26/40) of patients showed ≥1 gaps. Ablations with minimum Force–Time Integral (FTI) <400 gs showed increased likelihood for reconnection (P<0.001). Reconnection correlated strongly with minimum CF (P<0.0001) and minimum FTI (P=0.0007) at the site of gap. Gap occurrence showed a strong trend with lower average CF and average FTI. CF and FTI are generally higher on the right side, although the left anterior segment presents a unique challenge to achieve stable position with good CF. Conclusions—Minimum CF and minimum FTI values are strong predictors of gap formation. Optimal CF parameter recommendations are a target CF of 20 g and a minimum FTI of 400 gs for each new lesion.

One-Year Clinical Outcome After Pulmonary Vein Isolation Using the Second-Generation 28-mm Cryoballoon

Background—The use of second-generation cryoballoon for pulmonary vein isolation in patients with paroxysmal atrial fibrillation has demonstrated encouraging acute and mid-term results. Long-term outcome data are not yet available. Methods and Results—Fifty patients (18 women; mean age, 61±11 years; mean left atrial diameter, 43±5 mm) with paroxysmal (36 of 50 patients; 72%) or short-standing (<3-month duration) persistent atrial fibrillation (14 of 50 patients; 28%) underwent cryoballoon-based pulmonary vein isolation. Freeze cycle duration was 240 seconds. After successful pulmonary vein isolation, a bonus freeze was applied. Follow-up was based on outpatient clinic visits at 3, 6, and 12 months including Holter-ECGs and telephonic interviews. Recurrence was defined as a symptomatic or documented arrhythmia episode >30 seconds excluding a 3-month blanking period. A total of 192 pulmonary veins were identified, and 191 of 192 (99%) pulmonary veins were successfully isolated. Phrenic nerve palsy occurred in 1 of 50 (2%) patients. Follow-up was available for 49 of 50 (98%) patients with a mean follow-up duration of 440±39 days. Thirty-nine of 49 (80%) patients remained in stable sinus rhythm. Of 8 of 10 patients with arrhythmia recurrence, a second procedure using radiofrequency ablation demonstrated left atrial to pulmonary vein reconduction. Conclusions—The use of second-generation 28-mm cryoballoon for pulmonary vein isolation results in an 80% 1-year success rate.

Electrical Reconnection After Pulmonary Vein Isolation Is Contingent on Contact Force During Initial TreatmentClinical Perspective

Background—Pulmonary vein isolation is the most prevalent approach for catheter ablation of paroxysmal atrial fibrillation. Long-term success of the procedure is diminished by arrhythmia recurrences occurring predominantly because of reconnections in previously isolated pulmonary veins. The aim of the EFFICAS I multicenter study was to demonstrate the correlation between contact force (CF) parameters during initial procedure and the incidence of isolation gaps (gap) at 3-month follow-up. Method and Results—A radiofrequency ablation catheter with integrated CF sensor (TactiCath, Endosense, Geneva, Switzerland) was used to perform pulmonary vein isolation in 46 patients with paroxysmal atrial fibrillation. During the ablation procedure, the operator was blinded to CF information. At follow-up, an interventional diagnostic procedure was performed to assess gap location as correlated to index procedure ablation parameters. At follow-up, 65% (26/40) of patients showed ≥1 gaps. Ablations with minimum Force–Time Integral (FTI) <400 gs showed increased likelihood for reconnection (P<0.001). Reconnection correlated strongly with minimum CF (P<0.0001) and minimum FTI (P=0.0007) at the site of gap. Gap occurrence showed a strong trend with lower average CF and average FTI. CF and FTI are generally higher on the right side, although the left anterior segment presents a unique challenge to achieve stable position with good CF. Conclusions—Minimum CF and minimum FTI values are strong predictors of gap formation. Optimal CF parameter recommendations are a target CF of 20 g and a minimum FTI of 400 gs for each new lesion.

EFFICAS II: optimization of catheter contact force improves outcome of pulmonary vein isolation for paroxysmal atrial fibrillation

Aims A challenge of pulmonary vein isolation (PVI) in catheter ablation for paroxysmal atrial fibrillation (PAF) is electrical reconnection of the PV. EFFICAS I showed correlation between contact force (CF) parameters and PV durable isolation but no prospective evaluation was made. EFFICAS II was a multicentre study to prospectively assess the impact of CF guidance for an effective reduction of PVI gaps. Methods and results Pulmonary vein isolation using a radiofrequency (RF) ablation catheter with an integrated force sensor (TactiCath™) was performed in patients with PAF. Operators were provided EFFICAS I-based CF guidelines [target 20 g, range 10–30 g, minimum 400 g s force-time integral (FTI)]. Conduction gaps were assessed by remapping of PVs after 3 months, and gap rate was compared with EFFICAS I outcome. At follow up, 24 patients had 85% of PVs remaining isolated, compared with 72% in EFFICAS I (P = 0.037) in which CF guidelines were not used. The remaining 15% of gaps correlated to the number of catheter moves at creating the PVI line, quantified as Continuity Index. For PV lines with contiguous lesions and low catheter moves, durable isolation was 81% in EFFICAS I and 98% in EFFICAS II (P = 0.005). At index procedure, the number of lesions was reduced by 15% in EFFICAS II vs. EFFICAS I. Conclusion The use of CF with the above guidelines and contiguous deployment of RF lesions in EFFICAS II study resulted in more durable PVI in catheter ablation of PAF.

Increased incidence of esophageal thermal lesions using the second-generation 28-mm cryoballoon.

Background—Pulmonary vein isolation is an established treatment option for atrial fibrillation. To date, the incidence and quality of ablation-induced esophageal thermal lesions (ETLs) using the recently introduced second-generation cryoballoon (CB, ArcticFront Advance, Medtronic) is unknown. Methods and Results—In patients with drug-refractory paroxysmal atrial fibrillation or short-standing persistent atrial fibrillation, pulmonary vein (PV) isolation was performed using the second-generation CB. The endoluminal esophageal temperature was monitored via a temperature probe. After PV isolation, esophagogastroduodenoscopy (EGD) was performed to assess the incidence of ETLs. In 50 patients (18 women; age, 61±11 years; left atrial diameter, 43±5 mm), successful CB-based PV isolation was performed. Lowest median balloon temperature and esophageal temperature for the right superior PV were −51°C and 35.8°C, −47°C and 35°C for the right inferior PV, −51°C and 34.4°C for the left superior PV, −48°C and 34.6°C for the left inferior PV, and −54°C and 34.5°C for the left common PV, respectively. EGD performed 2±1 days post ablation demonstrated superficial thermal lesions and thermal ulcerations in 1 of 50 (2%) and 5 of 50 (10%) patients, respectively. In patients with ETLs, during ≥1 freeze cycle the endoluminal esophageal temperature measured <3.0°C. All thermal lesions were in the healing process on repeat EGD 4±2 days after initial endoscopy. Conclusions—Using the second-generation 28-mm CB, ETLs were detected in 6 of 50 (12%) patients. All ETLs were in the healing process on repeat EGD. An esophageal temperature safety cutoff may prove valuable in the prevention of ETLs and requires further evaluation.

Feasibility of circumferential pulmonary vein isolation using a novel endoscopic ablation system.

Background—Pulmonary vein isolation (PVI) is an established treatment option for patients with drug refractory paroxysmal atrial fibrillation. A novel compliant endoscopic ablation system housing a 980-nm-diode laser allows for discrete point-by-point ablation enabling a true circumferential ablation line design. We sought to determine the feasibility and safety of a circumferential ablation using endoscopic ablation system. Methods and Results—Thirty patients (17 female; mean age, 58±9 years) with a median paroxysmal atrial fibrillation history of 3 years (range, 1 to 17 years) were treated. PVI was achieved in 114 of 116 (98%) PVs (4 left common PVs), thereby achieving simultaneous PVI for separate ipsilateral PVs in 19 of 26 (73%) left PVs and 6 of 30 (20%) right PVs. The total procedure time was 250±62 minutes. Procedure time decreased from 310±59 to 220±37 minutes (P=0.0001) between the first 10 and the last 20 cases. Mean fluoroscopy time was 30±18 minutes. Twenty-seven patients underwent postoperative endoscopy showing no or minimal thermal lesions in the esophagus in 21 (78%) and 2 (7%), respectively. In 4 (15%) patients, an esophageal ulceration was found that healed without sequelae. One pericardial tamponade and 1 right-sided phrenic nerve palsy occurred. During a median follow-up of 168 days (113 to 203 days; q1-q3), 24 of 30 patients (80%) remained free of atrial fibrillation recurrence. Conclusions—Circumferential PVI using the novel compliant endoscopic ablation system was feasible in the majority of left PVs and minority of right PVs accompanied by a complication rate comparable to established approaches. To minimize the risk for thermal esophageal injury temperature monitoring is recommended.

Catheter ablation of ventricular tachycardia in ischaemic and non-ischaemic cardiomyopathy: where are we today? A clinical review

According to the current guidelines, patients with ischaemic cardiomyopathy (ICM) or non-ischaemic cardiomyopathy (NICM) at risk for sudden cardiac death should undergo implantation of an implantable cardioverter-defibrillator (ICD). Although ICDs effectively terminate ventricular arrhythmias, the arrhythmogenic substrate remains unchanged or may progress over time, resulting in recurrent ICD shocks. Defibrillator shocks increase mortality and worsen quality of life. Evidence from two prospective randomized trials on outcome in patients with ischaemic heart disease undergoing catheter ablation for ventricular tachycardia (VT) suggests that ablation prevents recurrence of VT and decreases the number of ICD shocks. This review will highlight the recent progress made in the ablative treatment of VT in patients with ICM and NICM.

Cryoballoon Pulmonary Vein Isolation with Real-Time Recordings from the Pulmonary Veins

Introduction: Cryoballoon (CB) ablation represents a novel technology for pulmonary vein isolation (PVI). We investigated feasibility and safety of CB‐PVI, utilizing a novel spiral catheter (SC), thereby obtaining real‐time PV potential registration.