Johannes Riedl

Durability of wide-area left atrial appendage isolation: Results from extensive catheter ablation for treatment of persistent atrial fibrillation

BACKGROUND Extensive ablation strategies are currently performed in addition to pulmonary vein isolation (PVI) to improve the clinical outcome of patients with drug-refractory persistent atrial fibrillation (AF). Ablation of complex fractionated atrial electrograms (CFAEs), linear lesions, and/or isolation of the left atrial appendage (LAA) are thought to improve arrhythmia-free survival. OBJECTIVE The purpose of this study was to assess the durability of wide-area left atrial appendage isolation (LAAI) achieved by PVI, an anterior line, and a mitral isthmus line. METHODS Seventy-one patients with intentional or incidental LAAI during repeat catheter ablation for treatment of persistent AF were included. The initial ablation strategy was PVI. Additional ablation strategies were performed only if PVI failed to maintain stable sinus rhythm. Durability of LAAI was assessed during a subsequent ablation procedure for arrhythmia recurrences (n = 23) or a subsequent percutaneous LAA closure (n = 48). RESULTS LAAI was performed after a mean of 3 ± 1 procedures. Ablation strategies included circumferential PVI in 71 patients (100%), mitral isthmus line in 64 (90%), anterior line in 60 (85%), CFAE in 27 (38%), and roof line in 13 (18%). LAAI occurred after ablation and bidirectional block of LA linear lesions in 63 patients (89%) and during extensive CFAE ablation in 8 patients (11%). After a median of 105 [61;426] days, the LAA remained electrically isolated in 52 of 71 patients (73%). CONCLUSION Wide-area LAAI after extensive catheter ablation for persistent AF is durable in the majority of patients. The potential clinical benefit of LAAI for maintaining stable sinus rhythm requires further investigation.

Stand-Alone Pulmonary Vein Isolation Versus Pulmonary Vein Isolation With Additional Substrate Modification as Index Ablation Procedures in Patients With Persistent and Long-Standing Persistent Atrial Fibrillation: The Randomized Alster-Lost-AF Trial (Ablation at St. Georg Hospital for Long-Standing Persistent Atrial Fibrillation)

Background— Pulmonary vein isolation (PVI) for persistent atrial fibrillation is associated with limited success rates and often requires multiple procedures to maintain stable sinus rhythm. In the prospective and randomized Alster-Lost-AF trial (Ablation at St. Georg Hospital for Long-Standing Persistent Atrial Fibrillation), we sought to assess, in patients with symptomatic persistent or long-standing persistent atrial fibrillation, the outcomes of initial ablative strategies comprising either stand-alone PVI (PVI-only approach) or a stepwise approach of PVI followed by complex fractionated atrial electrogram ablation and linear ablation (Substrate-modification approach). Methods and Results— Patients were randomized 1:1 to stand-alone PVI or PVI plus substrate modification. The primary study end point was freedom from recurrence of any atrial tachyarrhythmia, outside a 90-day blanking period, at 12 months. A total of 124 patients were enrolled, with 118 patients included in the analysis (61 in the PVI-only group, 57 in the Substrate-modification group). Atrial tachyarrhythmias recurred in 28 PVI-only group patients and 24 Substrate-modification group patients, for 1-year freedom from tachyarrhythmia recurrence after a single ablation procedure of 54% (95% confidence interval, 43%–68%) in the PVI-only and 57% (95% confidence interval, 46%–72%) in the Substrate-modification group (P=0.86). Twenty-four patients in the PVI-only group (39%) and 18 in the Substrate-modification group (32%) were without arrhythmia recurrence and off antiarrhythmic drug therapy at the end of the 12-month follow-up. Conclusions— In patients with persistent and long-standing persistent atrial fibrillation, no significant difference was observed in 12-month freedom from atrial tachyarrhythmias between an index ablative approach of stand-alone PVI and a stepwise approach of PVI plus complex fractionated atrial electrogram and linear ablation. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT00820625.

Three-Year Clinical Outcome After 2nd-Generation Cryoballoon-Based Pulmonary Vein Isolation for the Treatment of Paroxysmal and Persistent Atrial Fibrillation : A 2-Center Experience

BACKGROUND Pulmonary vein isolation (PVI) using the 2nd-generation cryoballoon (CB2) for the treatment of atrial fibrillation (AF) has demonstrated encouraging acute and mid-term results. However, follow-up data on outcomes beyond 1 year are sparse. We investigated the 3-year outcome after PVI using the CB2.Methods and Results:100 patients with paroxysmal (PAF, 70/100 [70%] patients) or persistent AF (pAF, 30/100 [30%] patients) underwent CB2-based PVI in 2 experienced centers in Germany. Freeze-cycle duration was 240 s. After successful PVI a bonus freeze-cycle of the same duration was applied in the first 71 patients but was omitted in the following 29 patients. Phrenic nerve palsy occurred in 3 patients (3%); 2 patients were lost to follow-up. After a median follow-up of 38 (29-50) months, 59/98 (60.2%) patients remained in stable sinus rhythm (PAF: 48/70 (69%), pAF: 11/28 (39%) P=0.0084). In 32/39 (77%) patients with arrhythmia recurrence, a second ablation procedure using radiofrequency energy was conducted. Persistent PVI was noted in 76/125 (61%) PVs. After a mean of 1.37±0.6 procedures and a median follow-up of 35 (25-39) months, 77/98 (78.6%) patients remained in stable sinus rhythm (PAF: 56/70 (80%), pAF: 20/28 (71%), P=0.0276). CONCLUSIONS CB2-based PVI resulted in a 60.2% single-procedure and a 78.6% multiple-procedure success rate after 3 years. Repeat procedures demonstrated a high rate of durable PVI.

First insights into cryoballoon-based pulmonary vein isolation taking the individual time-to-isolation into account

Aims Cryoballoon (CB)-based pulmonary vein isolation (PVI) is an established treatment for symptomatic atrial fibrillation (AF). In the present study, we sought to assess the efficacy and safety of CB-based PVI taking the individual time-to-isolation (TTI) into account. Methods and results Sixty consecutive patients with drug-refractory paroxysmal atrial fibrillation [n = 49 (82%)] or short-standing persistent atrial fibrillation [n = 11 (18%)] underwent ablation with a 28-mm second-generation CB. The TTI was assessed by spiral mapping-catheter recordings and subsequently followed by an additional freeze-time of 120 s. No bonus freeze-cycle was applied. If the TTI could not be assessed, a fixed freeze-cycle duration of 240 s was applied and successful PVI confirmed thereafter. Clinical follow-up (FU) included 12-lead ECGs and 24 h Holter-ECGs at 3, 6, and 12 months. A blanking period of 3 months was defined. A total of 239 pulmonary veins (PVs) were identified and successfully isolated. The mean TTI assessed in 170/239 (71%) PVs was 52 ± 32 s. The mean number of CB applications was 1.2 ± 0.5; mean freeze-cycle duration was 192 ± 41 s. Mean procedure and fluoroscopy times were 80 ± 24 min and 16 ± 7 min, respectively. Transient phrenic nerve palsy occurred in one patient (2%). During a mean FU of 405 ± 67 days, 43 patients (72%) remained in stable sinus rhythm. Conclusions Integrating an individual TTI protocol to CB-based PVI results in shorter freeze-cycle applications in a substantial portion of targeted PVs and an arrhythmia-free survival comparable to conventional ablation protocols. The complication rate is low.

Direct Comparison of Point-by-point and Rapid Ultra High-Resolution Electroanatomical Mapping in Patients Scheduled for Ablation of Atrial Fibrillation.

Three‐dimensional electroanatomical mapping (EAM) is an established tool facilitating catheter ablation. In this context, the novel Rhythmia system sets a new bar in fast high‐resolution mapping. The aim of this study was to directly compare point‐by‐point versus rapid ultra‐high‐resolution EAM in patients scheduled for ablation of atrial fibrillation (AF) with focus on procedural data, acute success, and midterm clinical outcome.

Catheter ablation of atrial fibrillation in very young adults: a 5-year follow-up study

Aims Catheter ablation is an established therapy for symptomatic atrial fibrillation (AF). However, outcome data on catheter ablation for AF in young adults is scarce. Methods and results From 2005-2014, 85 consecutive young adults (mean age 31 ± 4 years; 69% men) with symptomatic paroxysmal AF (PAF, n = 52) and persistent (Pers) AF (n = 33) underwent pulmonary vein isolation (PVI) [±ablation of complex fractionated atrial electrograms/linear lesions in PVI non-responders] at our centre. Follow-up was based on outpatient visits including 24-h Holter-ECG at 3, 6 and, 12 months post ablation, and every 12 months thereafter. Recurrence was defined as any AF/atrial tachycardia episode >30s following a 3-month blanking period. Follow-up was available for 74/85 (87%) patients. After a median follow-up of 4.6 years (Q1: 2.6; Q3: 6.6) and a mean of 1.5 ± 0.6 (median 1, range 1-3) ablation procedures 84% [including 13% on previously ineffective antiarrhythmic drugs (AAD)] of patients were in stable SR. Single-procedural 1-year/5-year arrhythmia-free survival was 66% [95% confidence interval (CI): 56-78%]/44% (95% CI: 33-59%), respectively. Structural heart disease [SHD; hazard ratio (HR) 2.79 (95% CI 1.52-5.12), P = 0.001] and obesity [HR 1.10 (95% CI 1.00-1.21) per unit increase in body mass index >27 kg/m2, P = 0.05] independently predicted AF recurrence. Major complications occurred in 6/122 (4.9%) procedures (PV stenosis in 3, cardiac tamponade in 1, stroke in 1, and arterial-venous fistula in 1). Conclusion In the majority of very young adults catheter ablation for AF is effective, and associated with an acceptable complication rate. SHD and obesity are predictors for AF recurrence in this population.

Significant reduction of radiation exposure in cryoballoon-based pulmonary vein isolation

Aims Procedure times and left atrial dwell times of cryoballoon (CB)-based ablation strategies for atrial fibrillation (AF) are shorter as compared to radiofrequency ablation, yet fluoroscopy times are longer and result in a higher radiation exposure. The objective of this study is to evaluate a modified fluoroscopy protocol aiming at reduction of radiation exposure in CB ablation. Methods and results A total of 120 patients with symptomatic AF underwent pulmonary vein isolation (PVI) using the second generation CB and an ablation strategy considering the individual time-to-isolation. The first 60 patients (Group 1) underwent CB-based PVI with conventional fluoroscopy settings. An optimized approach was applied in the following 60 patients (Group 2) by (i) using fluoroscopy instead of filming for verification of pulmonary vein (PV) occlusion after contrast injection, (ii) reducing the frame rate, and (iii) pursuing maximal collimation on the region of interest. A total of 475 PVs were identified and successfully isolated. Median dose area product and fluoroscopy time were significantly shorter in Group 2 as compared to Group 1 [389 (285; 550) cGycm2 vs. 2168 (1355; 3490) cGycm2 (P < 0.0001) and 10 (8; 12) min vs. 14 (11; 19) min (P < 0.0001)]. Additionally, median time-to-isolation of the PVs was significantly shorter in Group 2 [44 (30; 65) s vs. 33 (20; 46) s (P < 0.0001)]. Conclusions The implementation of an optimized fluoroscopy protocol significantly reduces radiation exposure in CB-based PVI without compromising acute efficacy and safety.

Catheter Ablation of the Superolateral Mitral Isthmus Line: A Novel Approach to Reduce the Need for Epicardial Ablation

Background The mitral isthmus is a critical part of perimitral reentrant tachycardia, as well as an important substrate of persistent atrial fibrillation. Deployment of an endocardial mitral isthmus line (MIL) with the end point of bidirectional block may be challenging and often requires additional epicardial ablation within the coronary sinus. Methods and Results The study population comprised 114 patients with perimitral flutter who underwent de novo ablation of an MIL. The initial 57 patients (group A) underwent catheter ablation using a novel superolateral MIL design, connecting the left-sided pulmonary veins with the mitral annulus along the posterior base of the left atrial appendage visualized by selective angiography. The next 57 patients (group B) served as a control group and underwent ablation using a conventional MIL design, connecting the left inferior pulmonary vein with the mitral annulus. Bidirectional block was achieved in 56 of 57 patients in group A (98.2%) and 50 of 57 patients in group B (87.7%; P=0.06). Deployment of a superolateral MIL required significantly less ablation from within the coronary sinus (7.0% versus 71.9%; P<0.01). Predictors for unsuccessful bidirectional mitral isthmus blockade were the need for epicardial ablation from within the coronary sinus (P<0.01) and the total length of the MIL (29.3±6.35 mm versus 40.8±7.29 mm; P=0.005). A higher rate of pericardial tamponade was observed in group A (5.2% versus 0%; P=0.24). Conclusions The superolateral MIL is associated with a high acute success rate to achieve bidirectional block using endocardial ablation only with minimal need for epicardial ablation from within the coronary sinus.

Prognostic Impact of the Timing of Recurrence of Infarct-Related Ventricular Tachycardia after Catheter Ablation

Background—Recurrence of ventricular tachycardia (VT) after ablation in patients with previous myocardial infarction is associated with adverse prognosis. However, the impact of the timing of VT recurrence on outcomes is unclear. Methods and Results—We analyzed data from a multicenter collaborative database of patients who underwent catheter ablation for infarct-related VT. Multivariable Cox regression analyses investigated the effect of the timing of VT recurrence on the composite outcome of death or heart transplantation using VT recurrence as a time-varying covariate. A total of 1412 patients were included (92% men; age: 66.7±10.7 years), and 605 patients (42.8%) had a recurrence after median 116 days (188 [31.1%] within 1 month, 239 [39.5%] between 1 and 12 months, and 178 [29.4%] after 12 months). At median follow-up of 670 days, 375 patients (26.6%) experienced death or heart transplantation. The median time from recurrence to death or heart transplantation was 65 and 198.5 days in patients with recurrence ⩽30 days and >30 days post ablation, respectively. The adjusted hazard ratio (95% confidence interval) for the effect of VT recurrence occurring immediately post ablation on death or heart transplantation was 3.45 (2.33–5.11) in reference to no recurrence. However, the magnitude of this effect decreased statistically significantly (P<0.001) as recurrence occurred later in the follow-up period. The respective risk estimates for VT recurrence at 30 days, 6 months, 1 year, and 2 years were 3.36 (2.29–4.93), 2.94 (2.09–4.14), 2.50 (1.85–3.37), and 1.81 (1.37–2.40). Conclusions—VT recurrence post ablation is associated with a mortality risk that is highest soon after the ablation and decreases gradually thereafter.

Pace Mapping for the Identification of Focal Atrial Tachycardia Origin A Novel Technique to Map and Ablate Difficult-to-Induce and Nonsustained Focal Atrial Tachycardia

Background—Focal atrial tachycardia (FAT) is extremely difficult to map and ablate when it is difficult to induce and nonsustained. The objective of this study is to evaluate the efficacy of pace mapping in identifying the FAT origin. Methods and Results—The study included 7 patients with drug-refractory FAT who experienced daily multiple episodes before ablation and presented with difficult-to-induce and nonsustained FAT and a distinct P wave morphology. Pace mapping was systematically performed in the areas of interest using 3-dimensional mapping to match the P wave morphology and paced intracardiac activation sequence recorded from multiple catheters. The anatomic origins of FAT were the right pulmonary vein (PV) in 3 patients, mitral annulus, crista terminalis, tricuspid annulus, and right-sided PV via a posterior conduction of previous PV isolation. In all patients, pace mapping obtained best-matched P wave morphology in ≥11/12 leads of surface ECG at the successful ablation site, and paced intracardiac activation sequence was identical to that of induced FAT. Focal ablation was delivered in 4 patients, including non-PV FAT in 3 and FAT in 1, via posterior gap along the previous right-sided PV isolation, and circumferential right-sided PV isolation was performed in the other 3 patients. No FAT was induced at the end of the procedure. All patients were free of arrhythmias without antiarrhythmic drugs during the 8.4±5.6-month follow-up. Conclusions—The combination of paced P wave morphology and intracardiac activation sequence can be used for the identification of FAT origin in patients with difficult-to-induce and nonsustained FAT.