Individually tailored vs. standardized substrate modification during radiofrequency catheter ablation for atrial fibrillation: a randomized study.

Aims: This randomized single-centre study sought to compare the efficacy and safety of pulmonary vein isolation (PVI) plus voltage-guided ablation vs. PVI with or without linear ablation depending on the type of atrial fibrillation (AF). Methods and results: Overall, 124 ablation-naive patients with paroxysmal or persistent AF were randomized to PVI with (persistent AF) or without (paroxysmal AF) additional linear ablation (control group) vs. PVI plus ablation of low-voltage areas (LVAs) irrespective of AF type. Bipolar voltage mapping was performed during stable sinus rhythm. An LVA consisted of ≥ 3 adjacent mapping points that each had a peak-to-peak amplitude ≤0.5 mV. After a mean follow-up of 12 ± 3 months, significantly more patients in the LVA ablation group were free from atrial arrhythmia recurrence >30 s off antiarrhythmic drugs (AADs) after a single procedure (primary endpoint) compared with control group patients [40/59 (68%) vs. 25/59 (42%), log-rank P = 0.003]. Arrhythmia-free survival on or off AADs was found in 33/59 control group patients (56%) and in 41/59 LVA ablation group patients (70%) (adjusted log-rank P = 0.10). During the 7 day Holter monitoring period at 12 months, significantly more patients in the LVA ablation group were free from arrhythmia recurrence on or off AADs [45/50 (90%) vs. 33/46 (72%), P = 0.04]. No between-group differences were observed regarding procedure duration, fluoroscopy time, and major complications. Conclusion: In this single-centre study, individually tailored substrate modification guided by voltage mapping was associated with a significantly higher arrhythmia-free survival rate compared with a conventional approach applying linear ablation according to AF type.

Long-term comparison of cryoballoon and radiofrequency ablation of paroxysmal atrial fibrillation: a propensity score matched analysis.

BACKGROUND: Although radiofrequency (RF) and cryoballoon (CB) based technologies for pulmonary vein isolation (PVI) have both individually been demonstrated to be effective and safe for the treatment of paroxysmal AF, head-to-head comparisons are lacking. The purpose of this study was to compare the outcome of cryoballoon versus radiofrequency ablation in patients with paroxysmal atrial fibrillation undergoing pulmonary vein isolation. METHODS: Out of a prospective registry of 327 patients undergoing PVI, 208 patients (age 58±11 years, ejection fraction 59±6%, left atrial size 39±6 mm) with paroxysmal AF were identified. The presented dataset was obtained by 1:1 propensity score matching and contained 142 patients undergoing CB-PVI or RF-PVI in conjunction with a 3D mapping system, respectively. We compared single procedure efficacy of the two methods using a Cox proportional hazards model. RESULTS: After a mean follow-up of 28 months and a single procedure, AF recurred in 37 of 71 (52%) in the CB-PVI group and in 31 of 71 patients (44%) in the RF-PVI group (HR [95% CI]=1.19 [0.74, 1.92], p=0.48). Recurrence of AF for PVI using solely the CB was observed in 23 of 51 (45%) patients and in 23 of 51 (45%) patients in the corresponding RF-PVI group (HR [95% CI]=0.93 [0.52, 1.66], p=0.81). Complication rate was not different between the groups. CONCLUSION: A propensity score matched comparison between CB-PVI and RF-PVI using a 3D-mapping system for AF ablation showed similar long-term success rates.

Tailored atrial substrate modification based on low-voltage areas in catheter ablation of atrial fibrillation.

BACKGROUND: Reduced electrogram amplitude has been shown to correlate with diseased myocardium. We describe a novel individualized approach for catheter ablation of atrial fibrillation (AF) based on low-voltage areas (LVAs) in the left atrium (LA). We sought to assess (1) the incidence of LVAs in patients undergoing AF catheter ablation, (2) the distribution of LVAs within the LA, and (3) the effect of an individualized ablation strategy on long-term rhythm outcomes. METHODS AND RESULTS: In 178 patients with paroxysmal or persistent AF, LA voltage maps were created during sinus rhythm after circumferential pulmonary vein isolation. Subsequent substrate modification was confined to the presence of LVA (<0.5 mV) and inducible regular atrial tachycardias. LVAs were identified in 35% and 10% of patients with persistent and paroxysmal AF, respectively. The LA roof and the anterior, septal, and posterior wall LA were most often affected. The 12-month atrial tachycardias/AF-free survival was 62% for patients without LVAs and 70% for patients with LVAs and tailored substrate modification (P=0.3). Success rate in a comparison group of 26 LVA patients without further substrate modification was 27%. CONCLUSIONS: LVAs can be found at preferred sites in 10% of patients with paroxysmal AF and in 35% of patients with persistent AF. This is the first clinical report describing a consistent voltage-based approach for substrate modification in addition to circumferential pulmonary vein isolation irrespective of AF type. Application of this limited individualized approach may have the potential to compensate for the impaired 12-month outcome of patients with endocardial structural defects.

Sustained monomorphic left ventricular outflow tract tachycardia early after aortic valve replacement.

Sustained monomorphic ventricular tachycardia (VT) after valve surgery is uncommon. Cases of focal VT or bundle-branch re-entry after aortic valve surgery have been reported. We present the case of a 60 year-old patient with an incessant outflow tract VT early after aortic valve replacement. We suggest the disease process affecting the valve and adjacent area, and/or the surgical procedure, might somehow relate to VT substrate adjacent to the aortic annulus.

Long-term efficacy of single procedure remote magnetic catheter navigation for ablation of ischemic ventricular tachycardia: a retrospective study.

BACKGROUND: Remote magnetic navigation (RMN) aims to reduce some inherent limitations of manual radiofrequency (RF) ablation. However, data comparing the effectiveness of both methods are scarce. This study evaluated the acute and long-term success of RMN guided versus manual RF ablation in patients with ischemic sustained ventricular tachycardia (sVT). METHODS: One hundred two consecutive patients (age 68 ± 10 years, LVEF 32 ± 12%, 88 men) with ischemic sVT were ablated with RMN (Stereotaxis; 49%) or manually (51%) using substrate and/or activation mapping (Carto) and open-irrigated-tip catheters. All received implantable defibrillators or loop recorders. Acute success was defined as noninducibility of any sVT at the end of the ablation procedure and long-term success as freedom from VT upon follow-up. RESULTS: There was no difference in the baseline characteristics between the groups. Three patients died in hospital. Acute success rate was similar for RMN and manual ablation (82% vs 71%, P = 0.246). RMN was associated with significantly shorter fluoroscopy time (13 ± 12 minutes vs 32 ± 17 minutes, P = 0.0001) and RF time (2337.59 ± 1248.22 seconds vs 1589.95 ± 1047.42 seconds, P = 0.049), although total procedure time was similar (157 ± 40 minutes vs 148 ± 50 minutes, P = 0.42). There was a nonsignificant trend toward better long-term success in RMN group: after a median of 13 (range 1-34) months, 63% in the RMN and 53% in the manual ablation group were free from VT recurrence (P = 0.206). CONCLUSION: RMN guided RF ablation of ischemic sustained VT is equally efficient compared with manual ablation in terms of acute and long-term success rate. These results are achieved with a significantly reduced fluoroscopy time and shorter RF time.

Cryoballoon versus radiofrequency catheter ablation of paroxysmal atrial fibrillation: biomarkers of myocardial injury, recurrence rates, and pulmonary vein reconnection patterns.

BACKGROUND: Cryoballoon ablation has emerged as a novel treatment strategy for patients with atrial fibrillation (AF). OBJECTIVE: The purpose of this study was to compare pulmonary vein isolation (PVI) using cryoballoon ablation versus RF ablation with regard to myocardial injury, pulmonary vein (PV) reconnection patterns, and outcome. METHODS: Fifty patients (age 59 ± 9 years, ejection fraction 0.59 ± 0.06, left atrial size 41 ± 5 mm) with paroxysmal AF were studied. Twenty-five patients underwent PVI using a 28-mm cryoballoon. A control group of 25 patients underwent PVI using an open-irrigation RF ablation catheter. Myocardial injury was determined by measuring troponin T (TnT). PV reconnection patterns were studied in case of repeat procedures. RESULTS: Procedure duration was 166 ± 32 minutes in the cryoballoon group versus 197 ± 52 minutes in the RF group (P = .014), with similar ablation times (cryoballoon: 45 minutes [interquartile range 40-52.5 minutes]; RF: 47 minutes [interquartile range 44-65 minutes], P = .17). Postprocedural TnT in the RF group was 1.29 ± 0.41 µg/L versus 0.76 ± 0.55 µg/L in the cryoballoon group (P = .002). In 12 patients who underwent repeat ablation, 74% of PV reconnection sites were inferiorly located in the cryoballoon group compared to 17% in the RF group (P = .0004). With 1.2 ± 0.4 and 1.3 ± 0.6 procedures per patient, 88% of patients in the cryoballoon group and 92% in the RF group were in stable sinus rhythm after follow-up of 12 ± 3 months (P = NS). CONCLUSION: Differences in the extent of myocardial injury and patterns of PV reconnection were observed between cryoballoon ablation and RF ablation of paroxysmal AF.