Impact of atrial fibrillation phenotype and left atrial volume on outcome after pulmonary vein isolation.

AIMS: Pulmonary vein isolation (PVI) is increasingly performed in patients with atrial fibrillation (AF). Both AF phenotype and left atrial (LA) volume have been shown to influence ablation outcome. The inter-relationship of the two is incompletely understood. We aimed to investigate the impact of AF phenotype vs. LA volume on outcome after PVI. METHODS AND RESULTS: In a retrospective analysis of a prospective registry of patients undergoing a first PVI, the association of AF phenotype and LA volume index (LAVI) was assessed as well as their impact on AF recurrence during follow-up. Overall, 476 patients were enrolled (median age 63 years, 29% females, 65.8% paroxysmal AF). Obesity, hypertension, chronic kidney disease, and heart failure were all significantly more frequent in persistent AF. After 1 year, single-procedure, freedom from arrhythmia recurrence was 61.5%. Patients with paroxysmal AF had better outcomes compared with patients with persistent AF (65.6 vs. 52.7%, P = 0.003), as had patients with no/mild vs. moderate/severe LA dilation (LAVI <42 mL/m2 67.1% vs. LAVI ≥42 mL/m2 53%, P < 0.001). The combination of both parameters refined prediction of 1-year recurrence (P < 0.001). After adjustment for additional clinical risk factors in multivariable Cox proportional hazard analysis, both AF phenotype and LAVI ≥42 mL/m2 contributed significantly towards the prediction of 1-year recurrence. CONCLUSION: Atrial fibrillation phenotype and LA volume are independent predictors of outcome after PVI. Persistent AF with no/mild LA dilation has a similar risk of recurrence as paroxysmal AF with a moderate/severe LA dilation and should be given similar priority for ablation.

Epicardial adipose tissue dispersion at CT and recurrent atrial fibrillation after pulmonary vein isolation.

OBJECTIVES: Epicardial adipose tissue (EAT) remodeling is associated with atrial fibrillation (AF). Left atrial (LA) EAT dispersion on cardiac CT is a non-invasive imaging biomarker reflecting EAT heterogeneity. We aimed to investigate the association of LA EAT dispersion with AF recurrence after pulmonary vein isolation (PVI). METHODS: In a prospective registry of consecutive patients undergoing first PVI, mean EAT attenuation values were measured on contrast-enhanced cardiac CT scans in Hounsfield units (HU) within low (- 195 to - 45 HU) and high (- 44 to - 15 HU) threshold EAT compartments around the left atrium (LA). EAT dispersion was defined as the difference between the mean HU values within the two EAT compartments. Continuous variables were compared between groups using the Mann-Whitney U test and cox proportional hazard models were used to calculate hazard ratios of predictors of 1-year AF recurrence. RESULTS: A total of 208 patients were included, 135 with paroxysmal AF and 73 with persistent AF. LA EAT dispersion was significantly larger in patients with persistent compared to paroxysmal AF (52.6 HU vs. 49.9 HU; p = 0.001). After 1 year of follow-up, LA EAT dispersion above the mean (> 50.8 HU) was associated with a higher risk of AF recurrence (HR 2.3, 95% CI 1.5-3.6; p < 0.001). It retained its predictive value when corrected for age, sex, body mass index, LA volume, and AF type (HR 2.8, 95% CI 1.6-4.6; p < 0.001). CONCLUSION: A larger LA EAT dispersion on contrast-enhanced cardiac CT scans, reflecting EAT heterogeneity, is independently associated with AF recurrence after PVI. CLINICAL RELEVANCE STATEMENT: Based on LA EAT dispersion assessment, a more accurate risk stratification and patient selection may be possible based on a pre-procedural cardiac CT when planning PVI. KEY POINTS: • Epicardial adipose tissue (EAT) remodeling is associated with atrial fibrillation (AF). • A larger left atrial EAT dispersion in a pre-procedural cardiac CT was associated with a higher 1-year AF recurrence risk after pulmonary vein isolation. • A pre-procedural cardiac CT with left atrial EAT dispersion assessment may provide a more accurate risk stratification and patient selection for PVI.

The Relationship between Enhancing Left Atrial Adipose Tissue at CT and Recurrent Atrial Fibrillation.

Background The association of epicardial adipose tissue (EAT) and its metabolic activity with atrial fibrillation (AF) is an area of active investigation. Left atrial (LA) enhancing EAT (e-EAT) at cardiac CT may be a noninvasive surrogate marker for the metabolic activity of EAT. Purpose To determine the relationship between LA e-EAT and recurrence after AF ablation. Materials and Methods In a secondary analysis of a prospective registry of consecutive patients (from July 2018 to December 2019) undergoing first AF ablation, total and LA EAT were segmented on preprocedural noncontrast- and contrast-enhanced cardiac CT scans. LA e-EAT volume fraction was defined as the LA EAT volume difference between the noncontrast- and contrast-enhanced scan divided by the total LA EAT volume on the noncontrast-enhanced scan (threshold values, -15 HU to -195 HU). Continuous variables were compared between groups by using the Mann-Whitney U test. Cox proportional hazard models were used to calculate hazard ratios of predictors of 1-year AF recurrence. Results A total of 212 patients (mean age, 64 years; 159 men) who underwent a first AF ablation were included (paroxysmal AF, 64%; persistent AF, 36%). The LA EAT volume was higher in patients with persistent versus paroxysmal AF (50 cm3 [IQR, 37-72] vs 37 [IQR, 27-49]; P < .001), but no difference was found for LA e-EAT (P = .09). After 1 year of follow-up, AF recurrence rate was 77 of 212 (36%). LA e-EAT above the mean (>33%) was associated with a higher risk of AF recurrence (hazard ratio [HR], 2.1; 95% CI: 1.3, 3.3; P < .01). In a multivariable Cox regression analysis, LA e-EAT retained its predictive value when corrected for sex, age, AF phenotype, LA volume index, and LA EAT volume (HR, 1.9; 95% CI: 1.1, 3.1; P = .02). Conclusion Left atrial enhancing epicardial adipose tissue was independently associated with recurrence after atrial fibrillation ablation. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Stojanovska in this issue.

Efficacy and safety of a novel cryoballoon ablation system: multicentre comparison of 1-year outcome.

AIMS: The aim of the study was to compare the 1-year efficacy and safety of a novel cryoballoon (NCB) ablation system (POLARx; Boston Scientific) for pulmonary vein isolation (PVI) compared with the standard cryoballoon (SCB) system (Arctic Front, Medtronic). METHODS AND RESULTS: Consecutive patients with atrial fibrillation (AF) undergoing PVI using the NCB and the SCB at two centres were included. We report 1-year efficacy after 12 months, short-term safety and hospitalizations within the blanking period, and predictors for AF recurrence. In case of repeat procedures, pulmonary vein (PV) reconnection patterns were characterized. Eighty patients (age 66 ± 10 years, ejection fraction 57 ± 10%, left atrial volume index 39 ± 13 mL/m2, paroxysmal AF in 64%) were studied. After a single procedure and a follow-up of 12 months, 68% in the NCB group and 70% in the SCB group showed no recurrence of AF/atrial tachycardias (P = 0.422). One patient in the NCB group suffered a periprocedural stroke with full recovery. There were no differences regarding hospitalizations during follow-up between the groups. PV reconnection observed during 12 repeat procedures (4 NCB, 8 SCB) pattern was comparable between the groups with more reconnections in the right-sided compared with the left-sided PVs. CONCLUSION: In this multicentre study comparing two currently available cryoballoon ablation systems for PVI, no differences were observed in the efficacy and safety during a follow-up of 12 months.

Technical and procedural comparison of two different cryoballoon ablation systems in patients with atrial fibrillation.

PURPOSE: The aim was to report procedural and technical differences of a novel cryoballoon (NCB) ablation catheter for pulmonary vein isolation (PVI) compared to the standard cryoballoon (SCB) catheter. METHODS: Consecutive patients with atrial fibrillation (AF) undergoing PVI using the NCB and the SCB were included. Procedural parameters, technical differences, acute efficacy, and safety are reported. RESULTS: Eighty patients (age 66 ± 10 years, ejection fraction 57 ± 10%, left atrial volume index 40 ± 6 ml/m2) were studied. With the NCB, 156 of 158 PVs (99%) were isolated compared to isolation of 159 of 159 PVs (100%) with the SCB. The median number of freezes in the NCB and the SCB group was 6 (IQR 5-8) and 5 (IQR 4-7), respectively (p = 0.051), with 73% and 71% of the PVs isolated with a single freeze, respectively. Nadir temperature and temperature at isolation were - 59 ± 6 °C and - 45 ± 17 °C in the NCB group and - 46 ± 7 °C and - 32 ± 23 °C in the SCB group, respectively (both p < 0.001) with no difference in time to isolation (TTI). Procedural differences were observed for the total procedure time (84 ± 29 min in the NCB group and 65 ± 17 min in the SCB group, p = 0.003). There was a peri-procedural stroke in one patient in the NCB group. Differences in catheter design were observed that may account for the differences in temperature recordings and ice cap formation. CONCLUSIONS: Acute efficacy and TTI were similar with the NCB compared to the SCB. Measured temperatures were lower with the NCB, most likely due to differences in catheter design.

Takayasu arteritis: Prevalence and clinical presentation in Switzerland.

OBJECTIVE: Takayasu arteritis (TAK) is a rare immune-mediated vasculitis of the aorta and its branches. Aims were to calculate prevalence and incidence in Switzerland, to assess disease activity and performance of MR-Angiography (MRA). METHODS: 31 patients were recorded in a database, 27 were followed prospectively up to 3 years. Prevalence was calculated based on data of the national statistical bureau. Disease activity was defined using the revised EULAR criteria. MRA depicted stenotic changes and aortic wall enhancement. RESULTS: A disease prevalence of 14.5/1.000.000 inhabitants and an incidence of 0.3/1.000.000 per year was calculated. Aortic wall enhancement was found in 10 patients while in clinical and serological remission. EULAR criteria missed 5 patients with disease activity with isolated elevations of ESR/CRP. Arterial stenosis did not change over time in 5 cases, it improved in 2 and increased in 7. At follow-up 16 patients were treated with tocilizumab, 11/16 in monotherapy, 5 patients were treatment-free, 25/27 stayed in remission. CONCLUSION: In addition to prevalence and incidence, our data show that MRA qualifies to detect subclinical disease activity, but, on the other hand, that EULAR criteria may miss disease activity in case of isolated elevation of ESR/CRP.