Benefit of atrial fibrillation ablation on symptoms and quality of life does not differ between patients with paroxysmal and persistent atrial fibrillation

Funding Acknowledgements

Type of funding sources: None.

Background

Indications for atrial fibrillation (AF) ablation in current ESC and ACC/HRS guidelines are different for paroxysmal and persistent AF patients. Although previous research has established that the AF recurrence rate after AF ablation is lower in paroxysmal AF patients, there is little data on differences in post-ablation improvement of quality of life (QoL) and AF-related symptoms.

Purpose

This study aimed to determine whether QoL and symptom improvement differ between patients with paroxysmal and persistent AF after AF ablation.

Methods

From December 2017 to June 2020, patients undergoing first AF ablation at a medical center were included in a prospective registry. Circumferential pulmonary vein isolation (PVI) was performed using radiofrequency ablation with a contact force-sensing catheter. Patient reported outcomes were assessed at baseline, 4 months follow-up, and 1 year follow-up using the Toronto Atrial Fibrillation Severity Scale (AFSS). The AFSS was used to quantify global well-being (scale 1-10), patient-perceived AF burden (scale 3-30), and AF symptom severity (scale 0-35). AF symptom severity was based on 7 questions (scale 0-5) leading to a 0-35 scale. AF recurrence was defined as any documented episode of AF or atrial flutter after a blanking period of 3 months.

Results

The study population consisted of 306 AF patients (66% paroxysmal AF, 68% male, mean age 64±8 years). AF recurrence during 1 year follow-up occurred in 29% of paroxysmal AF patients and in 42% of persistent AF patients (p=0.021). At baseline, patient perceived AF burden was lower in paroxysmal AF patients than in persistent AF patients (18.4±3.7 vs. 20.2±5.0, p=0.001), whereas symptom severity (10.6±6.5 vs. 9.9±6.7, p=0.384) and global well-being (7.1±1.5 vs. 7.3±1.4, p=0.327) were similar. Paroxysmal AF patients reported more palpitations (2.4±1.3 vs. 1.6±1.5, p<0.001) and less shortness of breath during physical activity (1.9±1.6 vs. 2.3±1.7, p=0.048) than patients with persistent AF.

Significant improvements in global well-being (0.5±1.7, p<0.001), symptom severity (3.8±7.2, p<0.001), and patient-perceived AF burden (7.2±7.5, p<0.001) were found in the entire study cohort between baseline and 1 year follow-up, without differences between paroxysmal and persistent patients (Figure).

Conclusion

Although persistent AF patients have a higher chance of recurrent AF after AF ablation, symptom severity and QoL improve equally in paroxysmal and persistent AF patients. These results suggest that different recommendations for AF ablation to improve symptoms in paroxysmal and persistent AF patients may not be justified.

Predictive value of ten risk scores for outcomes of atrial fibrillation patients undergoing radiofrequency pulmonary vein isolation

Funding Acknowledgements

Type of funding sources: None.

Background/Introduction:

A significant number of patients experience recurrent atrial fibrillation (AF) after ablation. Predicting who will or will not benefit from AF ablation is challenging. Although various risk scores have been designed to predict outcomes after AF ablation, comparative data are sparse and external risk score validation is often lacking.

Purpose

In this study, we aimed to compare ten previously described risk scores with regard to their predictive value for post-ablation AF recurrence and procedural complications.

Methods

A total of 482 AF patients (37% non-paroxysmal AF, 66% male, mean age 62 ± 9 years) undergoing initial radiofrequency pulmonary vein isolation (RF-PVI) were included in the present analysis. Prior to ablation, all patients underwent both transthoracic echocardiography and either cardiac computed tomography imaging or cardiac magnetic resonance imaging. The following risk scores were calculated for each patient: APPLE, ATLAS, BASE-AF2, CAAP-AF, CHADS2, CHA2DS2-VASc, DR-FLASH, HATCH, LAGO and MB-LATER. The predictive performance of the risk scores for AF recurrence and complications were assessed separately by receiver operating characteristic (ROC) curves.

Results

Median follow-up was 16 (12-31) months. AF recurrence after the 90-day blanking period was observed in 199 patients (41%), occurring after a median of 183 (124-360) days after ablation. Overall procedural adverse event rate was 6%. The HATCH score was the only score without predictive value for recurrent AF after ablation (area under curve [AUC] 0.545). All other investigated scores demonstrated statistically significant but poor predictive value for recurrent AF after ablation (AUC 0.553-0.669). CHA2DS2-VASc and CAAP-AF were the only risk scores with predictive value for procedural complications (AUC 0.616, p = 0.043; AUC 0.615, p = 0.044; respectively). ROC curve analyses of the studied risk scores for the prediction of AF recurrence and complications are shown in Figure.

Conclusion

Currently available risk scores perform poorly in predicting outcomes after RF-PVI. These data suggest that the utility of these scores for clinical decision-making is limited. Abstract Figure. ROC curve analyses of risk scores

666Impact of local left atrial wall thickness on the incidence of acute pulmonary vein reconnection after ablation index-guided ablation

Background/Introduction

Pulmonary vein reconnection is considered a major determinant of atrial fibrillation (AF) recurrence after pulmonary vein isolation (PVI). Ablation Index (AI)-guided ablation allows for the creation of ablation lesions of consistent depth and may reduce the incidence of pulmonary vein reconnection after PVI. However, anatomical and imaging studies have demonstrated an important inter- and intra-patient variability of left atrial wall thickness, which can result in non-transmural ablation lesion formation in thicker segments.

Purpose

The present study aimed to investigate the impact of local left atrial wall thickness on the incidence of acute pulmonary vein reconnection after AI-guided AF ablation.

Methods

Consecutive AF patients who underwent cardiac computed tomography (CT) imaging prior to AI-guided ablation between December 2017 and September 2019 were studied. AI targets were 500 for anterior/roof and 380 for posterior/inferior segments with a maximum interlesion distance of 6 mm. Occurrence of acute pulmonary vein reconnection after initial PVI was assessed after a 30-minute waiting period. Ablation procedures were analysed offline to determine minimum AI, force-time integral, contact force, ablation duration, power, impedance drop and maximum interlesion distance for each segment according to a 16-segment model. Pulmonary vein antrum wall thickness was assessed for each segment on reconstructed CT images based on patient-specific thresholds in Hounsfield Units, using a previously described method.

Results

Seventy patients (63% paroxysmal AF, 67% male, mean age 63 ± 8 years) who underwent preprocedural CT imaging and AI-guided AF ablation were studied. Acute reconnection (AR) occurred in 27/1152 segments (2%, 15 anterior/roof, 12 posterior/inferior) in 17/70 (24%) patients. Anterior/roof segments were thicker than posterior/inferior segments (1.48 [1.23-1.80] vs. 1.13 [1.00-1.30] mm; p < 0.01). Reconnected segments were characterised by a greater local atrial wall thickness, both in anterior/roof (1.83 [1.60-2.00] vs. 1.47 [1.20-1.80] mm; p < 0.01) and posterior/inferior (1.38 [1.25-1.50] vs. 1.13 [1.00-1.27] mm; p < 0.01) segments (Figure 1). Minimum AI, force-time integral, contact force, ablation duration, power, impedance drop and maximum interlesion distance were not associated with acute pulmonary vein reconnection.

Conclusion

Local atrial wall thickness is associated with acute pulmonary vein reconnection after AI-guided PVI. Individualised AI targets based on local wall thickness may be of use to create transmural ablation lesions and prevent pulmonary vein reconnection after PVI.

Abstract Figure. Impact of wall thickness on reconnection

P984Residual gaps in the ablation line and requirement for carina ablation during contact force-guided radiofrequency pulmonary vein isolation: determinants and prognostic implications

Background

Pulmonary vein isolation (PVI) is not always achieved after initial encircling of the pulmonary veins (PVs). Additional touch-up lesions are frequently required to close residual gaps, which may occur both in the initial ablation line and on the intervenous carina.

Purpose

We aimed to identify determinants and prognostic implications of residual gaps during index radiofrequency PVI.

Methods

Two hundred fourteen AF (atrial fibrillation) patients (57% paroxysmal, 61% male, mean age 62±9 years) undergoing contact force-guided PVI were studied. Residual gaps after initial encircling of the PVs were targeted for additional ablation and were classified as either gap ablation in the initial WACA (wide-area circumferential ablation) circle or carina ablation, depending on the site of earliest activation. After a waiting period of at least 30 minutes, persistence of PVI was tested through administration of 9–18 mg intravenous adenosine. Pre-procedural cardiac computed tomography imaging was used to assess left atrial and PV anatomy. Carina width was defined as the distance between ipsilateral superior and inferior PV ostia. Ablation procedures were analyzed to define the perimeter of the WACA circle.

Results

One hundred thirty-three patients (62%) required additional ablation lesions beyond the initial WACA circles to achieve complete PVI. Gap ablation was required in the left WACA circle in 34 patients (16%) and in the right WACA circle in 49 patients (23%). Left and right carina ablation were required in 50 (23%) and 83 (39%) patients, respectively. Multivariate analyses identified carina width and perimeter of the WACA circle as independent predictors of requirement for ipsilateral carina ablation, whereas paroxysmal AF and the perimeter of the WACA circle were associated with requirement of gap ablation in the initial WACA circle. Recurrence of atrial tachyarrhythmias was documented in 73 patients (34%) at 12 months follow-up. Kaplan–Meier survival analyses demonstrated a significantly higher rate of recurrence in patients with one or more residual gaps in the ablation line (43% vs. 30%, p=0.019, figure A), whereas no significant difference between patients with and without requirement of carina ablation was found (38% and 29%, respectively; p=0.111, figure B).

Kaplan-Meier survival analyses

Conclusion

Residual gaps in the initial WACA circle were associated with increased AF recurrence rate after PVI, whereas residual gaps on the intervenous carina had no statistically significant impact on AF recurrence. Consequently, gaps occurring in the ablation line and gaps on the intervenous carina may represent different mechanisms and may have different prognostic implications.

European survey on efficacy and safety of duty-cycled radiofrequency ablation for atrial fibrillation

AIMS

Duty-cycled radiofrequency ablation (RFA) has been used for atrial fibrillation (AF) for around 5 years, but large-scale data are scarce. The purpose of this survey was to report the outcome of the technique.

METHODS AND RESULTS

A survey was conducted among 20 centres from seven European countries including 2748 patients (2128 with paroxysmal and 620 with persistent AF). In paroxysmal AF an overall success rate of 82% [median 80%, interquartile range (IQR) 74-90%], a first procedure success rate of 72% [median 74% (IQR 59-83%)], and a success of antiarrhythmic medication of 59% [median 60% (IQR 39-72%)] was reported. In persistent AF, success rates were significantly lower with 70% [median 74% (IQR 60-92%)]; P = 0.05) as well as the first procedure success rate of 58% [median 55% (IQR 47-81%)]; P = 0.001). The overall success rate was similar among higher and lower volume centres and were not dependent on the duration of experience with duty-cycled RFA (r = -0.08, P = 0.72). Complications were observed in 108 (3.9%) patients, including 31 (1.1%) with symptomatic transient ischaemic attack or stroke, which had the same incidence in paroxysmal and persistent AF (1.1 vs. 1.1%) and was unrelated to the case load (r = 0.24, P = 0.15), bridging anticoagulation to low molecular heparin, routine administration of heparin over the long sheath, whether a transoesophageal echocardiogram was performed in every patient or not and average procedure times.

CONCLUSION

Duty-cycled RFA has a self-reported success and complication rate similar to conventional RFA. After technical modifications a prospective registry with controlled data monitoring should be conducted to assess outcome.

The left bundle branch block revised with novel imaging modalities

Left bundle branch block (LBBB) is related to abnormal cardiac conduction and mechanical asynchrony and is associated with hypertension and coronary artery disease. Improved evaluation of left ventricular (LV) mechanical asynchrony is needed, because of the increasing number of patients with LBBB and heart failure. In this paper, we describe tissue Doppler imaging (TDI), strain (rate) imaging and tissue tracking in LBBB patients. A variety of patterns of mechanical activation can be observed in LBBB patients. A recent development, referred to as tissue synchronisation imaging, colour codes TDI time-to-peak systolic velocities of segments and displays mechanical asynchrony. Furthermore, real-time 3D echocardiography provides new regional information about mechanical asynchrony. Contained in an LV model and projected on a bull's eye plot, this modality helps to display the spatial distribution of mechanical asynchrony. Finally, segmental time-to-peak circumferential strain curves, produced by cardiac magnetic resonance imaging, provide additional quantification of LV mechanical asynchrony. Effects of LBBB on regional and global cardiac function are impressive, myocardial involvement seems to play a role and with the help of these novel imaging modalities, new insights continue to develop.

Distribution of renal lesions in idiopathic systemic vasculitis: A three-dimensional analysis of 87 glomeruli

Extracapillary proliferation and fibrinoid necrosis are the main diagnostic glomerular lesions in renal biopsy specimens of patients with idiopathic systemic vasculitis. Neither the incidence nor the correlation between extracapillary proliferation and fibrinoid necrosis in renal biopsy specimens from patients with systemic vasculitis has been systematically evaluated. By means of a three-dimensional analysis, we made a topographic reconstruction of the distribution of extracapillary proliferation and fibrinoid necrosis in affected glomeruli and tested different biopsy-processing protocols to optimize histopathologic analysis in clinical practice. Paraffin blocks of renal biopsy specimens from six patients diagnosed with systemic vasculitis were completely and serially sectioned in 2-microm thick sections and stained with the Gomori trichrome method. Glomeruli were scored per section for the presence of fibrinoid necrosis and extracapillary proliferation. Subsequently, a three-dimensional reconstruction was obtained for 87 glomeruli. In only one glomerulus did fibrinoid necrosis occur without extracapillary proliferation; in 51%, a combination of the two lesions was found; in 22%, extracapillary proliferation occurred in the absence of fibrinoid necrosis; and 26% did not show either lesion. Using the standard protocol from our department (ie, evaluation of 20 consecutive sections in various stainings), the chance of finding extracapillary proliferation was 100% and that of finding fibrinoid necrosis was 73%. If 5 sections stained with the Gomori trichrome were added, the latter percentage increased to 86%. Using skip-serial sections, even better results (87% to 92%) were obtained, with four skips as the best option (92%). In conclusion, our finding that fibrinoid necrosis rarely occurs in the absence of extracapillary proliferation may imply that both lesions are etiologically related. In addition, our observations indicate that the incidence of fibrinoid necrosis may be underestimated in clinical practice, depending on the number of sections evaluated.