Blanking Period Research Articles

Radiofrequency ablation of atrial fibrillation-50 W or 90 W?

This study sought to evaluate the short and midterm efficacy and safety of the novel very high power very short duration (vHPvSD) 90 W approach compared to HPSD 50 W for atrial fibrillation(AF) ablation as well as reconnection patterns of 90 W ablations. Consecutive patients undergoing first AF ablation with vHPvSD (90 W; predefined ablation time of 3 s for posterior wall ablation and 4 s for anterior wall ablation) were compared to patients using HPSD (50 W; ablation index-guided; AI 350 for posterior wall ablation, AI 450 for anterior wall ablation) retrospectively. A total of 84 patients (67.1 ± 9.8 years; 58% male; 47% paroxysmal AF) were included (42 with 90 W, 42 with 50 W) out of a propensity score-matched cohort. 90 W ablations revealed shorter ablation times (10.5 ± 6.7 min vs. 17.4 ± 9.9 min; p = .001). No major complication occurred. 90 W ablations revealed lower first pass PVI rates (40% vs. 62%; p = .049) and higher AF recurrences during blanking period (38% vs. 12%; p = .007). After 12 months, both ablation approaches revealed comparable midterm outcomes (62% vs. 70%; log-rank p = .452). In a multivariable Cox regression model, persistent AF (hazard ratio [HR]: 1.442, 95% confidence interval [CI]: 1.035-2.010, p = .031) and increased procedural duration (HR: 1.011, 95%CI: 1.005-1.017, p = .001) were identified as independent predictors of AF recurrence during follow-up. AF ablation using 90 W vHPvSD reveals a similar safety profile compared to 50 W ablation with shorter ablation times. However, vHPvSD ablation was associated with lower rates of first-pass isolations and increased AF recurrences during the blanking period. After 12 months, 90 W revealed comparable efficacy results to 50 W ablations in a nonrandomized, propensity-matched comparison.

Absence of atrial fibrillation in the blanking period following cryoballoon pulmonary vein isolation – does it always portend a good prognosis?

Abstract Background Cryoballoon (CB) pulmonary vein isolation (PVI) is an accepted method for ablation in patients with paroxysmal and persistent atrial fibrillation (PAF, PeAF). Freedom from AF in the blanking period (BP), conventionally defined as the first 3-months post-PVI, has been associated with the best long-term outcomes. However, the influence of antiarrhythmic drugs (AADs) during the BP on long-term outcomes is not well understood. Objective To compare long-term outcomes between patients who were and were not on an AAD prior to ablation and remained free from AF during the 3-month BP post CB PVI. Methods We enrolled consecutive AF patients undergoing CB PVI; all pts had an implantable loop recorder (ILR). No patient had any AF in the first 90 days post CB PVI. We divided the patients into three groups: (1) never had exposure to an AAD; (2) were intolerant to/failed AAD and thus were not taking an AAD at time of ablation; and (3) were on AAD at time of ablation. In the latter group, every effort was made to stop the AAD before the end of the BP. Results The cohort included 96 pts (66±10 years; 60 [63%] male; 55 [57%] PAF; CHA2DS2-VASc 2.5±1.4). There were 23 (24%) patients in group 1, 13 (14%) patients in group 2, and 60 (63%) pts in group 3. Patients in group 3 were more likely to have PeAF; AADs were stopped at a median of 36 days IQR (27, 91) in this group. Patients were followed for 1-year during which time 28 (29%) patients had recurrent AF (despite having no AF during the BP). The best outcome was seen in patients who never used an AAD; the worst outcome was seen in patients who were on an AAD at time of ablation (Figure 1). Conclusion Our data show that absence of AF during a 3-month post CB PVI BP alone does not guarantee good-long term outcome, unless the patient was never treated with an AAD. In contrast, in patients ablated while taking an AAD, recurrent AF was observed in 37% even though they were completely AF-free during the BP. Funding Acknowledgement Type of funding sources: None.

Evaluating the value of the timing of recurrence during blanking period after atrial fibrillation ablation

Abstract Introduction In the first weeks after atrial fibrillation (AF) ablation, the arrythmia may recur theoretically due to transient local inflammation and not due to treatment failure. This is defined as the blanking period, with a proposed duration of 3 months. Recently, this time period has been brought into question. The aim of this work was to evaluate the correlation between the timing of blanking recurrence and late AF recurrence. Methods This was a single-centre retrospective study including patients without structural heart disease that underwent first AF ablation and were subsequently enrolled in the post ablation structured program between 2018 and 2021. Patients were excluded if they had <6 months follow-up. Appointment with ECG and Holter monitoring was performed at 1, 3, 6 and 12 months after ablation. Results We included a total of 193 patients (56% male, mean age 63±12 years). Of these, 79% had paroxysmal AF and mean left atrial volume index was 58±18 mL/m2. During the 3-month blanking period, there were 39 (21%) recurrences, 18 (9%) of which in the first month. After blanking period, at 6 months, 25 (13%) patients had AF recurrence, 56% of which had already recurred during blanking period. AF recurrence in the 2nd and 3rd month of blanking increased the odd of recurrence at 6-month by more than 5-fold (odds ratio (OR) 8,944; CI 95% 2,817–28,400, p<0.001 and OR 5,591; 95% CI 1,173–26,651; p=0.031). On the other hand, recurrence of AF during the 1st month of blanking was not associated with increased chance of 6-month AF recurrence (OR 2,095, 95% CI 0,630–6,964, p=0.227) (figure 1). There were no significant differences in clinical variables, including LA volume, between patients with 1-month recurrence and patients without recurrences. However, patients with AF recurrence in the 2nd and 3rd month of blanking had significantly increased LA volume. Conclusion Our study suggests that patients with AF recurrence in the 2nd and 3rd month of blanking have structurally different atria and are at a significantly higher risk of post blanking AF recurrence, in contrast with patients with AF recurrence in the 1st month of blanking, thus questioning the appropriate duration of the blanking period. Funding Acknowledgement Type of funding sources: None.

Additional value of left atrium remodeling assessed by three-dimensional echocardiography for the prediction of atrial fibrillation recurrence after cryoballoon ablation

Abstract Background Atrial fibrillation (AF) is the most common cardiac arrhythmia and it is associated with a high risk of cardiovascular complications [1]. Cryoballoon ablation (CBA) has emerged as a safe and efficient therapeutic option for AF [2]. However, AF recurrence occurs in more than 25% of the patients, which leads to repeated ablations and increased rates of complications and hospitalizations [3]. Previous reports on the role of left atrial (LA) diameter and LA volume assessed by two-dimensional echocardiography (2DE) as predictors of AF recurrence after ablation have shown controversial results [4,5]. This might be explained by the fact that these methods imply geometrical assumptions of the LA remodeling, which is a three-dimensional process [6]. Purpose The purpose of this study was to evaluate the additional value of LA remodeling assessed by three-dimensional echocardiography (3DE) to predict AF recurrence after CBA. Methods Consecutive patients with paroxysmal/persistent AF undergoing CBA were prospectively included. Echocardiography was performed before CBA, according to standard recommendations. Blanking period was defined as the first three months post-ablation. The primary endpoint was AF recurrence after the blanking period. Results One hundred seventy two patients (62.2±12.2 years, 61% male) were included in the analysis. During the follow-up period of 11.7±1.6 months, fifty (29%) patients had AF recurrence after the blanking period. 3DE LA maximum volume index (LAVI) had the highest incremental predictive value for AF recurrence (HR 5.50, 95% CI 1.34–22.45, p<0.001) (Figure 1). Twenty-two percent of the AF recurrences occurred in patients with non-dilated LA diameter index and LAVI by 2DE (68 (39.5% patients)). In this category of patients, LAVI by 3DE was able to discriminate AF recurrence with a sensitivity of 90% and a specificity of 66%, for an optimal cut-off value of 30.4 ml/m2. Conclusion This study showed that LAVI assessed using 3DE had an additional predictive value for AF recurrence after CBA. Moreover, LAVI by 3DE was able to discriminate AF recurrence even in patients with non-dilated LA by M-Mode and 2DE. These findings suggest that 3DE might reflect better and earlier the asymmetric and variable nature of LA remodeling and could be a potential tool in clinical practice for an improved risk stratification and pre-ablation selection of AF patients. Funding Acknowledgement Type of funding sources: Public hospital(s). Main funding source(s): Universitair Ziekenhuis Brussel: Wetenschappelijk Fonds Willy Gepts of the UZ Brussel

Incremental value of left atrial strain to predict atrial fibrillation recurrence after cryoballoon ablation

Abstract Background Cryoballoon ablation (CBA) has emerged a one of the safest and efficient therapeutic options for atrial fibrillation (AF) [1]. However, AF recurrence rate after CBA remains as high as 25–30%, leading to increased rates of complications and repeated procedures [2]. Left atrial (LA) structural remodeling, defined as LA dilation has been proposed as a predictor of AF recurrence after CBA [2]. However, LA mechanical dysfunction might appear even before the LA enlargement and might be a more sensitive prognostic indicator of AF recurrence [3–5]. The early recognition of LA dysfunction might play a key role in identifying patients at higher risk of AF recurrence after CBA, even in patients without a dilated LA. Purpose The purpose of this study was to evaluate the additional value of LA function, assessed using speckle tracking echocardiography to predict AF recurrence after CBA. Methods Consecutive patients with paroxysmal/persistent AF undergoing CBA were prospectively included. Echocardiography was performed before CBA, according to standard recommendations. Blanking period was defined as the first three months post-ablation. The primary endpoint was AF recurrence after the blanking period. Results One hundred seventy two patients (62.2±12.2 years, 61% male) were included in the analysis. During the follow-up period of 11.7±1.6 months, 50 (29%) patients had AF recurrence. In the overall study population, peak atrial longitudinal strain (PALS) ≤17% had the highest incremental predictive value for AF recurrence (HR=9.45, 95% CI: 3.17–28.13, chi-square to improve 37% increase, p<0.001) (Figure 1). In patients with non-dilated LA (119 (69.1%) patients), AF recurrence occurred in 24 (20.2%) patients. In this category of patients, PALS ≤17% remained an independent predictor of AF recurrence (HR=5.39, 95% CI: 1.66–17.52, p=0.005). Conclusions This study showed that LA function assessed by PALS provided an additional predictive value for AF recurrence after CBA, over LA enlargement. In patients with non-dilated LA, PALS remained an independent predictor of AF recurrence. These findings emphasize the added value of LA strain, suggesting that it should be implemented in the systematic evaluation of the AF patients before CBA. Funding Acknowledgement Type of funding sources: Public hospital(s). Main funding source(s): Universitair Ziekenhuis Brussel - Wetenschappelijk Fonds Willy Geps of the UZ Brussel

High epicardial fat volume is associated with atrial fibrillation recurrences after catheter ablation

Abstract Background Pulmonary vein isolation (PVI) is the cornerstone of catheter ablation therapy for atrial fibrillation (AF). However, even with important technological improvements, AF recurrences are common in long-term follow-up. Recently, epicardial fat tissue (EFT) has been proposed as a potential AF modulator promoting and sustaining atrial arrhythmogenic milieu. Aim In this retrospective single-centre study, we sought to evaluate the association between CT-quantified EFT volume and long-term primary PVI outcome assed by means of continuous ECG monitoring with implantable loop recorders (ILR) in paroxysmal AF patients. Methods A cohort of 92 patients (median age 60.2 [IQR 51.9–64.0]; 74% male) with paroxysmal AF (a single persistent AF episode was accepted) undergoing catheter ablation targeted at PVI was analysed. Prior to CA all patients underwent cardiac CT imaging with subsequent implantation of implantable loop recorder (ILR). Radiofrequency CA ablation with electro-anatomical mapping for PVI was used in 79 patients, balloon cryoablation was used in 13 patients. Verified complete PVI was defined as procedural endpoint. EFT volume was semi-automatically segmented and quantified on contrast enhanced CT studies. AF recurrence, defined as AF burden >0.1% after the blanking period (90 days), was continuously assessed by ILR. Kaplan-Meier analysis of AF recurrence-free survival at 1-year, 2-year and 3-year follow-up periods compared patients stratified into EFT volume tertiles. Results During a median follow-up of 52.6 months [IQR 43–64], AF recurrence was detected in 58 (63%) patients, 29 (50%) of them underwent a repeat ablation. Patients in high, mid, and low total EFT volume tertiles had a median time to late AF recurrence of 154, 373, and 284 days (Fig. 1A). At a 1-year follow-up, patients in the high EFT volume tertile had the worst AF ablation outcome (p=0.023). However, this difference gradually faded-out and became non-significant at 2 and 3 years. ROC analysis revealed an EFT of 95 ml as an optimal cut-off (p=0.002) for expected arrhythmia recurrence post acutely successful PVI (Fig. 1B). Conclusion EFT volume quantification in a relatively homogenous, continuously monitored cohort of patients undergoing catheter ablation for paroxysmal AF revealed a significant association between AF recurrence at 1 year post ablation and volume of epicardial fat. These results suggest a possible role of epicardial adipose tissue as an adverse pro-fibrillatory factor. Identified EFT volume cut-offs have to be validated prospectively on a larger and balanced patient population. Funding Acknowledgement Type of funding sources: None.

Predictors of long-term atrial fibrillation recurrence after catheter ablation: non-linear analytical approach for individualized prognostic stratification

Abstract Background Recurrences are common in patients with atrial fibrillation (AF) during long-term follow-up after catheter ablation (CA) for pulmonary vein isolation (PVI). Recently, machine learning (ML) models identifying non-linear relationships among various patient parameters have been applied for prognostic stratification in different cardiac diseases. Aim This is a retrospective study aimed to determine whether ML-based models can identify non-linear relationships in individual clinical baseline characteristics and CT-quantified volumetric parameters of epicardial fat tissue (EFT) to aid in prognosing outcome of catheter ablation for PVI in patients with paroxysmal AF. Methods A cohort of 92 patients (median age 60.2 [51.9–64.0]; 74% male) with paroxysmal AF (a single persistent AF episode was accepted) undergoing catheter ablation targeting PVI was analysed. All patients underwent cardiac CT imaging and were fitted with implantable loop recorder (ILR) prior to CA. For PVI, radiofrequency CA with electro-anatomical mapping was used in 79 patients, cryoballoon ablation in 13 patients. AF recurrence, defined as AF burden >0.1% after the blanking period (90 days), was continuously assessed by ILR. Feature selection on 23 baseline parameters was performed using random forest models (XGBoostRegressor). Mean absolute Shapley values (|mSHAP| – Shapley Additive expLanations) were used to quantify the relative discriminative power of analysed parameters. Results During a follow-up of 3-years, AF recurrence was detected in 58 (63%) patients, 29 (50%) of them underwent a repeat ablation. Five most important predictors of AF recurrence during 3-year follow-up were upper epicardial fat volume, BMI, baseline AF burden, age and pericardial volume (lower segment) (Fig. 1). Upper EFT volume was twice as important for males than females (0.44 and 0.21 |mSHAP| respectively). For a patient with no AF recurrence, low age (41 years) and low upper EFT volume (13.2 ml) were the most important drivers predicting positive ablation outcome (Fig. 2A). In contrast, in a patient with AF recurrence post CA, an above-average EFT volume of 55.5 ml and a high BMI had the most significant net contribution for predicting his failed CA outcome (Fig. 2B). Conclusion Non-linear ML analysis applied to our limited cohort of patients with paroxysmal AF undergoing CA suggests: i) a significant association of high EFT volume with ILR determined AF recurrence during a 3-year follow-up; ii) potential role of such analyses for a more granular and highly individualized prediction of outcome of planned CA. However, these results need further testing, and validation in prospective trials. Funding Acknowledgement Type of funding sources: None.

Recurrence of atrial fibrillation following pulmonary vein isolation: impact of body mass index on one- and three-year outcomes

Abstract Background Cryoballoon (CB) pulmonary vein isolation (PVI) is an accepted method for ablation in patients with paroxysmal and persistent atrial fibrillation (PAF, PeAF). However, there are a paucity of data about the impact of body mass index (BMI) on one-year and longer-term outcomes following ablation. Objective To objectively understand the impact of BMI on outcomes following CB PVI. Methods We enrolled consecutive AF patients undergoing CB PVI; all patients had an implantable loop recorder (ILR), which transmitted data wirelessly daily. We assessed AF recurrences after excluding an initial 3-month post-ablation blanking period. Results The cohort included 222 pts (66±9 years; 143 [64%] male; 120 [54%] PAF; CHA2DS2-VASc 2.6±1.6). The mean BMI was 30±5. Patients were followed for 763±347 days, during which time 50% and 68% had recurrent AF 1- and 3-years post ablation. We divided the cohort based on the mean BMI into 2 groups: BMI <30 and BMI >30. Heavier patients were younger and more likely to have PeAF. Over 1-year of follow-up, patients with a BMI <30 had similar likelihood of being free of AF to patients with a BMI >30 (46% vs, 56%, p=0.0.097, Figure 1, left). However, as patients were followed for 3-years, freedom from AF was significantly higher in patients with a BMI <30 (59% vs. 81% in BMI >30, p=0.002, Figure 1, right). Conclusions Our data show that although patients had similar outcomes 1-year post-ablation, during longer-term follow-up patients with a BMI >30 had a much worse outcome. Our study uniquely offers objective (using an ILR) assessment of the impact of BMI on long-term outcomes following CB PVI (homogenous ablation strategy). These data highlight the need to identify strategies to improve outcomes in obese patients. Funding Acknowledgement Type of funding sources: None.

Safety and efficacy of catheter ablation for atrial fibrillation in the very elderly

Abstract Background The incidence and prevalence of atrial fibrillation (AF) increases with age. With an ageing general population, a 2.3-fold rise in AF prevalence is expected. Catheter ablation has emerged as an effective treatment option for rhythm control therapy. However, very elderly patients (≥80 years old) have been excluded in landmark clinical trials. Current data regarding the safety and efficacy of catheter ablation in the very elderly is therefore sparse. Purpose Due to the growing demand to manage AF in an increasingly ageing population, we investigated the safety and efficacy of catheter ablation in this particular patient population. Methods Patients with symptomatic paroxysmal, persistent and long-standing persistent AF aged ≥80 years undergoing catheter ablation, including first and re-ablation procedures in a single centre, were analysed retrospectively. Catheter ablation involved pulmonary vein isolation (PVI) using radiofrequency, cryoballoon and pulsed field ablation as energy sources. Re-ablation procedures included re-PVI and consecutive atrial tachycardia ablation including atrial lines and/or ablation of complex fractionated atrial electrograms (CFAE) in persistent AF. Endpoints included acute procedural success (complete isolation of pulmonary veins and/or non-inducibility in the case of atrial tachycardia), major complications and early arrhythmia-recurrence. Results A total of eighty-eight patients (mean age 83.1±1.9 years, mean CHA2DS2-VASc-Score 4.4±1, mean left ventricular ejection fraction 56.7±7%, direct oral anticoagulation 92.1%, vitamin-K antagonists 7.9%) were included from January 2021 to October 2021. Fifty cases (56.8%) involved PVI as an index procedure (radiofrequency 58%, n=29/50, cryoballoon 36%, n=18/50, pulsed field ablation 6%, n=3/50). Thirty-eight procedures (43.2%) involved re-ablation procedures (Re-PVI 60.5%, n=23/38, linear lesions 65.8%, n=25/38, atrial tachycardia ablation 26.3%, n=10/38 and ablation of CFAE 15.8%, n=6/38). Acute procedural success was achieved in 87/88 patients (98.9%). Major complications included stroke (n=1/88, 1.1%), pericardial tamponade (n=1/88, 1.1%) and bradycardia with subsequent pacemaker implantation (n=3/88, 3.4%). No further major complications were documented. In 13/88 patients (14.8%) early arrhythmia-recurrence occurred (38.5%, n=5/13 after the index procedure and 61.5%, n=8/13 after re-ablation) during the 90-day blanking period. Conclusions Catheter ablation for atrial fibrillation in the very elderly shows favourable acute success and low complication rates. Long term success of catheter ablation and superiority to rate control in this patient population is unknown and requires investigation in the future. Funding Acknowledgement Type of funding sources: None.

Lower recurrence rates of atrial fibrillation in early compared to late ablation – a Danish nationwide study

Abstract Introduction Guidelines recommend antiarrhythmic drugs (AAD) before ablation for atrial fibrillation (AF). However, recently published randomized clinical trials have demonstrated that ablation is more effective in maintaining sinus rhythm compared to AAD as first line therapy. Therefore, data pertaining the impact of early ablation on AF recurrence in large, unselected cohorts is highly warranted. Purpose To examine clinically relevant AF recurrence after ablation by time from AF diagnosis to ablation. Method Using Danish nationwide registries, all Danish patients above 18 years who underwent first-time AF ablation from January1st 2010 to December31st 2018 were identified and included at the date of ablation. The patients were categorized by time from diagnosis with AF to ablation. Recurrent AF was defined using a composite endpoint comprising claimed prescriptions of AAD, hospital admissions due to AF, re-ablation, or electrical cardioversions. The cumulative incidence of recurrent AF by time from diagnosis to ablation at 1-year follow-up after a blanking period of 90 days, was estimated using the Aalen-Johansen estimator, taking death as a competing risk into account. The relative rates of recurrent AF by time from diagnosis to ablation were examined using Cox models adjusted for sex, age, procedure-year, heart failure, ischemic heart disease, chronic obstructive pulmonary disease, chronic kidney disease, hypertension, and diabetes. Results The study cohort consisted of 8,098 patients. Median age [IQR] increased from 60 [52 to 66] in the early ablation group (AF ablation within 1 year after diagnosis) to 64 [57 to 70] in the late ablation group (ablation at least 3 years after diagnosis). The number of patients with a CHA2DS2-VASc score of 2 or more increased from 44% in the early ablation group to 51% in the late ablation group. Use of amiodarone remained stable, while use of Class IC anti-arrhythmic medication increased by time from diagnosis to ablation. Figure 1 shows the 1-year cumulative incidence of recurrent AF, hazard ratios (HR), and 95% confidence intervals (95% CI) stratified by time from diagnosis to ablation in years and depict that the risk of recurrent AF increased incrementally and significantly by time from diagnosis to ablation compared to the early ablation group. Figure 2 shows the 1-year cumulative incidence of recurrent AF, hazard ratios (HR), and 95% confidence intervals (CI 95%) stratified by time from diagnosis to ablation in months and depict that very early ablation (within 6 months) is associated with less recurrent AF. Conclusion In this large nationwide study examining recurrent AF post ablation, recurrence rates of AF increased incrementally according to time from AF diagnosis to AF ablation. Early ablation could potentially provide substantial benefits and improve outcomes after ablation, indicating ablation as first-line therapy might be more ideal. Funding Acknowledgement Type of funding sources: None.

Efficacy of cryoballoon ablation for atrial fibrillation in a geriatric population

Abstract Background Cryoballoon pulmonary vein isolation (cryoPVI) is well-established for paroxysmal atrial fibrillation (AF) but its value in persistent AF is less clear. In particular, its efficacy in cardiogeriatric patients (≥75 years) is unknown. Age represents an important modifier of AF progression and is a risk-factor for AF recurrence. Methods We conducted a prospective, single-center study to analyze efficacy and safety of cryoPVI in cardiogeriatric patients stratified according to AF entity. Maximum follow-up was 24 months. Efficacy endpoint was symptomatic AF relapse after 90-day blanking period. Results We included 668 patients. Of these 218 were ≥75 years old. Paroxysmal AF was present in 400 and persistent AF in 268 patients. By means of cox-regression analysis we found age as the only independent factor influencing AF recurrence in the overall cohort (P=0.034). This effect was carried by patients with persistent AF (P=0.006). At 24 months, the recurrence rate was highest in patients with persistent AF and age ≥75 years (57%; P=0.0004). Conclusion Cardiogeriatric patients with persistent AF undergoing cryoPVI had higher rates of AF recurrence compared to elderly patients with paroxysmal AF or younger patients. Against this background we assume, that pulmonary-vein dependent AF may be less frequently encountered among patients ≥75 years with persistent AF. Funding Acknowledgement Type of funding sources: None.

Cryoballoon ablation of atrial fibrillation in octogenarians: one year results from the Cryo Global Registry

Abstract Background A few studies have demonstrated the safety and efficacy of cryoballoon ablation (CBA) in elderly patients (≥75 years old) with atrial fibrillation (AF). However, global utilization and outcomes of CBA in the octogenarian population (≥80 years old) have not been reported. Purpose To evaluate the efficacy and safety of CBA of AF in patients ≥80 years old. Methods The Cryo Global Registry (NCT02752737) is an ongoing, prospective, multicenter registry. In this analysis, 1674 patients with paroxysmal or persistent AF were included in 37 global centers who treated at least one octogenarian with CBA. Analysis cohorts were defined as patients ≥80 and patients <80 years old (control). To address safety issues of CBA in octogenarians, serious procedure-related complications were assessed. Utilizing Kaplan-Meier estimates, 12-month freedom from a ≥30sec AF/atrial flutter (AFL)/atrial tachycardia (AT) recurrence following a 90-day blanking period was evaluated. Results The average age of the octogenarians (n=101) was 82±2 years vs 62±10 years in the control group (n=1573). More females were found in the octogenarian population (51.5% vs 35.7%, p<0.01). The ≥80-year-old cohort had lower BMI (26±4 kg/m2 vs 27±5 kg/m2), higher CHA2DS2-VASc-Scores (4.2±1.3 vs 2.0±1.5), and a higher proportion of heart failure (all p<0.01). The patient cohort ≥80 years was similar compared to the control group regarding the AF history (70.3% vs 74.4% paroxysmal AF), years diagnosed with AF (2.9±4.9 vs 3.2±4.8), and left atrial diameter (43±8 mm vs 42±8 mm) (all p>0.05). Success rates of acute pulmonary vein isolation did not differ between the groups (95.0% vs 96.2%, p=0.59). No differences were observed between ≥80- (5.9%) and <80-year-old patients (3.5%) with respect to serious adverse events (p=0.26). Rhythm monitoring, comprising of Holter and 12-lead ECG, was performed on average 3.1±3.1 times in the elder population and 3.2±3.1 times in the control group through 12 months (p=0.84). Efficacy at 12 months was not different between groups, resulting in 80.6% (95% CI: 71.0–87.3%) freedom from AF/AFL/AT recurrence at 12 months in the octogenarians compared to 78.9% (95% CI: 76.7–80.9%) in the control group (p=0.70). Fewer patients were prescribed AADs at 12 months (32.2%, 23.7%) compared to discharge (47.8%, 49.1%), octogenarians and control, respectively. Further, octogenarians were less likely to receive a repeat ablation 3.3% (95% CI: 1.1–9.7%) in comparison to the control cohort 9.2% (95% CI: 7.8–10.8%) (p=0.052). The 12-month Kaplan-Meier estimate of freedom from cardiovascular-related hospitalization was 81.1% (95% CI: 71.7–87.7%) in the octogenarian and 84.8% (95% CI: 82.9–86.6%) in the control group, respectively (p=0.21). Conclusion Cryoballoon ablation for the treatment of AF is a safe procedure in octogenarians, with efficacy and complication rates comparable to younger patients. Funding Acknowledgement Type of funding sources: Private company. Main funding source(s): Medtronic, Inc.

EP News: Clinical

Marrouche et al (JAMA 2022;327:2296, PMID 35727277) investigated targeting atrial fibrosis detected on magnetic resonance imaging (MRI) in reducing atrial arrhythmia recurrence in persistent AF. A total of 843 patients with persistent AF were randomized to pulmonary vein isolation (PVI) plus MRI-guided atrial fibrosis ablation (421 patients) or PVI alone (422 patients). The primary end point was time to first atrial arrhythmia recurrence after a 90-day blanking period postablation. There was no significant difference in atrial arrhythmia recurrence between groups (fibrosis-guided ablation plus PVI patients, 175 [43.0%] vs PVI-only patients 188 [46.1%]; hazard ratio [HR] 0.95; P = .63).

Neural correlates of lateral modulation and perceptual filling-in in center-surround radial sinusoidal gratings: an fMRI study

We investigated lateral modulation effects with functional magnetic resonance imaging. We presented radial sinusoidal gratings in random sequence: a scotoma grating with two arc-shaped blank regions (scotomata) in the periphery, one in the left and one in the right visual field, a center grating containing pattern only in the scotoma regions, and a full-field grating where the pattern occupied the whole screen. On each trial, one of the three gratings flickered in counterphase for 10 s, followed by a blank period. Observers were instructed to perform a fixation task and report whether filling-in was experienced during the scotoma condition. The results showed that the blood-oxygen-level-dependent signal was reduced in areas corresponding to the scotoma regions in the full-field compared to the center condition in V1 to V3 areas, indicating a lateral inhibition effect when the surround was added to the center pattern. The univariate analysis results showed no difference between the filling-in and no-filling-in trials. However, multivariate pattern analysis results showed that classifiers trained on activation pattern in V1 to V3 could differentiate between filling-in and no-filling-in trials, suggesting that the neural activation pattern in visual cortex correlated with the subjective percept.

Catheter ablation and thoracoscopic ablation in long persistent atrial fibrillation with large left atrium.

BackgroundPulmonary vein antrum isolation (PVAI) is the cornerstone of atrial fibrillation (AF) ablation, but the clinical outcomes of PVAI are unsatisfactory in patients with persistent AF and a large left atrium (LA).ObjectivesWe investigated the clinical outcomes following radiofrequency ablation (RFCA), cryoballoon ablation (CBA), and thoracoscopic maze in patients with persistent AF and a large LA.MethodsWe included patients with consecutive persistent AF who had a large LA (LA diameter >50 mm) and underwent RFCA, CBA, or thoracoscopic maze surgery. In the RFCA group, additional linear ablation was performed at the physician’s discretion. The endpoint was 12 months without recurrence of an atrial arrhythmia, including AF, atrial flutter, and atrial tachycardia, following a 90-day blanking period.ResultsWe recruited 89 persistent AF patients with a large LA who underwent RFCA (n = 32), CBA (n = 38), or the thoracoscopic maze procedure (n = 19). During the 12-month follow-up, 48 (53.9%) cases of AF recurrence were observed. There was no prognostic difference between groups (50.0% in RFCA vs. 52.6% in CBA vs. 63.2% in thoracoscopic maze, all P > 0.05). Early recurrence during the blanking period was a significant predictor of late recurrence for RFCA and CBA, but not for the thoracoscopic maze.ConclusionIn persistent AF patients with a large LA, we did not find a prognostic difference RFCA, CBA, or a thoracoscopic maze procedure in recurrence of atrial arrhythmia. Early recurrence predicted late recurrence in catheter ablation, but not in thoracoscopic maze.

Prognostic Implications of Left Atrial Spontaneous Echo Contrast with Catheter Ablation of Nonvalvular Atrial Fibrillation Patients with Left Atrial Dilation.

Background: Left atrial spontaneous echo contrast (LASEC) can be detected by transesophageal echocardiography (TEE) before the catheter ablation of atrial fibrillation (AF), especially in patients with left atrial (LA) dilation. Whether LASEC has prognostic value in predicting the procedure outcomes in patients with an enlarged atrium is unknown. The prognostic implications of LASEC with the catheter ablation of AF patients with LA dilation will be evaluated in this study. Methods: AF patients scheduled to undergo catheter ablation in Ruijin Hospital, Shanghai, China, between January 2018 and June 2020 were screened for this prospective study. All patients underwent TEE before the procedure. Patients with a left atrial diameter (LAD; 45 mm ≤ LAD < 50 mm) and left atrial volume (LAV ≥ 120 mL) were enrolled in this study. The endpoint was AF/atrial tachycardia (AT) recurrence-free survival following a 3-month blanking period after the catheter ablation. All patients were followed up for 18 months. Results: This study included 123 AF patients, who were divided into the LASEC (n = 73) and no LASEC (n = 50) groups. Baseline patient characteristics were similar in the two groups. At the end of 18 months of follow-up, AF/AT recurrence-free survival was achieved in 33 (45.2%) and 34 (68.0%) patients in the LASEC and no LASEC groups, respectively (p = 0.013). In survival analysis, the LASEC group was also associated with a poor outcome of catheter ablation (log-rank test, p = 0.011; Cox regression, p = 0.015, HR = 2.058, 95%CI = 1.151–3.679). Meanwhile, during the follow-up AF/AT recurrence was observed in 30 (57.7%) and 15 (71.4%) cases in the mild and severe SEC groups, respectively. Ischemic stroke occurred in two patients in the LASEC group. Conclusions: LASEC could be a predictor of the recurrence of AF/AT after catheter ablation in AF patients with LA dilation. The higher the degree of LASEC, the worse the prognosis.

Hydrocarbon emission control of an adsorptive catalytic gasoline particulate filter during cold-start period of the gasoline engine

In order to reduce HC emission of the gasoline engine during cold start to meet increasingly stringent emission standards, an adsorptive catalytic gasoline particulate filter (A-CGPF) is proposed and a mathematical model of the A-CGPF is established. Then, HC adsorption performance, conversion performance and abatement performance of the A-CGPF coated with different catalyst under different inlet HC concentration are investigated during cold start. The results show that inlet HC concentration, exhaust temperature has great influence on the adsorption process, while mass flow rate has little influence; penetration time decreases with the increase of inlet hydrocarbon concentration. In addition, the catalytic conversion performance order is MCA > Rh–Pd > CeO2 > PCZ > Pd under adiabatic condition, their corresponding light-off time is 10s, 34s, 56.4s, 57s and 57.2s, respectively. Compared with the A-CGPF coated with adsorbent or catalyst, adsorption duration time of the A-CGPF coated with composite adsorptive catalysts is shortened, and its catalytic oxidation stage is advanced; the cumulative HC emission in the first 40s of the cold start phase is significantly reduced and the HC removal rate is increased; the HC removal performance order is MMC > MRP > MC > MP > MPCZ, and the HC removal blank period due to interaction effect between adsorption and catalytic oxidation can be properly shortened. Moreover, the inlet HC concentration fluctuation results in the deterioration of carrier temperature rise, prolongs the removal blank period, and decreases the HC removal rate at the initial stage of cold start. Compound rare earth oxide MCA has better HC abatement performance than other catalysts. This work provides reference for hydrocarbon abatement performance enhancement of a GDI engine and design of coupled after-treatment system.

Feasibility and safety of laser balloon pulmonary vein isolation in patients with prior left atrial appendage occlusion device implantation.

With the increasing adoption of left atrial appendage occlusion (LAAO) procedures and the eligibility of patients for pulmonary vein isolation (PVI) post device placement, we examined the feasibility and safety of laser balloon (LB) for PVIin patients with prior LAAO. We retrospectively examined consecutive patients with paroxysmal or persistent, drug-resistant atrial fibrillation(AF) who underwent LB PVI, after Watchman FLX device implantation at Rush University Medical Center between January 2020 and December 2021. Seven patients (four persistent and three paroxysmal) with a mean age of 64 ± 11 years, predominantly male sex (86%), were included in the study. Two (29%) patients had prior cryoablation PVI with recurrence of AF. The mean CHA2 DS2 VASc is 2.6 ± 0.5 and the mean HAS-BLED score is 3.4 ± 0.8. The mean follow-up duration was 10 ± 7 months. The mean duration between Watchman FLX device implantation and LB PVI was 592 days. Acute first pass left pulmonary vein (PV) isolation was achieved in 100% of the procedures. There were no periprocedural complications such as death, pericardial tamponade or effusion, phrenic nerve injury, PV stenosis, device perforation or embolization, or worsening peri-device leak in any of the patients. None of the patients had AF recurrence after the blanking period. LB PVI was safe and effective with 100% acute isolation of left-sided veins in patients with prior LAAO device.

Early recurrence after cryoballoon versus radiofrequency ablation for paroxysmal atrial fibrillation: mechanism and implication in long-term outcome

BackgroundEarly recurrence (ER) after catheter ablation for atrial fibrillation (AF) has been considered as a common phenomenon but its mechanism and implication in long-term outcome has not been fully elucidated. We aimed to clarify the relation between post-ablation inflammation and ER after cryoballoon ablation (CBA) or radio-frequency ablation (RFA) and evaluate the clinical significance of ER.MethodsA total of 154 patients with paroxysmal AF undergoing ablation were consecutively recruited, including 90 patients undergoing RFA (RF group) and 64 patients undergoing CBA (CB group). Myocardial injury and inflammation biomarkers were analyzed before and 6 h, 24 h and 48 h after ablation. Acute early recurrence (AER), non-acute early recurrence (NAER) and late recurrence (LR) was defined as recurrence of atrial tachyarrhythmia during 0–3, 4–90 days and beyond a 90-day blanking period after ablation.ResultsCardiac troponin I was significantly higher in CB group while C reactive protein (CRP) and Ratio Neutrophil/Lymphocyte were more elevated in RF group. Higher CRP level after RFA was significantly associated with AER in RF group and lower CRP level after CBA was predictive of AER in CB group. In addition, average cryoablation duration was positively correlated with CRP level after CB group. Cox regression revealed that NAER and left atrial diameter were associated with LR in RF group, while AER and NAER were predictive of LR after CBA.ConclusionsPost-ablation inflammation was greater in RFA than in CBA. Excessive inflammatory response may be an important factor of AER after RFA. AER after CBA was related with lower inflammation and predictive of LR. Further investigations are still warranted to address on these findings.

Left atrial hypertension invasively measured during pulmonary vein isolation predicts atrial fibrillation recurrence.

The clinical role of left atrial hypertension (LAH) in patients with atrial fibrillation (AF) and its role as predictor in those undergoing pulmonary vein (PV) isolation is still unknown. The aim of the present study was to analyse the prevalence of LAH in patients with nonvalvular AF and preserved left ventricular ejection fraction who underwent PV isolation and its implication for AF catheter ablation. Consecutive patients with drug resistant AF who underwent PV isolation at San Maurizio Regional Hospital of Bolzano (Italy) as index procedure were retrospectively included in this analysis. Left atrial hypertension was defined as the LA mean pressure ≥15 mmHg. A total of 98 consecutive patients (71 males, 72%; mean age 60.3±8.4 years) were included in the analysis. Eleven patients (11%) underwent radiofrequency ablation and 87 (89%) cryoballoon ablation. The mean LA pressure was 11.7±5.5 mmHg; LAH occurred in 24 (24.5%) patients. At a mean follow-up of 14.6±7.1 months (median 14 months), the success rate without antiarrhythmic therapy was 71.4% (70/98; considering the blanking period). Older age, LA volume and LAH were significantly associated with early AF recurrence during the blanking period. However, only LAH independently remained a significant predictor of late AF recurrence (HR 3.02, 1.36-6.72, P=0.007). Left atrial hypertension was found in 24% of patients undergoing PV isolation and was found to be significantly related to both early and late AF recurrences.