The effect of left atrial remodeling after cryoballoon ablation and radiofrequency ablation for paroxysmal atrial fibrillation

BackgroundCryoballoon ablation (CBA) and radiofrequency ablation (RFA) are the most common procedures used to treat refractory atrial fibrillation (AF) and are performed through pulmonary vein isolation (PVI). Studies have shown that CBA can approximately match the therapeutic effects of RFA against AF. However, few studies have investigated the difference between CBA and RFA of the effects on left atrial remodeling for paroxysmal AF.ObjectiveAtrial remodeling is considered pivotal to the occurrence and development of AF, therefore we sought to assess the influence of atrial remodeling in patients with paroxysmal AF after CBA and RFA in this study.MethodsIn this nonrandomized retrospective observational study, we enrolled 328 consecutive patients who underwent CBA or RFA for refractory paroxysmal AF in May 2014 to May 2017 in our hospital. After propensity score matching, 96 patients were included in the CBA group, and 96 were included in the RFA group. Patients were asked to undergo a 12‐lead electrocardiogram, a 24‐h Holter monitor, and an echocardiogram and to provide their clinical history and symptoms at 6 months and 1, 2, and 3 years postprocedurally. Electrical remodeling of the left atrium was assessed by P wave dispersion (Pdis); structural remodeling was assessed by the left atrium diameter (LAD) and left atrial volume index (LAVI) during scheduled visits.ResultsAs of January 2020, compared with baseline, at 1 year, 2 years, and 3 years after ablation, the average changes in Pdis (∆Pdis), LAD (∆LAD), and LAVI (∆LAVI) were significant in both the CBA and RFA groups. Six months after ablation, ∆Pdis, ∆LAD, and ∆LAVI were greater in the CBA group than in the RFA group. There was no significant difference between the two groups in AF/flutter recurrence, but the AF/flutter‐free survival time of CBA group may be longer than RFA group after 2 years after ablation. A higher ∆Pdis, ∆LAD, or ∆LAVI at 1 year after ablation may increase AF/flutter‐free survival.ConclusionsAlthough CBA and RFA are both effective in left atrial electrical and structural reverse‐remodeling in paroxysmal AF, CBA may outperform RFA for both purposes 6 months after ablation. However, during long‐term follow‐up, there was no significant intergroup difference.     

心房颤动冷冻消融方法的应用进展

肺静脉隔离是心房颤动（房颤）导管消融的基石,冷冻球囊是专门为肺静脉解剖结构设计的工具,应用冷冻球囊 导管进行肺静脉隔离（PVI）的有效性和安全性获得了临床研究证实,国内外指南都已将冷冻球囊消融作为房颤消融 PVI的标准疗法。冷冻球囊消融具有持久肺静脉隔离、安全性高、操作简便、患者感受好、学习曲线短等优势,因此, 近10年在临床得以迅速普及应用。随着技术的不断创新和临床研究的深入,冷冻球囊消融疗法也在不断拓展。文 章就房颤冷冻球囊消融方法及应用进展进行论述。     

冷冻球囊消融与射频消融对阵发性心房颤动患者心房重构的影响

目的:比较冷冻球囊消融(CBA)与射频消融(RFA)对阵发性心房颤动(房颤)患者心房重构的影响.方法:本研究选取在2014年5月-2017年5月于郑州大学第一附属医院因阵发性房颤行CBA或RFA治疗的患者.所有患者均于术前、术后半年、1年、2年和3年时行12导联心电图或24 h动态心电图和超声心动图检查.左心房电重构通...     

Predictive value of HMGB1 for atrial fibrillation recurrence after cryoballoon ablation in paroxysmal atrial fibrillation patients

BackgroundCryoballoon ablation (CBA) is recommended for patients with symptomatic drug refractory paroxysmal atrial fibrillation (pAF). However, substantial atrial fibrillation (AF) recurrence is common during follow‐up. Searching for a potential biomarker representing both myocardial injury and inflammation to identify patients at high risk of AF recurrence after CBA is very meaningful for postoperative management of AF patients.HypothesisTo evaluate the clinical efficacy of high‐mobility group box 1 (HMGB1) protein released from the left atrium to predict AF recurrence in pAF patients after CBA at 1‐year follow‐up.MethodsWe included 72 pAF patients who underwent CBA. To determine the expression levels of HMGB1, left atrial blood samples were collected from the patients before CBA and after the procedure through the transseptal sheath. Patients were followed up for AF recurrence for 1 year.ResultsA total of 19 patients of the 72 experienced AF recurrence. The level of postoperative HMGB1 (HMGB1post) was higher in the AF recurrence group than in the AF non recurrence group (p = .03). However, no differences were noted in the levels of other biomarkers such as preoperative high‐sensitivity C‐reactive protein (hs‐CRP), postoperativehs‐CRP, and preoperative HMGB1 between the two groups. Multiple logistic regression analysis revealed that a higher level of serum HMGB1post was associated with AF recurrence (odds ratio: 5.29 [1.17–23.92], p = .04). Receiver operating characteristic analysis revealed that HMGB1post had a moderate predictive power for AF recurrence (area under the curve: 0.68; sensitivity: 72%; and specificity: 68%). The 1‐year AF‐free survival was significantly lower in patients with a high HMGB1post level than in those with a low HMGB1post level (hazard ratio: 3.81 [1.49–9.75], p = .005).ConclusionIn pAF patients who under went CBA, the level of HMGB1 after CBA was associated with AF recurrence and demonstrated a moderate predictive power. Thus, we offer a potential biomarker to identify pAF patients at high risk of AF recurrence.     

Prevalence and predictive factors of left atrial tachycardia occurring after second‐generation cryoballoon ablation of atrial fibrillation

1 Introduction

Assess the prevalence and predictors of left atrial tachycardia (LAT) after cryoballoon ablation of pulmonary veins.

2 Methods and results

Patients who underwent catheter ablation of pulmonary veins with a second‐generation cryoballoon for symptomatic paroxysmal (151 of 270, 56%) or persistent (119 of 270, 44%) atrial fibrillation were entered in a single‐center prospective registry. Patients who experienced postcryoballoon LAT (pcryo‐LAT) were selected on the basis of 12‐lead ECG characteristics. Left atrial origin was confirmed during conventional EP study and electroanatomical activation mapping, and patients were treated by RF catheter ablation. Pcryo‐LAT was observed in 15 (5.6%) of 270 patients and was attributed to a reentrant mechanism in 11 patients (73%). The other four cases of pcryo‐LAT were due to focal atrial tachycardia associated with reconnection of one pulmonary vein. In comparison with patients who remained in sinus rhythm, LA area (HR = 1.09; CI 1.01, 1.2; P = 0.02), LVEF (HR = 0.94; CI 0.90, 0.97; P < 0.001), and LVEF <50% (HR = 8.5; CI 3.1, 23.6; P < 0.001) were predictors of pcryo‐LAT. After multivariate Cox analysis, only left ventricular ejection fraction < 50% remained predictive of pcryo‐LAT, (HR = 7.8, CI 2.3 26.7, P = 0.002). With a mean survival of 23 months, 73% of patients who experienced pcryo‐LAT were in sinus rhythm versus 78% of patients without pcryo‐LAT (log rank P = 0.85).

3 Conclusion

The prevalence of pcryo‐LAT in patients with atrial fibrillation is low. Left ventricular ejection fraction < 50% is associated with an increased risk of pcryo‐LAT. When treated by RF catheter ablation, the presence of pcryo‐LAT is not a predictive factor of subsequent recurrence of atrial fibrillation during follow‐up.     

Sex‐specific efficacy and safety of cryoballoon versus radiofrequency ablation for atrial fibrillation: A systematic review and meta‐analysis

Background: Atrial fibrillation (AF) is a growing healthcare burden, for which pulmonary vein isolation (PVI) using cryoballoon (CB) or radiofrequency (RF) represent attractive therapies. Women are at higher risk of recurrence after AF ablation and present a specific complications profile. Therefore, a systematic catheter‐specific assessment of pulmonary vein isolation is urgently needed in women. Objective: Systematically assessing the sex‐specific efficacy/safety of CB vs RF ablation. Methods: We performed a structured database search of the scientific literature for randomized controlled trials (RCTs) and observational prospective studies (OPS) comparing CB and RF ablation efficacy at 1 year. We investigated the reporting of sex‐specific analyses and assessed the comparative sex‐specific efficacy, safety and procedural characteristics of CB vs RF using random‐effect meta‐regression accounting for the proportion of enrolled women. Results: Twenty‐three studies were included (18 OPS and 5 RCTs) for a total of 13 509 patients. Sex‐specific outcomes by ablation device were reported in two and sex‐specific regression in four studies, none of which took the ablation device into account. Meta‐regression accounting for the proportion of enrolled women showed no significant difference in outcomes between RF or CB. Conclusion: The sex‐specific reporting in trials comparing CB to RF is extremely low. A quantitative meta‐regression using the percentage of enrolled women as sex‐specific indicator did not show any difference between CB and RF but acknowledging the low percentage of enrolled women and the lack of sex‐specific data, further research including patient‐level data is urgently needed to draw more definitive conclusions.     

Radiofrequency and cryoballoon ablation improve cognitive function in patients with atrial fibrillation

Atrial fibrillation is considered to be the most common arrhythmia in the clinic, and it gradually increases with age. In recent years, there has been increasing evidence that atrial fibrillation may exacerbate the progression of cognitive dysfunction. The current guidelines recommend ablation for drug-refractory atrial fibrillation.We aimed to prospectively analyze changes in cognitive function in patients with atrial fibrillation following treatment using different ablation methods.A total of 139 patients, with non-valvular atrial fibrillation, were included in the study. The patients were divided into the drug therapy (n = 41) and catheter ablation (n = 98) groups, with the catheter ablation group further subdivided into radiofrequency ablation (n = 68) and cryoballoon (CY) ablation (n = 30). We evaluated cognitive function at baseline, 3- and 12-months follow-up using the Telephone Interview for Cognitive Status-modified (TICS-m) test, then analyzed differences in cognitive function between the drug therapy and catheter ablation groups, to reveal the effect of the different ablation methods.We observed a significantly higher TICS-m score (39.56 ± 3.198) in the catheter ablation group at 12-month follow-up (P < .001), than the drug treatment group was. Additionally, we found no statistically significant differences in TICS-m scores between the radiofrequency ablation and CY groups at 3- and 12-month postoperatively (P > .05), although the two subgroups showed statistically significant cognitive function (P < .001).Overall, these findings indicated that radiofrequency and CY ablation improve cognitive function in patients with atrial fibrillation.     

The future of atrial fibrillation therapy

Today management of atrial fibrillation (AF) centers on restoration and maintenance of normal sinus rhythm or control of the ventricular rate response to AF. Current guidelines state that rhythm and rate control strategies should be considered therapeutically equivalent, but recognize that no "one size fits all," an approach consistent with growing recognition of the heterogeneity of AF. As data from the Sotalol Amiodarone Atrial Fibrillation Efficacy Trial clearly demonstrate, conventional antiarrhythmics have a role in highly symptomatic AF accompanied by decreased quality of life. However, for many AF patients such drugs lack efficacy, have potentially serious side effects, and are poorly tolerated. In parallel with the development of more effective and safer antiarrhythmics, nontraditional approaches to prevention and treatment of AF are being explored. Treatments not considered "antiarrhythmic" that may prevent or forestall AF include aggressive antihypertensive therapy with angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, and some, but not all, beta-blockers and calcium channel antagonists, especially when used as adjunctive therapy. Other approaches include statins, steroids, and fish oil to reduce atrial fibrosis and inflammation, and pacemakers to prevent bradycardia-mediated AF and as a pacing preventive strategy in selected patients. Ablative techniques with potential to cure AF are gaining popularity, but are not yet simple, straightforward, and risk-free procedures. In the future, treatment of AF will progress beyond today's focus on AF as a purely electrocardiographic disease toward a patient and context-specific management strategy involving multiple treatment modalities.     

A multicenter prospective randomized study comparing the incidence of periprocedural cerebral embolisms caused by catheter ablation of atrial fibrillation between cryoballoon and radiofrequency ablation (Embo‐Abl study): Study design

BackgroundAlthough catheter ablation (CA) has become a standard therapeutic approach to atrial fibrillation (AF), it imposes a low but relevant risk of thromboembolic complications of around 0.5%–1%, including ischemic strokes, and has an additional risk of clinically silent cerebral embolisms (SCEs) of 10%–40%. Both cryoballoon (CB) and radiofrequency (RF) ablation are routinely used clinically worldwide, yet there are few prospective data comparing the incidence of cerebral embolism after CA of AF between CB and RF ablation.MethodsThe aim of the Embo‐Abl study will be to compare the incidence of cerebral embolisms on 3 T diffusion‐weighted image magnetic resonance imaging (MRI) after CA of AF between CB and RF ablation in patients with AF in a prospective, multicenter, open‐label, controlled, randomized fashion. The primary endpoint of the Embo‐Abl study will be the occurrence of MRI‐detected SCE 1–3 days after CA. The patients will be registered and randomly assigned to either the CB or RF ablation group in a 1:1 ratio. The study cohort will include 230 patients with AF from a multicenter in Japan.ResultsThe results of this study are currently under investigation.ConclusionThe Embo‐Abl study will be the first to compare the incidence of periprocedural cerebral embolisms caused by CA of AF between CB and RF ablation in a prospective, multicenter, randomized, controlled fashion.     

Effect of catheter ablation on progression of paroxysmal atrial fibrillation

Ablation and Progression of Atrial Fibrillation. Objective: The objective was to determine the effect of radiofrequency catheter ablation (RFA) on progression of paroxysmal atrial fibrillation (AF). Background: Progression to persistent AF may occur in up to 50% of patients with paroxysmal AF receiving pharmacological therapy. Hypertension, age, prior transient ischemic event, chronic obstructive pulmonary disease, and heart failure (HATCH score) have been identified as independent risk factors for progression of AF. Methods: RFA was performed in 504 patients (mean age: 58 ± 10 years) to eliminate paroxysmal AF. A repeat RFA procedure was performed in 193 patients (38%). Clinical variables predictive of outcome and their relation to progression of AF after RFA were assessed using multivariate analysis. Results: At a mean follow‐up of 27 ± 12 months after RFA, 434/504 patients (86%) were in sinus rhythm; 49/504 patients (9.5%) continued to have paroxysmal AF; and 14 (3%) were in atrial flutter. Among the 504 patients, 7 (1.5%) progressed to persistent AF. In patients with recurrent AF after RFA, paroxysmal AF progressed to persistent AF in 7/56 (13%, P < 0.001). The progression rate of AF was 0.6% per year after RFA (P < 0.001 compared to 9% per year reported in pharmacologically treated patients). Age >75 years, duration of AF >10 years and diabetes were independent predictors of progression to persistent AF. The HATCH score was not significantly different between patients with paroxysmal AF who did and did not progress to persistent AF (0.7 ± 0.8 vs 1.0 ± 0.5, P = 0.3). Conclusions: Compared to a historical control group of pharmacologically treated patients with paroxysmal AF, RFA appears to reduce the rate of progression of paroxysmal AF to persistent AF. Age, duration of AF, and diabetes are independent risk factors for progression to persistent AF after RFA. (J Cardiovasc Electrophysiol, Vol. 23, pp. 9‐14, January 2012)     

Demographic profile of patients undergoing catheter ablation of atrial fibrillation

Demographic Profile of Patients Undergoing AF Ablation. Background: Catheter ablation is a widely accepted treatment for drug refractory atrial fibrillation (AF). The purpose of our study was to examine secular trends in the demographic profile of patients undergoing AF ablation. Methods and Results: Data for 792 patients who underwent catheter ablation for AF at Johns Hopkins Hospital between years 2001 and 2009 were systematically reviewed. There has been a steady increase in total number of procedures and repeat procedures. The majority of patients undergoing AF ablation at our institution are men (76.6%). Females accounted for 36.0% of patients in 2001 versus 19.6% in 2009. A total of 93.3% of patients undergoing AF ablation were Caucasian. The mean age of patients has increased over time (52 years in 2001 to 60 years in 2009, P = 0.015) and the number of antiarrhythmic drugs (AADs) used prior to first ablation has decreased (2.3 to 1.2, P = 0.009). In addition, the mean duration of AF prior to first referral has decreased (7.8 years in 2001 vs 4.2 years in 2009). Conclusion: There is a significant gender and racial disparity in patients undergoing AF ablation favoring Caucasian men that warrants further investigation. We also observed a significant increase in age of patients, decrease in number of AADs, and increase in number of repeat procedures. These results are important when interpreting outcomes of AF ablation and designing future trials. (J Cardiovasc Electrophysiol, Vol. 22, pp. 994‐998, September 2011)