Safety and efficacy of persistent atrial fibrillation ablation using the second-generation cryoballoon

Global Research Progress on Radiofrequency Ablation in Cardiology

Radiofrequency ablation (RFA) has become a cornerstone in treating cardiac arrhythmias, offering a minimally invasive approach to managing conditions such as atrial fibrillation, ventricular tachycardia, and other rhythm disorders. The historical evolution of RFA, from its early inception to its current state, underscores the technological advancements that have significantly enhanced its efficacy and safety. Global trends indicate a steady increase in the adoption of RFA, with notable research contributions from North America, Europe, and Asia. Comparative studies reveal outcome variability driven by differences in patient populations, procedural techniques, and healthcare infrastructures. Despite its success, RFA faces challenges, including complications related to the procedure, patient selection, and long-term efficacy. Emerging technologies, such as integrating artificial intelligence and enhanced imaging modalities, hold promise for overcoming these barriers and further refining the procedure. Gaps in current research are identified, particularly in understanding the long-term outcomes of RFA and its application in complex arrhythmias. The critical role of RFA in modern cardiology is emphasized, along with the potential for future innovations that could expand its therapeutic utility. This synthesis of the latest evidence provides valuable insights for optimizing the use of RFA in managing cardiac arrhythmias.

Comprehensive analysis of recurrence factors in cryoballoon AF ablation: integrating clinical, biomarkers, and echocardiographic parameters

Atrial fibrillation (AF) poses substantial challenges in cardiovascular diseases, impacting patient health and economic burdens. Understanding the mechanical effects of AF on the left atrium (LA) and assessing the influence of treatment modalities on LA functions are critical. This study aims to assess the efficacy of echocardiographic and biochemical parameters in predicting AF recurrence following second generation cryoballoon ablation (CB-2). Ninety-two patients with symptomatic AF, treated with CB-2 at Istanbul University-Cerrahpaşa, Faculty of Medicine, Department of Cardiology, were prospectively examined from January 2021 to July 2023. The study endeavors to develop a predictive model for AF recurrence, investigating the relationship between echocardiographic measurements and serum biomarkers with recurrence. The follow-up duration for echocardiographic assessments and biochemical analyses was systematically documented. The study revealed a significant enhancement in LA mechanical functions during echocardiographic follow-ups three months post-procedure. Specifically, LA strain parameters emerged as significant predictors of recurrence (LAsr: 95%CI 1.004-1.246, p = 0.047; LAsct: 95%CI 1.040-1.750, p = 0.024). Biochemical analyses demonstrated a correlation between elevated PRO-BNP levels and an increased risk of recurrence (95%CI 1.000-1.003, p = 0.012). Moreover, specific biomarkers such as MYBPHL, which demonstrated increased levels post-procedure, were deemed indicative of atrial damage, suggesting potential additional atrial substrate modification beyond PVI. Consequently, improvements in LA function post-cryoballoon ablation and biochemical markers have surfaced as potential indicators for predicting AF recurrence. This study elucidates the effectiveness of CB-2 in treating AF and its impact on LA functions. Notably, LA strain measurements and PRO-BNP levels have emerged as reliable indicators for predicting recurrence. Beyond clinical implications, our research establishes a foundation for a deeper understanding of the role of CB-2 in AF management and factors associated with recurrence.

Effects of Inflammatory Cell Death Caused by Catheter Ablation on Atrial Fibrillation

Atrial fibrillation (AF) poses a serious healthcare burden on society due to its high morbidity and the resulting serious complications such as thrombosis and heart failure. The principle of catheter ablation is to achieve electrical isolation by linear destruction of cardiac tissue, which makes AF a curable disease. Currently, catheter ablation does not have a high long-term success rate. The current academic consensus is that inflammation and fibrosis are central mechanisms in the progression of AF. However, artificially caused inflammatory cell death by catheter ablation may have a significant impact on structural and electrical remodeling, which may affect the long-term prognosis. This review first focused on the inflammatory response induced by apoptosis, necrosis, necroptosis, pyroptosis, ferroptosis and their interaction with arrhythmia. Then, we compared the differences in cell death induced by radiofrequency ablation, cryoballoon ablation and pulsed-field ablation. Finally, we discussed the structural and electrical remodeling caused by inflammation and the association between inflammation and the recurrence of AF after catheter ablation. Collectively, pulsed-field ablation will be a revolutionary innovation with faster, safer, better tissue selectivity and less inflammatory response induced by apoptosis-dominated cell death.

Serum periostin as a predictor of early recurrence of atrial fibrillation after catheter ablation

Catheter ablation is an effective method of rhythm therapy for atrial fibrillation (AF). AF recurrence is a common problem after catheter ablation. The aim of this study was to investigate influence factors of early recurrence after catheter ablation for AF. One hundred and three consecutive patients with AF were enrolled and underwent catheter ablation. Venous blood (Marked as A) was collected before ablation and left atrial blood (Marked as B) was collected after successful atrial septal puncture to detect serum periostin. After 3 months of follow-up, statistical analysis was made based on the recurrence of AF. 27 (26.2%) patients had a recurrence of atrial arrhythmia after catheter ablation. Patients with recurrent atrial arrhythmia had a larger left atrial volume (162.31 ± 47.76 vs. 141.98 ± 41.64,p = 0.039), and higher serum periostin levels (periostin A. 99.71 ± 16.475 vs. 90.36 ± 13.63, p = 0.005; periostin B. 103.95 ± 13.09 vs. 94.46 ± 15.85, p = 0.006) compared with the non-recurrent group. The numbers of patients with left atrial low-voltage areas (LVAs) were more in the recurrence group (p < 0.001). Left atrial volume, serum periostin and left atrial LVAs were included in univariate and multivariate COX regression analysis. It showed that left atrial LVAs (HR3.81; 95% CI 1.54 to 9.44; p = 0.004) and serum periostin A (HR1.07; 95% CI 1.02 to1.13; p = 0.008) were the independent predictors of AF recurrence. The cut-off value of serum periostin A was 87.95 ng/ ml (AUC, 0.681; sensitivity 88.9% and specificity 53.9%). Kaplan-Meier survival curve showed that the recurrence rate of AF was higher in patients with left atrial LVAs and higher serum periostin. The venous serum periostin level and left atrial LVAs were independent predictors of early recurrence of AF after catheter ablation.

Catheter Ablation for Atrial Fibrillation in Patients ≤30 Years of Age

Pulmonary vein (PV) automaticity is an established trigger for paroxysmal atrial fibrillation (PAF), making PV isolation (PVI) the cornerstone of catheter ablation. However, data on triggers for atrial fibrillation (AF) and catheter ablation strategy in very young patients aged <30 years are sparse. A total of 51 young patients (mean age 24.0 ± 4.2 years, 78.4% men) with drug-refractory PAF underwent electrophysiology (EP) study and ablation at 5 EP centers. None of the patients had structural heart disease or family history of AF. EP study induced supraventricular tachycardia (SVT) in 12 patients (n = 12, 23.5%): concealed accessory pathway mediated orthodromic atrioventricular reentrant tachycardia in 3 patients, typical atrioventricular nodal reentrant tachycardia in 6 patients, left superior PV tachycardia in 1 patient, left atrial appendage tachycardia in 1 patient, and typical atrial flutter in 1 patient. In patients with induced SVTs, SVT ablation without PVI was performed as an index procedure, except for the patient with atrial flutter who received cavotricuspid isthmus ablation in addition to PVI. Remaining patients underwent radiofrequency (n = 15, 29.4%) or second-generation cryoballoon-based PVI (n = 24, 47%). There were no major complications related to ablation procedures. Follow-up was based on outpatient visits including 24-hour Holter-electrocardiogram at 3, 6, and 12 months after ablation, or additional Holter-electrocardiogram was ordered in case of symptoms suggesting recurrence. Recurrence was defined as any atrial tachyarrhythmia (ATA) episode >30 seconds after a 3-month blanking period. A total of 2 patients with atrioventricular nodal reentrant tachycardia, 1 with left atrial appendage tachycardia, experienced AF recurrence within the first 3 months and received PVI. After the 3-month blanking period, during a median follow-up of 17.0 ± 10.1 months, 44 of 51 patients (86.2%) were free of ATA recurrence. In the PVI group, 33 of 39 patients (84.6%) experienced no ATA recurrence. In conclusion, SVT substrate is identified in around a quarter of young adult patients with history of AF, and targeted ablation without PVI may be sufficient in the majority of these patients. PVI is needed in the majority and is safe and effective in this population.

Cryoballoon Ablation for Persistent and Paroxysmal Atrial Fibrillation: Procedural Differences and Results from the Spanish Registry (RECABA)

Introduction: Cryoballoon ablation (CBA) has become a standard treatment for paroxysmal atrial fibrillation (PaAF) but limited data is available for outcomes in patients with persistent atrial fibrillation (PeAF). Methods: We analyzed the first 944 patients included in the Spanish Prospective Multi-center Observation Post-market Registry to compare characteristics and outcomes of patients undergoing CBA for PeAF versus PaAF. Results: A total of 944 patients (57.8 ± 10.4 years; 70.1% male) with AF (27.9% persistent) were prospectively included from 25 centers. PeAF patients were more likely to have structural heart disease (67.7 vs. 11.4%; p < 0.001) and left atrium dilation (72.6 vs. 43.3%; p < 0.001). CBA of PeAF was less likely to be performed under general anesthesia (10.7 vs. 22.2%; p < 0.001), with an arterial line (32.2 vs. 44.6%; p < 0.001) and assisted transeptal puncture (11.9 vs. 17.9%; p = 0.025). During an application, PeAF patients had a longer time to −30 °C (35.91 ± 14.20 vs. 34.93 ± 12.87 s; p = 0.021) and a colder balloon nadir temperature during vein isolation (−35.04 ± 9.58 vs. −33.61 ± 10.32 °C; p = 0.004), but received fewer bonus freeze applications (30.7 vs. 41.1%; p < 0.001). There were no differences in acute pulmonary vein isolation and procedure-related complications. Overall, 76.7% of patients were free from AF recurrences at 15-month follow-up (78.9% in PaAF vs. 70.9% in PeAF; p = 0.09). Conclusions: Patients with PeAF have a more diseased substrate, and CBA procedures performed in such patients were more simplified, although longer/colder freeze applications were often applied. The acute efficacy/safety profile of CBA was similar between PaAF and PeAF patients, but long-term results were better in PaAF patients.

Early arrhythmia recurrence after cryoballoon ablation in atrial fibrillation: a systematic review and meta-analysis

BACKGROUND

Early arrhythmia recurrence within the three-month blanking period is a common event that historically has been attributed to reversible phenomena. While its' mechanistic links remain obscure, accumulating evidence support the argument of shortening the blanking period. We aimed to elucidate the association between early and late arrhythmia recurrence after atrial fibrillation cryoablation.

METHODS

The MEDLINE database, ClinicalTrials.gov, medRxiv and Cochrane Library were searched for studies evaluating early and late arrhythmia recurrence rates in patients undergoing cryoablation for AF. Data were pooled by meta-analysis using a random-effects model. The primary endpoint was late arrhythmia recurrence.

RESULTS

Early arrhythmia recurrence was found predictive of decreased arrhythmia-free survival after evaluating 3975 patients with paroxysmal or persistent atrial fibrillation who underwent cryoablation (OR: 5.31; 95% CI: 3.75-7.51). This pattern remained unchanged after sub-analyzing atrial fibrillation type (paroxysmal; OR: 7.16; 95% CI: 4.40-11.65 and persistent; OR: 7.63; 95% CI: 3.62-16.07) as well as cryoablation catheter generation (first generation; OR: 5.15, 95% CI: 2.39-11.11 and advanced generation; OR: 5.83, 95% CI: 3.68-9.23). Studies permitting anti-arrhythmic drug utilization during blanking period or examining early recurrence as a secondary outcome were found to be a significant source of statistical heterogeneity.

CONCLUSION

Our findings suggest that early arrhythmia recurrence is predictive of late outcomes after cryoablation for atrial fibrillation. Identifying which patients deserve earlier re-intervention is an open research avenue. This article is protected by copyright. All rights reserved.

Results and Predictive Factors After One Cryoablation for Persistent Atrial Fibrillation

Cryoballoon pulmonary vein isolation (PVI) for persistent atrial fibrillation (AF) ablation is an increasingly used strategy. We aimed to determine the results and predictors of arrhythmia recurrence after a single procedure of cryoballoon PVI for patients with persistent and long-standing persistent AF. We included all consecutive patients who underwent cryoballoon PVI for the treatment of persistent symptomatic drug-refractory AF since 2012. All patients were prospectively followed to detect the recurrence of atrial tachyarrhythmia (ATa). Predictors of recurrence were assessed. Cryoballoon PVI was performed on 399 patients with persistent AF, among whom 52 (13%) had long-standing persistent AF. Patients with long-standing persistent AF had a significantly larger left atrium than those with persistent AF. A 28-mm cryoballoon was used for 322 patients (93%). In total, 359 patients (90%) completed the 12-month follow-up visit and the median follow-up was 24 months (interquartile range 43 to 13). The 2-year probability of freedom from ATa recurrence was 51% for persistent AF and 27% for long-standing persistent AF. Long-standing persistent AF and left atrial area/volume were independent predictors of ATa recurrence. Ten patients (2.5%) experienced phrenic nerve palsy, 1 tamponade (0.25%), 2 stroke (0.5%), 2 pericardial effusions (0.5%), and 5 vascular complications (1.25%). In conclusion, 2-year ATa-free survival rates were 51 and 27% for persistent and long-standing persistent AF patients, respectively. Complications were rare. Long-standing persistent AF and left-atrial area/volume were predictors of recurrence.

Comparison of Amiodarone and Propafenone in Blanking Period after Radiofrequency Catheter Ablation in Patients with Atrial Fibrillation: A Propensity Score-Matched Study

Background

Amiodarone and propafenone are commonly used to maintain sinus rhythm in patients with atrial fibrillation (AF). However, it is not known which one is better in reducing early recurrence (ER) during the blanking period (the first three months after catheter ablation).

Objective

To compare the efficacy and safety of amiodarone and propafenone in reducing ER during the blanking period after radiofrequency catheter ablation (RFCA) in AF patients.

Materials and Methods

A total of 694 patients who underwent their first RFCA between May 2014 and May 2018 were enrolled in this retrospective study. Subsequently, 202 patients were excluded according to the exclusion criteria. The remaining 492 patients were divided into two groups based on the choice of antiarrhythmic drugs (AADs) (amiodarone or propafenone) in the blanking period. The primary outcomes were incidence of ER and AAD-associated adverse effects during the blanking period after RFCA. Propensity score matching (PSM) analyses were used to compare the outcomes of the two groups while controlling for confounders.

Results

Among the 492 patients who took AADs in the blanking period (187 amiodarone and 305 propafenone), PSM selected 135 unique pairs of patients with similar characteristics. Amiodarone was associated with a lower ER incidence rate (23.7% versus 48.9%, p < 0.001) and a similar rate of AAD-associated adverse effects (2.1% versus 1.5%, p = 0.652). Treatment with amiodarone in the blanking period was significantly associated with a lower ER incidence rate compared to treatment with propafenone (HR = 0.416, 95% CI 0.272–0.637, p < 0.001).

Conclusions

Compared with propafenone, amiodarone was associated with a lower ER incidence rate, and they had similar rates of AAD-associated adverse effects. Treatment with amiodarone in the blanking period was shown to be more effective in reducing ER than propafenone.

Rapid pulmonary vein isolation utilizing the third-generation laserballoon - The PhoeniX registry

Background

Balloon-based ablation systems for pulmonary vein isolation (PVI) are providing procedural safety and efficacy as well as favourable clinical outcome. Although second-generation laser balloon (LB2) based PVI has been shown safety and efficacy relatively long procedural duration was a strong limitation. The third-generation laser balloon (LB3) offers and automized ablation for rapid PVI. We determined safety, efficacy and procedural characteristics of this new promising ablation system.

Methods and results

A total of 15 consecutive patients were prospectively enrolled. All patients underwent PVI using the LB3. A total 59/59 PVs (100%) were successfully isolated. Procedural data was compared to the last 15 consecutive patients treated by the LB2. The median procedure time significantly declined from LB2 (91 (86, 105) min) to LB3 (77 (68, 87) min), p < 0.001. Similarly, the median left atrial dwelling time significantly decreased from LB2 (72 (62, 84) min) to LB3 (45 (38, 52) min), p < 0.0001. The total laser time decreased from LB2 (1920 (1765, 2193) sec) to LB3 (1077 (896, 1165) sec), p < 0.00001. A pure single shot PVI was performed in 18/59 PVs (31%). For major adverse events no differences were detected between the groups (LB2 1/15 (6.7%) and LB3 1/15 (6.7%), p = 0.999).

Conclusion

The LB3 was safe and effective for PVI. Procedure time, LA dwelling time and total laser time significantly decreased compared to LB2.

A risk stratification scoring system for new-onset atrial fibrillation after ischemic stroke: A National cohort study

Atrial fibrillation (AF) is a major independent risk factor of stroke and anticoagulation therapy is needed in patients with AF after ischemic stroke. However, the detection rate of AF is low after ischemic stroke. Developing a prediction model for newly diagnosed AF after ischemic stroke will help to assess the subclinical AF.We identified 98,103 patients with diabetes mellitus (DM) and 261,893 patients without DM, who were not AF history and admitted for newly ischemic stroke from the National Health Insurance Research Database in Taiwan. The prediction model for 3-year incidence of AF after ischemic stroke was derived from multivariate logistic regression and also the accuracy rate of the prediction model was compared with CHA2DS2-VASC and CHADS2 scores as a reference.Four thousand nine hundred seventy six patients in the DM cohort and 16,127 patients in the non-DM cohort developed AF during 3 years of follow-up. The variables in the point-based prediction model for non-DM patients (range: -3-28), included age, heart failure, coronary artery disease, gout, obstructive pulmonary disease, hypertension, female, and statin use, while those for DM patients (range: -2-30) included age, heart failure, coronary artery disease, chronic kidney disease, hypertension, obstructive pulmonary disease, and statin use. Compared to the CHADS2 and CHA2DS2-VASc scoring systems, this scoring system was better at predicting 3-year risk of AF after ischemic stroke in both cohorts.This model might be useful in evaluating the benefit of insertable cardiac monitor implantation and anticoagulation agents in individual patients after ischemic stroke.

Safety and Efficacy of Cryoballoon Ablation for the Treatment of Atrial Fibrillation in Diabetic Patients

Background

Cryoballoon based catheter ablation (CB-CA) is an established therapy for treatment of symptomatic atrial fibrillation (AF). However, data about AF ablation using the CB in the diabetic population is sparse. The aim of this single center retrospective study is to evaluate the safety and efficacy of CB ablation in patients with diabetes mellitus (DM) as compared to patients without DM.

Methods and results

Between July 2015 and December 2017, 397 consecutive patients underwent CB-CA for AF. Forty-eight consecutive patients with DM (DM group, study group) were compared with propensity score-matched patients without DM (n=48, control group). All patients underwent pulmonary vein isolation (PVI) using the second-generation CB (CB2). The mean age in the DM group was 66.9±9.5 years and 69.5±8.8 in the non-DM group (p=0.18). During a follow-up of 12.7±5.1 months, single procedure success rate for the DM and the non-DM group was 68.7% and 70.8%, respectively (p=0.82). The most common complication was transient phrenic nerve palsy (4 DM group vs. 0 non-DM group, p=0.04). No severe complication such as procedure related deaths, atrio-esophageal fistula or cerebrovascular embolic events occurred.

Conclusions

Our data strengthen the value of CB2 based ablation for the treatment of AF as an effective and safe procedure in DM patients, with similar success rates when compared with a non-DM population.

Relationship between psychological factors and atrial fibrillation: A meta-analysis and systematic review

BACKGROUND

Although several studies have investigated the role of psychological factors in atrial fibrillation (AF), the results are still under debate. Therefore, we performed a meta-analysis to examine the relationship between psychological factors and the risk of incident AF.

METHODS

We systematically searched the PubMed and EMBASE databases from inception to December 2019 to identify eligible studies. The hazard ratios (HRs) with 95% confidence intervals (CIs) were pooled by using a random-effects model.

RESULTS

A total of 11 cohort studies were included in this meta-analysis. There were 5, 2, 4, and 5 studies examining the association of anxiety, anger, depression, and psychological stress with AF, respectively. In the pooled analysis by a random-effects model, anxiety (HR = 1.10, 95%CI 0.97-1.24; P = .14), anger (HR = 1.08, 95%CI 0.95-1.23; P = .21), depression (HR = 1.15, 95%CI 0.98-1.35; P = .08), and work stress (HR = 1.14, 95%CI 0.98-1.34; P = .09) were not associated with the risk of AF. These results were not changed when we re-performed the analysis using a fixed-effects model.

CONCLUSIONS

Based on current evidence, no associations were observed for anger, anxiety, and work stress with the risk of AF.

Second-Generation Visually Guided Laser Balloon Ablation System for Pulmonary Vein Isolation: Learning Curve, Safety and Efficacy - The MERLIN Registry

BACKGROUND

Radiofrequency (RF)-based pulmonary vein isolation (PVI) results in a favorable clinical outcome, although its complexity demands a long learning curve. Balloon-based systems have been developed to possibly solve these limitations. The 2nd-generation laser balloon (LB2) offers optimized features for improved tissue contact and visibility. We determined the safety, efficacy and learning curve of the LB2 for PVI.

METHODS AND RESULTS

A total of 45 consecutive patients (89% persistent AF) were prospectively enrolled and divided into 3 groups (T1, T2, T3) of n=15 patients per group. All patients underwent PVI by 2 operators using the LB2. The operators were experienced in RF and cryothermal procedures, but not in laser ablations. A total of 174/177 PVs (98%) were successfully isolated. The median procedure time significantly declined from 132 (114, 158) to 119 (102, 127) and 91 (86, 105) min in T1-3, respectively (P=0.0009). Similarly, the median fluoroscopy time significantly decreased from T1 to T3 (22 (17, 27) vs. 21 (16, 24) vs. 13 (10, 17) min, respectively, P=0.045). Adverse events occurred in 6.7%, with a trend towards a lower complication rate with increasing experience.

CONCLUSIONS

The LB2 was safe and effective for PVI, even for operators without any previous experience in laser balloon-based PVI. Procedure time, left atrial dwelling time and fluoroscopy time decreased after a learning curve of 15 cases.

Acute Procedural Complications of Cryoballoon Ablation: A Comprehensive Review

Catheter ablation is increasingly performed for treatment of atrial fibrillation (AF). Balloon based procedures have been developed aiming at safer, easier and more effective treatment as compared to point to point ablation. In the present review article, we aimed to discuss acute procedural complications of cryoballoon ablation.

Efficacy and Safety of Cryoballoon Ablation in Patients With Heart Failure and Reduced Left Ventricular Ejection Fraction - A Multicenter Study

BACKGROUND

Second-generation cryoballoon (CB2)-based pulmonary vein isolation (PVI) has demonstrated encouraging results in the treatment of atrial fibrillation (AF). This study sought to assess data on the safety, efficacy and clinical success of CB2-based PVI in patients with heart failure (HF) and reduced ejection fraction (HFrEF).

METHODS AND RESULTS

CB2-based PVI was performed in 551 consecutive patients in 3 highly experienced EP centers. Patients with HF and LVEF ≤40% were included (HFrEF group, n=50/551, 9.1%). Data were compared with propensity score-matched patients without HF and preserved left ventricular EF (LVEF) (n=50, control group). The median LVEF was HFrEF: 37% (35, 40) and control: 55% (55, 55), P<0.0001. Major periprocedural complications were registered in 4/50 (8%, HFrEF group) and 3/50 (6%, control group), P=0.695. The 12-month freedom from AF recurrence was 73.1% (95% confidence interval (CI): 61-88, HFrEF group) and 72.6% (95% CI: 61-87, control group), P=0.25. NYHA class decreased from 2.4±0.8 (baseline) to 1.7±0.8 at 12-month follow-up (P<0.0001). LVEF improved from a median of 37% (35, 40) prior to ablation to a median of 55% (40, 55), P<0.0001.

CONCLUSIONS

CB2-based PVI in patients with HFrEF appeared to be safe, was associated with comparable periprocedural complications and showed promising clinical success rates equal to those for patients with preserved LVEF. NYHA class and LVEF significantly improved at 12-month follow-up.

Association between gene variants and the recurrence of atrial fibrillation: An updated meta-analysis

BACKGROUND

Studies showed the controversial results about the effect of common genetic polymorphisms on the atrial fibrillation (AF) recurrence. We performed the systematic review and meta-analysis to qualify the association between common genetic polymorphisms and AF recurrence.

METHODS

Articles were systematically retrieved PubMed, Web of Science, EMBASE, Wanfang, and CNKI database and 9 studies including 3204 patients were enrolled in our meta-analysis.

RESULTS

Results showed that the associations were significant under rs2200733 3 genetic models (TT vs CC: odds ratio [OR] [confidence interval [CI]] = 1.336 [1.061-1.683], P = .014; CT vs CC: OR [CI] = 0.759 [0.614-0.937], P = .01; TT vs CT + CC: OR [CI] = 2.308 [1.440-3.700], P = .001). The association was significant under rs10033464 genetic model (TT vs GG: OR [CI] = 1.517 [1.165-1.976], P = .002).

CONCLUSIONS

Rs13376333 on chromosome 1q21 (in KCNN3), rs7193343 and rs2106261 on chromosome 16q22 (in ZFHX3) were not associated with AF recurrence in our meta-analysis. In total, our meta-analysis found that rs2200733 and rs10033464 on chromosome 4q25 (near PITX2) were associated with the risk of AF recurrence.

Long-term outcomes of cryoballoon pulmonary vein isolation for paroxysmal and persistent atrial fibrillation in Chinese patients

PURPOSE

We aimed to study the long-term outcomes of cryoballoon (CB) pulmonary vein isolation (PVI) in treating Chinese patients with atrial fibrillation (AF).

METHODS

A total of 122 patients (48 women, mean age 57.4 ± 11.3) underwent CB PVI (first generation CB 44.3%, second generation CB 55.7%) for AF (paroxysmal 65.6%, persistent 10.7% and long-standing persistent 23.8%).

RESULTS

PVI was achieved in 113 (92.6%) patients with CB alone, and it was achieved in all patients with additional touch-up by 8-mm-tip cryocatheter. The mean procedural and fluoroscopic duration were 171.9 ± 41 and 46.6 ± 14.6 min respectively. The recurrence-free survival for paroxysmal and non-paroxysmal AF was 77% and 59% respectively at 1 year and progressively declined over time to reach a plateau of 52% and 30% for paroxysmal and non-paroxysmal AF respectively at 5 years. In patients undergoing PVI with second-generation CB, the recurrence-free survival was 75% for paroxysmal AF and 45% for non-paroxysmal AF at 5 years. With multivariate Cox regression analysis, the types of CB (use of second-generation CB: HR 0.49; 95% CI 0.28-0.85; p = 0.011) and size of left atrium (LA) (larger LA size: HR 1.52; 95% CI 1-2.14; p = 0.017) independently predicted recurrence. Transient phrenic nerve injury (PNI) occurred in four (3.3%) patients and persistent PNI occurred in four (3.3%) patients. Other complications occurred in 10 (8.2%) patients with no procedure-related death.

CONCLUSIONS

Long-term success of CB PVI for AF declined over time and reached a plateau at 5 years. CB types and LA size are independent predictors for long-term recurrence.

Alternative strategies to improve success rate of mitral isthmus block

Achieving bidirectional conduction block (BDB) across the mitral isthmus (MI) is technically challenging. We describe our experience using different ablation strategies for achieving successful MI block.We reviewed the records of patients who had undergone MI ablation for peri-mitral (PM) flutter at our institution from January 2010 to May 2015. We investigated ablation strategies for achieving MI block and their long-term outcomes in terms of recurrence of atrial tachyarrhythmia.Single endocardial MI ablation with or without distal coronary sinus (CS) ablation achieved MI block in 129 out of 236 (54.7%) patients. After failure of MI block, a new MI line ablation, ablation targeting the vein of Marshall (VOM), or anterior line ablation was performed in selected patients. The MI block was achieved in 13 (52.0%) out of 25 patients with new MI line ablation and in 13 (68.4%) out of 19 patients with VOM ablation. Anterior line ablation was tried in 23 patients and the line of block was achieved in 12 (52.2%) patients. Finally, overall PM BDB (PMB, MI block or anterior line block) was achieved in 167 (70.8%) of 236 patients. The incidence atrial tachyarrhythmia was similar between the patients with successful PMB and those with failed PMB (32.9% vs 42.0%, P = .18). In multivariable Cox regression analysis, the PMB was not associated with recurrence of atrial tachyarrhythmia (hazard ratio [HR]: 0.70, 95% confidence interval [CI]: 0.43-1.12).In conclusion, single endocardial MI line with or without distal CS ablation showed limited success for achieving MI block. Additional substrate modifications such as a new MI line ablation, anterior line ablation, or ablation targeting the VOM may improve the success rate of PMB block. However, the benefits of PMB were not clear in this study.

Clinical outcome of the 2nd generation cryoballoon for pulmonary vein isolation in patients with persistent atrial fibrillation - A sub-study of the randomized trial evaluating single versus dual cryoballoon applications

AIMS

To assess the efficacy of the 2nd generation Cryoballoon for pulmonary vein isolation (PVI) in patients with persistent atrial fibrillation (PersAF), and to compare it to patients with paroxysmal atrial fibrillation (PAF).

METHODS

The outcome (arrhythmia recurrence at 12 months) was prospectively assessed in patients with PersAF(n = 77) and compared to that in patients with PAF(n = 62), who underwent PVI within a randomized trial evaluating single versus dual applications with the 2nd generation cryoballoon. Other endpoints included symptoms of AF, quality of life, procedure related characteristics, redo ablation rates and adverse events. Variables predicting recurrences were studied including all patients.

RESULTS

Freedom from arrhythmia recurrence was 64.9% after a single ablation and 68.8% after one or more procedures, which was significantly lower compared to PAF patients; 82.2% (p = 0.029) and 83.9% (p = 0.048) respectively, at 12 months. The improvements in EHRA score (-1.3 ± 0.8, p < 0.0001), symptom severity score (SSQ) (-5.0 ± 4.2, p < 0.0001) and EQ5D-5 L global score (+10.4 ± 20.3, p = 0.0002) after ablation was significant compared to baseline. The re-ablation rate was 7/77 (9.1%) which did not differ from that in PAF patients, 9/62 (14.5%), p = 0.42. Procedure duration, 104.8 ± 37.4 versus 113 ± 31.2 min (p = 0.129), application time, 1605 ± 659 versus 1521 ± 557 s (p = 0.103) and total adverse events after 12 months, 8/77 (10.4%) versus 5/62 (8.1%) (p = 0.77) did not differ in PersAF versus PAF patients.

CONCLUSION

Both symptoms and QoL improved significantly in patients with PersAF after ablation. Freedom from AF was clinically significant but lower than in PAF patients. The cryoballoon seems an effective technique also in patients with persistent AF.

Second-generation cryoballoon for pulmonary vein isolation in patients with pulmonary vein abnormality: Safety, efficacy and lessons from re-ablation procedures

Second generation cryoballoon (CB) has been shown to be effective for treatment of paroxysmal and persistent atrial fibrillation (AF). However, the fixed size of the non-compliant balloon may limit its use in patients with pulmonary vein (PV) abnormalities. In this study we investigated the acute success, procedural complications and long term outcome of CB based PV isolation (PVI) in patients with PV abnormality. A total of 238 patients [64.8 ± 11.1 years; 91 paroxysmal (38.2%), 147 persistent AF (61.8%)] underwent PVI using the second generation CB without preprocedural imaging. In 43/238 (18.1%) patients PV abnormality (left common PV in 26, right middle PV in 20) was observed. All targeted veins including abnormal PVs were isolated (100%). Transient phrenic nerve palsy (PNP) occurred in one (2.3%) patient in the PV anomalous group and 6 (3.0%) in the control group (p = NS). There was no other adverse event including PV stenosis, atrio-esophageal fistula or cerebrovascular events related to the procedure. During mean follow-up of 11.8 ± 5.4 month a total of 59 patients (24.7%) had atrial tachyarrhythmia (ATA) recurrence [27 (11.3%) had AT recurrence]. In the PV anomalous group, 20/43 (46.5%) patients had ATA recurrence compared to 39/195 (20%) in the control group (p < 0.001). AT recurrence was observed in 27 (11.3) patients [11 (25.5%) in the PV anomalous group and 16 (8.2%) in controls respectively, p = 0.003]. In patients with PV abnormality CB-based AF ablation results in a similar acute PVI rate but a higher ATA recurrence rate during follow up as compared to patients without PV abnormality.