Comparison of Cryoballoon and Radiofrequency Ablation of Pulmonary Veins in 40 Patients with Paroxysmal Atrial Fibrillation: A Case-Control Study

Atrial Fibrillation in Hypertrophic Cardiomyopathy

Atrial fibrillation (AF) is common among patients with hypertrophic cardiomyopathy (HCM) with a prevalence greater than 25%. AF in HCM is associated with a high risk of stroke and can be a marker of more advanced cardiomyopathy. Although, it frequently results in cardiac hemodynamic changes which are poorly tolerated, it can be subclinical. Thus, prompt diagnosis and adequate management of AF are essential to minimizing AF-related adverse outcomes in HCM. All HCM patients should be screened for AF regularly, and those with high-risk features should be screened more frequently preferably with extended ambulatory monitoring. Once AF is detected, oral anticoagulation should be initiated. Both general and HCM-specific modifiable risk factors should be addressed and assessment for cardiomyopathy progression should be performed. Although no randomized controlled studies have compared rate versus rhythm control in HCM, early rhythm control could be considered to prevent further LA remodeling.

Evaluation of risk factors for long-term atrial fibrillation development in patients undergoing typical atrial flutter ablation: a multicenter pilot study

BACKGROUND

Atrial flutter (AFL) and atrial fibrillation (AF) are the most commonly detected supraventricular arrhythmias and share similar pathophysiological mechanisms. After the successful ablation of AFL, AF frequently occurs in the long-term follow-up. As emphasized in some studies, certain mechanisms seem to predispose to the development of AF in AFL patients, and approximately 20% of these patients have accompanying AFL.

PURPOSE

We aimed to analyze independent risk factors that predict the development of AF in patients who underwent typical AFL ablation.

METHODS

This was a multicenter, cross-sectional, and retrospective study. A total of 442 patients who underwent typical AFL ablation at three different centers between January 1, 2018 and January 1, 2022 were included retrospectively. After the ablation procedure the patients were divided into those who developed AF and those who did not. The patients were followed up for an average of 12 (4-20) months. In the post-procedural period, atrial arrhythmias were investigated with 24‑h Holter and ECG at 1 month, 6 months, and 12 months and then at 6‑month intervals thereafter.

RESULTS

Overall, AF developed in 206 (46.6%) patients in the long-term follow-up. Age, hypertension (HT), obstructive sleep apnea syndrome (OSAS), previous cerebrovascular accident (CVA), left atrium anteroposterior diameter, severe mitral regurgitation, hemoglobin, blood glucose, and HbA1c values were found to be significant in univariable analysis. According to multivariable analysis, HT (p = 0.014; HR: 1.483 [1.084-2.030]), OSAS (p = 0.008; HR: 1.520 [1.117-2.068]) and previous CVA (p = 0.038; HR: 1.749 [1.031-2.968]) were independently associated with the development of AF in AFL patients who underwent ablation procedure.

CONCLUSION

In the present study, we found that HT, OSAS, and previous CVA were independently correlated with the development of AF in the long-term follow-up of patients who underwent typical AFL ablation. We consider that AFL patients with such risk factors should be followed up closely following cavotricuspid isthmus ablation for the development of AF.

Cost-utility analysis of Cryoballoon ablation versus Radiofrequency ablation in the treatment of paroxysmal atrial fibrillation in Iran

Atrial fibrillation (AF) is the most prevalent cardiac arrhythmia (Calkins H, et al. 2012). There are various methods to treat AF of which Ablation is one of the most effective. We aimed to assess the cost-utility of Cryoballoon ablation (CBA) compared to Radiofrequency ablation (RFA) to treat patients with paroxysmal AF in Iran. A cost-utility analysis was done using a decision-analytic model based on a lifetime Markov structure which was drawn considering the nature of interventions and the natural progress of the disease. Costs data were extracted from medical records of 47 patients of Shahid Rajaie Cardiovascular Medical Center in Tehran in 2019. Parameters and variables such as transition probabilities, risks related to side effects, mortality rates, and utility values were extracted from the available evidence. Deterministic and probabilistic sensitivity analysis was also done. TreeAge pro-2020 software was used in all stages of analysis. In the base case analysis, the CBA strategy was associated with higher cost and effectiveness than RFA, and the incremental cost-effectiveness ratio was $11,223 per Quality-adjusted life year (QALY), which compared to Iran’s GDP per capita as Willingness to pay threshold, CBA was not cost-effective. On the other hand, considering twice the GDP per capita as a threshold, CBA was cost-effective. Probabilistic sensitivity analysis confirmed the findings of base case analysis, showed that RFA was cost-effective and the probability of cost-effectiveness was 59%. One-way sensitivity analysis showed that the results of the study have the highest sensitivity to changes in the RFA cost variable. Results of sensitivity analysis showed that the cost-effectiveness results were not robust and are sensitive to changes in variables changes. Primary results showed that CBA compared to RFA is not cost-effective in the treatment of AF considering one GDP per capita. But the sensitivity analysis results showed considerable sensitivity to changes of the ablation costs variable.

The Long-Term Results of Three Catheter Ablation Methods in Patients With Paroxysmal Atrial Fibrillation: A 4-Year Follow-Up Study

Aims: Catheter ablation of paroxysmal atrial fibrillation (PAF) has been shown to be effective and safe. However, recurrence of PAF varies between 10 and 30% for radiofrequency ablation. There have been no reports comparing long-term recurrence rates following radiofrequency ablation, cryoablation, and three-dimensional guided cryoablation plus radiofrequency ablation. The aim of this study was to observe the long-term recurrence rate of PAF when treated by these three catheter ablation methods, and to explore clinical factors that can potentially predict PAF recurrence following catheter ablation. Methods: There were 238 patients involved in this study, including 106 radiofrequency (RF) ablation cases (RF group), 66 cryoablation cases (Freeze group), and 66 cases treated by three-dimensional guided cryoablation combined with radiofrequency ablation (Freeze-plus-RF group). All patients underwent standardized follow-up. The recurrence rate of atrial fibrillation (AF) in the three groups was calculated. Predictive factors for the recurrence of AF were also investigated. Results: At 48 months (the median follow-up period), the sinus rhythm maintenance rate was 77.4% in the RF group, 72.7% in the Freeze group, and 81.8% in the Freeze-plus-RF group. The maintenance rate of sinus rhythm was highest in the Freeze-plus-RF group, but differences among the three groups were not statistically significant. Further analysis found that the preoperative left atrial appendage emptying velocity (LAAEV) (recurrence vs. no recurrence, 56.58 ± 18.37 vs. 65.59 ± 18.83, respectively, p = 0.003), left atrial (LA) anteroposterior dimension (recurrence vs. no recurrence, 36.56 ± 4.65 vs. 35.00 ± 4.37, respectively; p = 0.028), and LA vertical dimension (recurrence vs. no recurrence, 56.31 ± 6.96 vs. 53.72 ± 6.52, respectively; p = 0.035) were related to postoperative recurrence. Multiple Cox regression analysis showed that only LAAEV was predictive of postoperative recurrence of PAF (hazard ratio: 0.979; 95% confidence interval: 0.961-0.997). Conclusion: Our study found that there was no statistically significant difference in long-term recurrence rates among the RF, Freeze, and Freeze-plus-RF groups. Preoperative LAAEV is an independent predictor of postoperative recurrence of PAF.

Preventing atrial fibrillation by combined right isthmus ablation and cryoballoon pulmonary vein isolation in patients with typical atrial flutter: PAF-CRIOBLAF study

BACKGROUND

Although less common, typical atrial flutter shares similar pathophysiological roots with atrial fibrillation. Following successful cavo-tricuspid isthmus ablation using radiofrequency, many patients, however, develop atrial fibrillation in the mid-to-long-term. This study sought to assess whether pulmonary vein isolation conducted at the same time as cavo-tricuspid isthmus ablation would significantly modify the atrial fibrillation burden upon follow-up in patients suffering from typical atrial flutter.

METHODS

This was a multicenter randomized controlled study involving typical atrial flutter patients with history of non-predominant atrial fibrillation (1 atrial fibrillation episode only, in 67% of population) who were scheduled for cavo-tricuspid isthmus radiofrequency ablation. Patients were randomly assigned to either undergo cavo-tricuspid isthmus ablation alone or cavo-tricuspid isthmus plus pulmonary vein isolation (CTI+). Pulmonary vein isolation was performed using cryoballoon technology. An outpatient consultation with ECG and 1-week Holter monitoring was performed at 3, 6 months, 1 year, and 2 years postprocedure. The primary endpoint was atrial fibrillation recurrences lasting more than 30 s at 2 years postablation.

RESULTS

Of the patients enrolled, 36 were included in each group. At 2-year follow-up, the atrial fibrillation recurrence rate was significantly higher in the CTI vs CTI+group (25/36, 69% vs. 12/36, 33% respectively; P < .001), with similar typical atrial flutter recurrence rates. There were no differences in undesirable events, except for transient phrenic nerve palsy reported from three CTI+patients (8.3%).

CONCLUSION

Pulmonary vein isolation using cryoballoon technology was proven to significantly reduce the atrial fibrillation incidence at 2 years postcavo-tricuspid isthmus ablation.

In Vitro Cell Selectivity of Reversible and Irreversible: Electroporation in Cardiac Tissue

[Figure: see text].

Radiation exposure in cryoballoon ablation compared to radiofrequency ablation with three-dimensional electroanatomic mapping in atrial fibrillation patients

BACKGROUND

Catheter ablation for atrial fibrillation (AF) has become an established treatment to control symptoms. AF ablation either by cryoballoon or radiofrequency using three-dimensional (3D) electroanatomical mapping exposes patients and medical staff to increased doses of radiation.

AIM

To compare radiation exposure in patients during cryoballoon ablation compared to 3D electro-anatomic mapping catheter ablation in AF patients.

METHODS

A total of 30 patients referred for AF ablation underwent full history taking, 12-lead ECG, echocardiogram, and pulmonary vein isolation either by 3D mapping system or cryoballoon. Procedure duration and fluoroscopy time were collected and analyzed. Radiation exposure was measured using thermoluminescent dosimeters placed at different sites related to patients and medical staff.

RESULT

The procedural time was statistically significantly longer with 3D mapping compared to cryoballoon but showed no significant difference regarding fluoroscopy time. There was a significantly higher radiation skin dose at the right scapular area in the cryoballoon ablation group, in addition to higher peak skin dose compared to the 3D mapping ablation group. There was no statistically significant correlation between peak skin doses and fluoroscopy duration but a statistically significant correlation between peak skin dose and usage of high frame rate and the high dose area product.

CONCLUSION

Cryoballoon ablation was found to be associated with higher peak skin radiation doses especially in the right scapular area. Knowing dose area product and peak skin dose is more important than fluoroscopy time alone.

Cryoballoon Ablation for the Treatment of Atrial Fibrillation: A Meta-analysis

BACKGROUND

Ablation therapy is the treatment of choice in antiarrhythmic drugrefractory atrial fibrillation (AF). It is performed by either cryoballoon ablation (CBA) or radiofrequency ablation. CBA is gaining popularity due to simplicity with similar efficacy and complication rate compared with RFA. In this meta-analysis, we compare the recurrence rate of AF and the complications from CBA versus RFA for the treatment of AF.

METHODS

We systematically searched PubMed for the articles that compared the outcome of interest. The primary outcome was to compare the recurrence rate of AF between CBA and RFA. We also included subgroup analysis with complications of pericardial effusion, phrenic nerve palsy and cerebral microemboli following ablation therapy.

RESULTS

A total of 24 studies with 3527 patients met our predefined inclusion criteria. Recurrence of AF after CBA or RFA was similar in both groups (RR: 0.84; 95% CI: 0.65, 1.07; I2=48%, Cochrane p=0.16). In subgroup analysis, heterogeneity was less in paroxysmal AF (I2=0%, Cochrane p=0.46) compared to mixed AF (I2=72%, Cochrane p=0.003). Procedure and fluoroscopy time was less by 26.37 and 5.94 minutes respectively in CBA compared to RFA. Complications, pericardial effusion, and silent cerebral microemboli, were not different between the two groups, however, phrenic nerve palsy was exclusively present only in CBA group.

CONCLUSION

This study confirms that the effectiveness of CBA is similar to RFA in the treatment of AF with the added advantages of shorter procedure and fluoroscopy times.

Long Term Outcome and Pulmonary Vein Reconnection of Patients Undergoing Cryoablation and/or Radiofrequency Ablation: Results from The Cryo Versus RF Trial

Introduction

Long term prospective data comparing the efficacy of radiofrequency (RF) and cryoballoon ablation (CRYO) for paroxysmal atrial fibrillation (PAF) is lacking. We report the long-term outcomes of a randomized control trial comparing CRYO to RF ablation, or a novel COMBINED approach (RF followed by CRYO) for PAF. We studied the number and pattern of pulmonary vein (PV) reconnections in patients undergoing repeat procedure(s). The COMBINED approach had significantly higher single procedure success rate and is associated with the fewest reconnected PVs.

Methods

203 patients who underwent first time PAF ablation in a randomized clinical trial comparing CRYO (67), RF (67) and COMBINED (69) approaches were followed up. All patients with symptomatic recurrence of AF were offered a repeat procedure(s). Reconnected PV(s) at repeat procedure(s) were recorded. In a subset, the PV reconnection sites during the first repeat procedure were prospectively assessed and categorised into one of 8 segments. .

Results

At 5 years, 57% of COMBINED patients remained free of AF after a single procedure compared to 47% CRYO and 19% RF patients (p<0.001 COMBINED vs RF and CRYO vs RF, p=0.043 COMBINED vs CRYO). During the first repeat procedure, theCOMBINED group had less number of reconnected PVs (mean number of reconnected PVs in the COMBINED group 1.2 vs 2.3 CRYO and 2.4 RF, p=0.034). There was a different pattern of PV reconnection comparing the CRYO and RF groups.

Conclusion

The COMBINED approach had a significantly higher single procedure success rate with fewer reconnected PVs and fewer reconnection sites compared to either CRYO or RF alone. CRYO in turn was superior to RF. PV reconnection pattern differed between CRYO and RF and the synergistic effect of the COMBINED approach may explain the improved single procedure efficacy.

The Role of Echocardiography in Determining the Method of Ablation for the Treatment of Paroxysmal Atrial Fibrillation: A Literature Review

Atrial fibrillation is the most common cardiac arrhythmia, affecting approximately 1 out of every 250 people. It is associated with thrombus formation in the left atrium, decreased cardiac output, and deterioration of the myocardium. There are multiple treatments available for paroxysmal atrial fibrillation. This literature review will assess the benefits, risks, and complications associated with radiofrequency ablation and cryoablation, which utilize heat and freezing mechanisms, respectively. The review will also assess the role of echocardiography in determining which treatment, if any, is appropriate for atrial fibrillation.

The Role of Protein Loss and Denaturation in Determining Outcomes of Heating, Cryotherapy, and Irreversible Electroporation on Cardiomyocytes

Atrial fibrillation (AF) currently affects millions of people in the U.S. alone. Focal therapy is an increasingly attractive treatment for AF that avoids the debilitating effects of drugs for disease control. Perhaps the most widely used focal therapy for AF is heat-based radiofrequency (heating), although cryotherapy (cryo) is rapidly replacing it due to a reduction in side effects and positive clinical outcomes. A third focal therapy, irreversible electroporation (IRE), is also being considered in some settings. This study was designed to help guide treatment thresholds and compare mechanism of action across heating, cryo, and IRE. Testing was undertaken on HL-1 cells, a well-established cardiomyocyte cell line, to assess injury thresholds for each treatment method. Cell viability, as assessed by Hoechst and propidium iodide (PI) staining, was found to be minimal after exposure to temperatures ≤−40 °C (cryo), ≥60 °C (heating), and when field strengths ≥1500 V/cm (IRE) were used. Viability was then correlated to protein denaturation fraction (PDF) as assessed by Fourier transform infrared (FTIR) spectroscopy, and protein loss fraction (PLF) as assessed by bicinchoninic acid (BCA) assay after the three treatments. These protein changes were assessed both in the supernatant and the pellet of cell suspensions post-treatment. We found that dramatic viability loss (≥50%) correlated strongly with ≥12% protein change (PLF, PDF or a combination of the two) in every focal treatment. These studies help in defining both cellular thresholds and protein-based mechanisms of action that can be used to improve focal therapy application for AF.

New migraine with visual disturbance after cryoballoon ablation of atrial fibrillation

We report the case of a 58-year-old woman who developed a headache and visual disturbances after a cryoballoon ablation procedure for atrial fibrillation at our institution. She presented to the emergency department four days post ablation and was admitted the hospital for overnight observation. Serial neurological examinations and neuroimaging were unremarkable for stroke or transient ischemic attack. The patient had some brief transient visual changes which resolved completely after several days, with no further clinical sequelae. She followed up in the outpatient neuro-ophthalmology clinic and had a normal visual field examination. She was given a diagnosis of new onset migraine with visual aura.

Cryoballoon ablation in atrial fibrillation: Advantages and drawbacks

Pulmonary vein isolation is the cornerstone of atrial fibrillation ablation and is effective for preventing arrhythmias recurrences, especially in patients with paroxysmal atrial fibrillation. During the last years, cryoballoon ablation has emerged as an unquestionable alternative approach to radiofrequency ablation. Many non-randomized and randomized trials have proven undoubtedly that cryoballoon ablation displays similar efficacy and overall safety profile, when compared to radiofrequency ablation for the treatment of patients with drug-refractory paroxysmal atrial fibrillation. These results have been obtained in all types of pulmonary veins anatomical subsets, which confirms that there is no need to select patients according to the latter. The value of cryoablation in the setting of short persistent atrial fibrillation still needs more evidence. Importantly, cryoballoon ablation seems to be less operator-dependent and more reproducible than radiofrequency for the isolation of pulmonary veins.

Cryoballoon vs. radiofrequency ablation for paroxysmal atrial fibrillation: an updated meta-analysis of randomized and observational studies

Aims

Radiofrequency (RF) ablation represents a standard of care for pulmonary vein isolation in patients with drug-refractory paroxysmal atrial fibrillation (AF). In this setting, cryoballoon (CB) ablation has emerged as alternative therapy. However, the efficacy and safety of CB vs. RF ablation in patients with paroxysmal AF remain a matter of debate.

Methods and results

We searched electronic scientific databases for studies of CB vs. RF ablation in patients with paroxysmal AF. Aggregate data were pooled to perform a meta-analysis. The primary efficacy and safety outcomes were the recurrence of any atrial arrhythmia and procedure-related complications, respectively. A total of 6473 participants from 10 studies (CB, n = 2232 vs. RF, n = 4241) were studied. After a median follow-up of 16 months, the risk of any atrial arrhythmia recurrence (risk ratio, RR 95% confidence interval [95% CI] = 1.01 [0.90-1.14], P = 0.83) and procedure-related complications (RR [95% CI] = 0.92 [0.66-1.28], P = 0.61) were comparable between CB vs. RF ablation. Cryoballoon ablation led to a higher risk of persistent phrenic nerve palsy (RR [95% CI] = 13.60 [3.87-47.81], P < 0.01) and a lower risk of cardiac tamponade (RR [95% CI] = 0.48 [0.25-0.89], P = 0.02) compared with RF ablation. There was a trend of statistically significant interaction between the type of CB and the duration of ablation (P for interaction = 0.09).

Conclusion

In patients with paroxysmal AF, ablation therapy with CB is associated with efficacy and safety comparable to that of RF. Second-generation CB catheters seem to reduce procedure duration. Further studies are warranted to disclose the impact of second-generation CB catheters compared with RF for ablation of paroxysmal AF.

Efficacy of second-generation cryoballoon ablation in paroxysmal and persistent atrial fibrillation patients

AIMS

In this study, we aimed to compare the efficacy of single pulmonary vein isolation with the second-generation cryoballoon (CB-Adv) and predictors of atrial fibrillation recurrences in patients with paroxysmal (PAF) and persistent atrial fibrillation (PersAF).

METHODS

Consecutive PAF and PersAF patients undergoing CB-Adv for the first time were enrolled. Patients were followed with in-clinic visits including Holter ECG. Atrial arrhythmic episodes symptomatic or documented lasting more than 30 s were considered as recurrences.

RESULTS

A total of 96 consecutive patients [77 men (80%), mean age 57.4 ± 9.9 years] were included in this analysis. About 56 (58%) patients had PAF and 40 had (42%) PersAF. The mean procedural and fluoroscopy times were 116 ± 24 and 33 ± 12 min, respectively. Procedure-related complications occurred in four (4.2%) patients.At the 12-month follow-up, after a 3-month blanking period, freedom from recurrences was achieved in 59% [confidence interval (CI): 49-69%] of patients, 62% (CI: 48-75%) in PAF, and 54% (CI: 38-71%) in PersAF group. The difference was not statistically significant at the Kaplan-Meier survival analysis (P = 0.242). Cardioversion to restore sinus rhythm was less frequently needed in PAF group [5% (CI: 1-15%) vs. 25% (CI: 13-41%), P < 0.001]. Redo procedure was performed in 7% (CI: 3-15%) of patients. In the Cox regression analysis, early atrial-tachyarrhythmia recurrence was the only independent predictor of 1-year recurrence (hazard ratio 2.11, CI: 1.06-4.20, P = 0.03).

CONCLUSION

The success rate at 12 months after a single CB-Adv procedure was 62% in patients with PAF and 54% in study participants with PersAF. Early atrial-tachyarrhythmia recurrence appeared to be the only independent predictor of late atrial fibrillation recurrence.

Pulmonary Vein Isolation with the Cryoballoon Technique: Feasibility, Procedural Outcomes, and Adoption in the Real World: Data from One Shot Technologies TO Pulmonary Vein Isolation (1STOP) Project

BACKGROUND

Catheter ablation (CA) is recommended for patients with drug refractory symptomatic atrial fibrillation (AF). "One Shot" catheters have been introduced to simplify CA and cryoballoon ablation (CBA) is spreading rapidly. Few real-world data are available on standard clinical practice, mainly from single-center experience. We aimed to evaluate clinical settings, demographics, and acute procedural outcomes in a large cohort of patients treated with CBA.

METHODS

A total of 903 patients (73% male, mean age 59 ± 11) underwent pulmonary vein CBA. Correlations between the patient's inclusion time and clinical characteristics, procedure duration, acute success rate, and intraprocedural complications were evaluated.

RESULTS

Seventy-seven percent of patients were affected by paroxysmal AF and 23% by persistent AF. Overall, acute success rate was 97.9% and periprocedural complications were observed in 35 (3.9%) patients, 13 (1.4%) of which were classified as major complications. With respect to the patient's inclusion time analysis, an increase in treatment of persistent AF was observed, a significant decrease in CBA times (procedure, ablation, and fluoroscopy: 136.0 ± 46.5 minutes, 28.8 ± 19.6 minutes, and 34.3 ± 15.4 minutes, respectively) was observed, with comparable acute success rate and intraprocedural complications over time. The rate of major complications was extremely low (1.4%); no death, atrioesophageal fistula, stroke, or other major periinterventional or late complications occurred.

CONCLUSION

This series represents the largest experience of CBA in the treatment of AF that also describes the adoption curve of this relatively recent technology. CBA showed an excellent safety profile when performed in a large real-world clinical setting, with satisfactory acute success rate and, on average, short procedural times.

CLINICAL TRIAL REGISTRATION

clinicaltrials.gov (NCT01007474).

The Hot and the Cold: Radiofrequency Versus Cryoballoon Ablation for Atrial Fibrillation

Catheter ablation is superior to antiarrhythmic drugs in maintaining sinus rhythm for patients with atrial fibrillation (AF). Pulmonary vein (PV) isolation is the cornerstone of any AF ablation procedure. Conventionally, this is achieved by performing point by point lesions using radiofrequency (RF) energy. However, this is technically challenging, time consuming and is associated with a number of complications. Long-term durability of PV isolation is also a concern. To address these issues, 'one-shot' energy delivery systems and alternative energy sources have been developed. The cryoballoon system has emerged as the most commonly used alternative to point by point RF technology. In this paper, we compare the technology, biophysics and clinical data of cryoballoon to conventional RF ablation for AF. The safety and efficacy of cryoballoon compared to RF ablation is critically reviewed. We conclude by looking at future applications of this technology.

Results from a multicentre comparison of cryoballoon vs. radiofrequency ablation for paroxysmal atrial fibrillation: is cryoablation more reproducible?

AIM

Cryoballoon ablation (Cryoballoon) has emerged as a new alternative for the treatment of symptomatic drug-refractory atrial fibrillation (AF). Whether the results of Cryoballoon are more reproducible than those of radiofrequency (RF) ablation remains to be proved.

METHODS AND RESULTS

A total of 860 consecutive patients undergoing a first ablation procedure for paroxysmal AF (467 treated with RF and 393 treated with Cryoballoon) were selected from a prospective multicentre survey of AF ablation (FrenchAF). Radiofrequency and Cryoballoon were compared regarding mid-term efficacy and safety. During a median follow-up of 14 months (interquartile range 8-23), patients treated with Cryoballoon displayed similar rates of freedom from atrial arrhythmia relapse in centres performing this technique (68-80% at 18 months). However, in centres performing RF, a greater heterogeneity in procedural results was observed (46-79% were free from atrial arrhythmia relapse at 18 months). On multivariate analysis, Cryoballoon (HR = 0.47, 95% CI 0.35-0.65, P < 0.001) and annual AF ablation caseload (HR = 0.87 per every 100 AF ablation procedures per year; 95% CI 0.80-0.96, P = 0.003) were independent predictors of procedural success. However, on sensitivity analysis, according to the ablation method, annual AF ablation caseload predicted only sinus rhythm maintenance in the subgroup of patients treated with RF. Analysis of interoperator results with Cryoballoon and RF confirmed lower reproducibility of RF, but suggested that besides caseload, other operator-related factors may play a role.

CONCLUSION

Cryoballoon seems to be less operator-dependent and more reproducible than RF in the setting of paroxysmal AF ablation.

[Transseptal puncture after device closure of patent foramen ovale: Is it feasible?]

CASE REPORT

The case of a 40-year-old woman with paroxysmal symptomatic atrial fibrillation and implanted occluder of a patent foramen ovale (PFO; AMPLATZER™ Septal Occluder, St. Jude Medical) is reported. Due to the symptomic atrial fibrillation, pulmonary vein isolation was planned.

METHODS

Under transesophageal, echocardiographic control the transseptal puncture was performed posterior inferior of the occluder without any complications. The pulmonary vein was successfully isolatedusing radiofrequency energy.

CONCLUSION

This case demonstrates that transseptal puncture in pulmonary vein isolation with an inserted PFO occluder under additional transesophageal, echocardiographic monitoring is safe and feasible.

Long Term Follow-up of Pulmonary Vein Isolation Using Cryoballoon Ablation

BACKGROUND

Cryoballoon ablation is an established catheter-based approach to treating atrial fibrillation (AF). There is little data regarding the long-term efficacy of this approach.

METHODS

We enrolled 200 consecutive patients with symptomatic AF who had failed therapy with at least one anti-arrhythmic medication and followed them for five years. The primary efficacy endpoint was symptomatic recurrence of AF after a single cryoballoon ablation procedure.

RESULTS

Two hundred patients formed the study group. Median follow-up was 56 months. Following a single procedure, 46.7% of patients with paroxysmal AF remained free of symptomatic recurrence of AF compared to 35.6% of patients with persistent AF. When allowing for repeat ablations, at the end of the follow-up period 53.3% of patients in the paroxysmal group remained free of symptomatic AF compared to 47.5% in the persistent group. The rate of complications was low.

CONCLUSIONS

Cryoballoon ablation is an effective catheter-based approach for treating symptomatic AF with a low risk of complications.

Successful intraprocedural anticoagulation with bivalirudin during pulmonary vein isolation in a patient with known heparin-induced thrombocytopenia type II

We report the case of a 56-year-old female who presented with symptomatic paroxysmal atrial fibrillation. Anamnestic heparin-induced thrombocytopenia (HIT) type II was suspected, and a rapid diagnostic test showed antibodies against platelet factor 4. The heparin-induced platelet activation-assay was negative. Radiofrequency pulmonary vein isolation with intraprocedural anticoagulation using bivalirudin was ultimately performed. Dosing was controlled by monitoring the activated clotting time. Post-procedural blood tests were normal. There were no thromboembolic or bleeding events. Bivalirudin is a therapeutic option for anticoagulation during pulmonary vein isolation procedures in patients with a history of HIT type II.

Outcomes Of Cryoballoon Ablation Of Atrial Fibrillation: A Comprehensive Review

Over the last decade, cryoballoon ablation has emerged as an effective alternate strategy to point-by-point radiofrequency ablation for treatment of symptomatic atrial fibrillation. There are several reasons for this. First, the acute and long-term safety and efficacy associated with cryoablation appear comparable to that of radiofrequency ablation in patients with both paroxysmal and also persistent atrial fibrillation. Second, cryoablation offers certain advantages over conventional radiofrequency ablation including a gentler learning curve, shorter ablation and procedure times as well as lack of need for costly electroanatomical mapping technologies commonly utilized with radiofrequency ablation. Lastly, with the recent advent of the second-generation cryoballoon, the effectiveness of cryoablation has further improved dramatically. This comprehensive review examines the gradual evolution of the cryoablation tools as well as the rationale and data in support of the currently-available cryoballoon technologies for catheter ablation of atrial fibrillation.

Headache during cryoballoon ablation for atrial fibrillation

AIMS

Headache has been reported to occur during cryoballoon ablation for atrial fibrillation (AF). No study has systematically analysed this phenomenon.

METHODS AND RESULTS

Twenty consecutive patients with symptomatic AF underwent cryoballoon ablation without sedation. Headache was evaluated before, during, and after the first cryoapplication in every pulmonary vein (PV) using a visual representation of a head for location of the headache, a numerical rating scale (NRS) for measuring pain intensity and the short-form McGill pain questionnaire (MPQ) for qualitative analysis of pain. The order in which the PVs were ablated was randomized. Sixteen (80%) patients perceived mainly frontal headache during cryoablation. The overall NRS scores were significantly higher during (5.1 ± 1.7), compared with before (2.7 ± 1.4), and after (3.5 ± 2.2) a cryoapplication (P < 0.05). The NRS score was significantly higher during ablation of the first PV. The intensity of the perceived headache was not related to the temperature reached 150 s after initiation of a cryoapplication (P = 0.81). Of the MPQ, three sensory adjectives and one affective adjective averaged between scores 1 and 2, representing mild-to-moderate severity of pain.

CONCLUSION

The majority of patients treated by balloon cryoablation experienced headache during a cryoapplication. There was no correlation between the temperature reached during a cryoballoon freeze and the intensity of the headache. Cryoballoon ablation of the first PV was significantly more painful than the remaining PVs.

Atrial fibrillation ablation in the era of cryoballoon and force-sensing catheters: freeze or burn?

OPINION STATEMENT

Atrial fibrillation can adversely affect the quality of life for many patients. Though antiarrhythmic drug therapy remains an option for the treatment of atrial fibrillation, the drugs are associated with numerous side effects. Atrial fibrillation ablation has been shown to be as efficacious as antiarrhythmic drug therapy. The field of atrial fibrillation ablations has evolved over time from utilizing radiofrequency energy to using cryoenergy. Newer technologies are being developed with efforts to improve outcomes in patients undergoing atrial fibrillation ablations. This article will highlight two such technologies: cryoballoon ablation catheters and contact force-sensing catheters. These novel catheters appear to be further revolutionizing this young field in electrophysiology.

Improved Resource Utilization With Similar Efficacy During Early Adoption of Cryoballoon Pulmonary Vein Isolation as Compared to Radiofrequency Ablation for Paroxysmal Atrial Fibrillation

BACKGROUND

Cryoballoon pulmonary vein isolation (PVI) is an alternative to radiofrequency (RF) PVI for the treatment of paroxysmal atrial fibrillation (AF). Treatment effect, complication rates, and hospital length of stay are not well established with early use of cryoballoon PVI as compared to more experienced performance of RF PVI.

PURPOSE

We reviewed the early experience of cryoballoon PVIs for paroxysmal AF performed by 3 operators at our institution compared to their most recent RF PVIs. All repeat procedures were excluded. Patients were assessed for recurrence of AF at 6 months after the procedure, including a 3-month blanking period. Complications, procedure time, and hospital length of stay were recorded.

METHODS

Consecutive patients presenting to the ER with ECG-documented AF at an urban teaching hospital were treated according to a guideline-based care protocol, including a patient toolkit at ER discharge, and systematic referral to a rapid access AF clinic. Consenting patients received questionnaires on AF knowledge, patient satisfaction, and the AFEQT questionnaire at first visit and three-month follow-up.

RESULTS

Final analysis included 50 cryoballoon PVIs and 50 RF PVIs. There was no significant difference in baseline characteristics or percentage of patients wearing a home monitor (80% for cryoballoon vs 80% for RF). Symptomatic improvement was experienced by 96% of cryoballoon PVI as compared to 86% of RF PVI patients (p=0.08). Freedom from AF at 6 months was similar between the two groups (70% for cryoballoon and 70% for RF, p=1). Complications were seen in 6% of cryoballoon procedures as compared to 10% of RF procedures (p=0.46). Hospital length of stay was significantly shorter in the cryoballoon group (1.6 vs 3.4 nights, p=0.003).

CONCLUSION

At the time of its adoption, cryoballoon PVI is associated with shorter procedure times and hospital length of stay as compared to RF PVI in experienced operators while maintaining similar efficacy outcomes and complication rates.

Rationale and Design of FIRE AND ICE: A multicenter randomized trial comparing efficacy and safety of pulmonary vein isolation using a cryoballoon versus radiofrequency ablation with 3D-reconstruction

BACKGROUND

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia imposing substantial morbidity and mortality. Catheter-based pulmonary vein isolation (PVI) using radiofrequency current (RFC) has become a standard treatment for drug-resistant and symptomatic paroxysmal AF (PAF). In recent years, the cryoballoon-based technique is increasingly used as a promising alternative with a short learning curve.

METHODS

The FIRE AND ICE trial is a prospective, randomized, controlled, open, blinded outcome assessment, noninferiority trial comparing cryoballoon-, and RFC-based PVI. Patients with drug-resistant PAF will be randomized in a 1:1 matrix in multiple European centers. The primary hypothesis is that cryoballoon ablation is not inferior to RFC ablation using 3-dimensional mapping with respect to clinical efficacy. The primary endpoint is defined as the time to first documented clinical failure, including: (1) recurrence of AF; (2) atrial flutter or atrial tachycardia; (3) prescription of class I or III antiarrhythmic drugs; or (4) re-ablation, whichever comes first, following a blanking period of 3 months after the index ablation procedure. The primary safety endpoint is a composite of death, stroke/transient ischemic attack, cardiac arrhythmias (apart from AF recurrence) causally related to the therapeutic intervention, and procedure-related serious adverse events.

CONCLUSION

The FIRE AND ICE trial compares 2 different technologies to perform catheter ablation of PAF with respect to efficacy and safety. It aims at providing objective data to guide selection and usage of ablation catheters in the treatment of AF.

Improvements In AF Ablation Outcome Will Be Based More On Technological Advancement Versus Mechanistic Understanding

Atrial fibrillation (AF) is one of the most common cardiac arrhythmias. Catheter ablation has proven more effective than antiarrhythmic drugs in preventing clinical recurrence of AF, however long-term outcome remains unsatisfactory. Ablation strategies have evolved based on progress in mechanistic understanding, and technologies have advanced continuously. This article reviews current mechanistic concepts and technological advancements in AF treatment, and summarizes their impact on improvement of AF ablation outcome.