Cryoballoon versus Radiofrequency Catheter Ablation in Atrial Fibrillation: A Meta-Analysis

Catheter Ablation for Atrial Fibrillation-Influence of Modifiable Risk Factors and Ablation Modality on Procedural Efficacy and Safety

BACKGROUND

Modifiable lifestyle risk factors, in particular obesity and related conditions, are important drivers of atrial fibrillation (AF), impacting the severity of symptoms and influence the efficacy and safety of treatment.

OBJECTIVE

The study aimed to assess the impact of modifiable lifestyle factors on the effectiveness and safety of AF ablation, and examine the procedural characteristics, efficacy, safety and cost outcomes of cryoballoon vs radiofrequency ablation, in a real-world clinical setting.

METHOD

Patients undergoing catheter ablation for AF (June 2017 to December 2020) were included in this retrospective analysis. Efficacy and safety outcomes were obtained from electronic medical records and state-wide databases. The primary outcome was successful isolation of the pulmonary veins and freedom from AF without repeat ablation or ongoing antiarrhythmic therapy at 12 months.

RESULTS

The study included 141 patients (mean age 60±11 years, 57% male). The average body mass index (BMI) was 29.2±5.6 kg/m2. Ablation by cryoballoon was undertaken in 59% (radiofrequency 41%). Acutely successful pulmonary vein isolation was achieved in 92%, however, only 52% (n=74) met the primary outcome (successful isolation of the pulmonary veins and freedom from AF without repeat ablation or ongoing antiarrhythmic therapy) at 12 months. Successful management of AF was more likely in patients with lower BMI (p=0.006; particularly with BMI <27 kg/m2; p=0.004) and weight (p=0.003), and in those without obstructive sleep apnoea (p=0.032). The only independent predictor of the primary outcome was BMI (β=0.25, p=0.004). Over 75% of complications occurred in those with BMI ≥27 kg/m2.

CONCLUSIONS

Catheter ablation for AF is more likely to be unsuccessful in patients with uncontrolled risk factors, particularly obesity. Risk factor optimisation may improve procedural success and reduce the risk of procedural complications.

Repeat catheter ablation for atrial fibrillation

Catheter ablation of atrial fibrillation (AF) is an established therapy that reduces AF burden, improves quality of life, and reduces the risks of cardiovascular outcomes. Although there are clear guidelines for the application of de novo catheter ablation, there is less evidence to guide recommendations for repeat catheter ablation in patients who experience recurrent AF. In this review, we examine the rationale for repeat ablation, mechanisms of recurrence, patient selection, optimal timing, and procedural strategies. We discuss additional important considerations, including treatment of comorbidities and risk factors, risk of complications, and effectiveness. Mechanisms of recurrent AF are often due to non-pulmonary vein (non-PV) triggers; however, there is insufficient evidence supporting the routine use of empiric lesion sets during repeat ablation. The emergence of pulsed field ablation may alter the safety and effectiveness of de novo and repeat ablation. Extrapolation of data from randomized trials of de novo ablation does not optimally inform efficacy in cases of redo ablation. Additional large, randomized controlled trials are needed to address important clinical questions regarding procedural strategies and timing of repeat ablation.

Pericarditis After Catheter Ablation for Atrial Fibrillation: Predictors and Outcomes

BACKGROUND

Catheter ablation is a mainstay of atrial fibrillation (AF) treatment. Acute pericarditis after ablation is 1 of the frequently observed complications. There is a significant lack of data on the incidence and predictors of postablation pericarditis.

OBJECTIVES

This study examines the incidence, characteristics, and predictors of pericarditis after AF ablation.

METHODS

Patients undergoing AF ablation from January 1, 2016, to March 31, 2022, at Johns Hopkins were prospectively enrolled in an AF ablation registry. A clinical diagnosis of acute pericarditis was established in accordance with 2015 European Society of Cardiology guidelines by the presence of at least 2 of the following characteristics: pleuritic chest pain, friction rub, typical electrocardiographic changes, or pericardial effusion within 3 months after the ablation procedure.

RESULTS

Of 1,540 patients who underwent AF ablation, 57 patients (3.7%) developed acute pericarditis. Baseline clinical characteristics including age, sex, and body mass index were comparable between the pericarditis and nonpericarditis groups. The median time to symptom onset was 1 day. Electrocardiographic changes were observed in 34 (59.6%) patients, pericardial effusion developed in 7 (12%) patients, and the mean duration of medical treatment was 7 days (25th-75th percentile: 3-14 days). Most pericarditis cases were treated medically with disease-specific nonsteroidal anti-inflammatory drugs (100%) and colchicine (81%). Effusion with tamponade necessitating pericardiocentesis was observed in 4 (7%) patients. Radiofrequency (RF) ablation was performed in 869 (58.6%) patients in the nonpericarditis group and 39 (68.4%) patients with pericarditis; cryoballoon ablation was performed in 486 (32.8%) patients in the nonpericarditis group and 11 (19.3%) patients with pericarditis. Multivariable logistic regression analysis identified RF ablation (OR: 2.09; 95% CI: 1.07-4.08; P = 0.03) as an independent predictor of acute pericarditis after AF ablation, whereas age per unit increase was associated with a decreased risk (OR: 0.97; 95% CI: 0.95-0.995; P = 0.02).

CONCLUSIONS

The incidence of acute pericarditis after catheter ablation in our study population was 3.7%. RF ablation and younger age were independent risk factors for postablation acute pericarditis.

Long-term efficacy and safety of cryoballoon ablation of atrial fibrillation: A systematic review and meta-analysis

BACKGROUND

This meta-analysis evaluated long-term efficacy and safety of cryoballoon ablation (CB) of atrial fibrillation (AF).

METHODS

PubMed, Cochrane Library, and Web of Science were searched until July 31, 2023, for published works investigating efficacy and safety of CB of AF in which mean/median follow-up time was not less than 36 months. Safety was assessed by adverse events. Efficacy was assessed by AF recurrence, defined as any atrial arrhythmias lasting more than 30 s.

RESULTS

A total of 19 clinical studies were included. After an average of 58.1 months of follow-up, the overall AF recurrence rate was about 37%. The predictors of recurrence were duration of AF (HR 1.00; 95% CI [1.00 ∼ 1.01]), early recurrence of atrial fibrillation (HR 3.96; 95%CI [1.12 ∼ 14.02]), left atrial diameter (HR 1.04; 95%CI [1.02 ∼ 1.06]), and persistent AF (HR1.47; 95% CI [1.19 ∼ 1.82]). In terms of safety, the incidence of transient phrenic paralysis (PNP) was the highest, about 3%; followed by vascular complications (about 2%); pseudoaneurysm, permanent PNP, and all-cause death was (about 1%); and pericardial effusion and stroke / TIA was very low.

CONCLUSION

CB is associated with low rates of severe complications and reasonable success rates.

Acute procedural efficacy and safety of a novel expandable diameter cryoballoon in atrial fibrillation ablation: Early results from a multicenter ablation registry

INTRODUCTION

The major limitation of the current cryoballoon (CB) system is a fixed 28 mm balloon-size. We sought to analyze real-world early experience with novel-sized adjustable CB.

METHODS

This multicenter observational study included 140 consecutive atrial fibrillation patients (71 years, 94 men, 86 paroxysmal) who underwent pulmonary vein (PV) isolation using expandable diameter CB capable of ablation at 28 or 31 mm.

RESULTS

Out of 544 targeted PVs, 526 (96.7%) were successfully isolated by a size-adjustable CB with a 770 [690-870] second median application dose, while the remaining 18 required touch-up ablation. Among them, 326 (62.0%) PVs were isolated by a 31 mm balloon, and the rate was significantly higher for upper than lower PVs (73.0% vs. 45.7%, p < .0001) and highest for right superior (78.5%) and lowest for right inferior (39.9%) PVs. The biophysical parameters and time to isolation were comparable between the 28 and 31 mm balloons, however, the real-time PV potential monitoring capability was significantly higher for 31 mm than 28 mm balloons for the left superior PV. The esophageal temperature reached 15°C during left inferior PV ablation significantly more often with 31 mm than 28 mm balloons (43.1% vs. 18.2%, p = .008). Right phrenic nerve injury (PNI) occurred in 9 (6.4%) patients during applications (6 right superior, 2 right inferior PVs), and most occurred with a 31 mm balloon.

CONCLUSIONS

Our real-world early data demonstrated high acute efficacy and safety of the novel-sized adjustable CB. The biophysical parameters were similar between the 28 and 31 mm balloons. No marked decrease in the incidence of PNI was observed even with 31 mm balloons.

Progress in atrial fibrillation ablation during 25 years of Europace journal

The first edition of Europace journal in 1999 came right around the time of the landmark publication of the electrophysiologists from Bordeaux, establishing how elimination of ectopic activity from the pulmonary veins (PVs) resulted in a marked reduction of atrial fibrillation (AF). The past 25 years have seen an incredible surge in scientific interest to develop new catheters and energy sources to optimize durability and safety of ablation, as well as study the mechanisms for AF and devise ablation strategies. While ablation in the beginning was performed with classic 4 mm tip catheters that emitted radiofrequency (RF) energy to create tissue lesions, this evolved to using irrigation and contact force (CF) measurement while increasing power. Also, so-called single-shot devices were developed with balloons and arrays to create larger contiguous lesions, and energy sources changed from RF current to cryogenic ablation and more recently pulsed field ablation with electrical current. Although PV ablation has remained the basis for every AF ablation, it was soon recognized that this was not enough to cure all patients, especially those with non-paroxysmal AF. Standardized approaches for additional ablation targets have been used but have not been satisfactory in all patients so far. This led to highly technical mapping systems that are meant to unravel the drivers for the maintenance of AF. In the following sections, the development of energies, strategies, and tools is described with a focus on the contribution of Europace to publish the outcomes of studies that were done during the past 25 years.

Ablation as First-line Therapy for Atrial Fibrillation

AF is a chronic and progressive heart rhythm disorder characterised by exacerbations and remissions. Contemporary guidelines recommend antiarrhythmic drugs (AADs) as the initial therapy for the maintenance of sinus rhythm. However, these medications have modest efficacy and are associated with significant adverse effects. Several recent trials have evaluated catheter ablation as an initial therapy for AF, demonstrating that cryoballoon catheter ablation significantly improves arrhythmia outcomes (e.g. atrial tachyarrhythmia recurrence and arrhythmia burden), produces clinically meaningful improvements in patient-reported outcomes (e.g. symptoms and quality of life), and significantly decreases healthcare resource usage (e.g. hospitalisation), without increasing the risk of serious adverse events. Moreover, in contrast to antiarrhythmic drugs, catheter ablation appears to be disease-modifying, significantly reducing the progression of disease. These findings are relevant to patients, providers, and healthcare systems, helping inform the initial choice of rhythm-control therapy in patients with treatment-naïve AF.

Safety of a single bolus administration of heparin without the measurement of activated clotting time during cryoballoon ablation: a prospective randomized controlled trial

BACKGROUND

Single-shot ablation has emerged as an effective technique for index atrial fibrillation (AF) ablation, with an advantage of short procedure time. Although recent guidelines recommend peri-procedural uninterrupted oral anticoagulants (OACs), the intra-procedural anticoagulation strategy remains uncertain under non-vitamin K OACs (NOACs). We investigated procedural safety of a single bolus administration of heparin without activated clotting time (ACT) measurement during cryoballoon ablation (CBA).

METHODS

Two hundred patients (64.2 ± 10.0 years, 70% with non-paroxysmal AF) who underwent CBA with uninterrupted NOACs were randomly assigned to No-ACT group and ACT group. A bolus of heparin (100 U/kg) was routinely administered immediately after transseptal puncture. In the ACT group, an additional injection of heparin (30 U/kg) was administered if ACT at 30 min after the initial bolus was < 300 s.

RESULTS

There were no differences in baseline characteristics including CHA₂DS₂-VASc score between the two groups. The left atrium indwelling and procedure times were 60.4 ± 13.1 min and 78.9 ± 13.9 min, respectively, and not significantly different between the two groups. The mean ACT was 335.2 ± 59.9 s in the ACT group. Any bleeding rate was 3.2% in all patients and there was no statistically significant difference in bleeding complications between the two groups. In the ACT group, groin hematoma, laryngopharyngeal bleeding, and hemoptysis occurred in 3, 1, and 1 patient, respectively. Cardiac tamponade occurred in 1 patient in the No-ACT group. No thromboembolic events occurred during the 30-day follow-up after CBA.

CONCLUSIONS

Single bolus administration of heparin without ACT measurement is a feasible anticoagulation strategy for CBA in patients with uninterrupted NOAC intake.

Efficacy of Catheter Ablation for Atrial Fibrillation in Hypertrophic Cardiomyopathy: A Systematic Review and Meta-Analysis

Atrial fibrillation (AF) is the most common arrhythmia in patients with hypertrophic cardiomyopathy (HCM). Catheter ablation (CA) has emerged as an effective therapy for AF. We conducted a meta-analysis to update the current clinical evidence on the efficacy of CA for AF in patients with HCM. We searched PubMed, Embase, Cochrane and Clinicaltrials.gov for interventional and observational studies assessing single and multiple procedure success rate of CA in HCM patients. Our meta-analysis included 25 studies involving 1817 patients. Success rate following single procedure was 40.4% (95% CI 33.1 to 48.0%) at latest follow-up. The pooled success rate following multiple procedures was 51.4% (95% CI 42.9% to 60.0%) at latest follow-up. In the subgroup analysis for AF subtype, TCA was more successful for paroxysmal AF compared to non-paroxysmal AF. For the subset of studies reporting drug-free success rate, single and multiple procedures had a success rate of 33.4% (95% CI 19.3 to 49.1%) and 51.8% (95% CI 41.3 to 62.2%) at latest follow-up, respectively. CA is a suitable option for AF in patients with HCM. Success rate is greater in paroxysmal AF, after multiple procedures and with antiarrhythmic drugs.

Impact of Low Body Mass Index on Cardiac Tamponade During Catheter Ablation for Atrial Fibrillation

BACKGROUND

Cardiac tamponade is a potentially fatal complication of catheter ablation for atrial fibrillation (AF).

OBJECTIVES

This study aimed to evaluate the impact of body mass index (BMI) on cardiac tamponade during AF ablation.

METHODS

Patients who underwent catheter ablation for AF between April 1, 2016 and March 31, 2018 were analyzed using a Japanese nationwide claims database. Mixed-effects multivariable Poisson regression analysis was performed to investigate the association between BMI and cardiac tamponade.

RESULTS

A total of 59,789 hospitalizations (age 65.6 ± 10.4 years, 29% women) with catheter ablation for AF were analyzed. Cardiac tamponade occurred in 647 patients (1.1%). Multivariable analysis revealed that being underweight (BMI <18.5 kg/m²) was associated with an increased risk of cardiac tamponade (relative risk [RR]: 1.42; 95% CI: 1.03-1.95) when compared with having a normal weight (BMI ≥18.5 and <25 kg/m²). Other characteristics that were associated with an increased risk of cardiac tamponade were age ≥75 years, female sex, and a history of heart failure, hypertension, diabetes, and dialysis treatment.

CONCLUSIONS

In this analysis of a large nationwide database of patients with AF who underwent ablation, being underweight was independently associated with an increased risk of cardiac tamponade during AF ablation. Clinicians should consider the higher risk of cardiac tamponade in the underweight population and take appropriate measures to reduce this risk.

Evaluation of Isolation Area, Myocardial Injury and Left Atrial Function Following High-Power Short-Duration Radiofrequency or Second-Generation Cryoballoon Ablation for Atrial Fibrillation

This randomized study aims to compare the left atrial (LA) lesion size, function, and tissue damage following pulmonary vein isolation (PVI) by high-power short-duration (HPSD) radiofrequency (RF) and second-generation cryoballoon (CB2) ablation. We enrolled 40 patients with paroxysmal atrial fibrillation who underwent PVI by HPSD RF (n = 21) or CB2 (n = 19). Every patient underwent LA CT angiography and transthoracic echocardiography (TTE) to assess the LA anatomy and function. Biomarker levels (hs-cTnT, hs-CRP, LDH) were compared pre- and post-procedurally. Pre- and post-ablation high-density mapping (HDM) was performed. The isolation area was defined under 0.2 mV bipolar voltage (low voltage area, LVA). We calculated the post-PVI LVA/LA surface ratio using LA CT-HDM merge images. At 3-month follow-up, TTE was performed to assess the changes in LA function. Post-ablation hs-cTnT level was significantly higher in the RF group (RF: 1249 ± 469 ng/L, CB2: 995 ± 280 ng/L, p = 0.024). Post-PVI hs-CRP (RF: 9.53 ± 10.30 mg/L, CB2: 12.36 ± 5.76 mg/L, p = 0.034) and LDH levels (RF: 349.9 ± 65.6 U/L, CB2: 451.6 ± 91.3 U/L, p < 0.001) were significantly higher following CB2 ablation. Post-PVI LVA/LA surface ratios were 8.37 ± 6.42% in the RF group and 13.58 ± 8.92% in the CB2 group (p = 0.022). LA function did not change significantly after the PVI procedure. Our data indicate that second-generation cryoballoon ablation produces a significantly larger LA lesion size compared to “point-by-point” HPSD radiofrequency. Both techniques preserve LA function. The myocardial component of tissue loss appears to be higher using HPSD radiofrequency ablation, with less collateral damage.

Cryoablation as a first-line therapy for atrial fibrillation: current status and future prospects

INTRODUCTION

Atrial fibrillation (AF) is a common chronic and progressive heart rhythm disorder. For those in whom sinus rhythm is desired, contemporary clinical practice guidelines recommend antiarrhythmic drugs (AADs) as the initial therapy. However, these medications have modest efficacy and are associated with significant adverse effects.

AREAS COVERED

The current article reviews the evidence surrounding first line catheter ablation, particularly the emerging evidence surrounding the use of cryoballoon ablation as a first-line therapy. The focus of the review is on the outcomes of arrhythmia freedom, quality of life, healthcare utilisation and safety. In addition, the article will review novel cryoablation systems.

EXPERT OPINION

: Recent evidence suggests that cryoballoon ablation significantly improves arrhythmia outcomes (e.g., freedom from any atrial tachyarrhythmia or symptomatic atrial tachyarrhythmia, reduction in arrhythmia burden), patient-reported outcomes (e.g., symptoms and quality of life), and healthcare resource utilization (e.g., hospitalization), without increasing the risk of adverse events. These findings are relevant to patients, providers, and healthcare systems, as it helps inform the decision-making regarding the initial choice of rhythm-control therapy in patients with treatment-naïve AF.

New evidence: Cryoballoon ablation vs. antiarrhythmic drugs for first-line therapy of atrial fibrillation

Atrial fibrillation (AF) is a commonly encountered chronic and progressive heart rhythm disorder, characterized by exacerbations and remissions. Contemporary clinical practice guidelines recommend a trial of antiarrhythmic drugs (AADs) as the initial therapy for sinus rhythm maintenance; however, these medications have modest efficacy and are associated with significant adverse effects. Recently, several trials have demonstrated that an initial treatment strategy of cryoballoon catheter ablation significantly improves arrhythmia outcomes (e.g. freedom atrial tachyarrhythmia and reduction in arrhythmia burden), produces clinically meaningful improvements in patient-reported outcomes (e.g. symptoms and quality of life), and significantly reduces subsequent healthcare resource utilization (e.g. hospitalization), without increasing the risk of serious or any adverse events. These findings are relevant to patients, providers, and healthcare systems, helping inform the decision regarding the initial choice of rhythm-control therapy in patients with treatment-naïve AF.

Ten-year trends in mortality and complications following catheter ablation of atrial fibrillation

AIMS

Recent US studies report rising rates of mortality and in-hospital complications following catheter ablation of atrial fibrillation (AF), but whether this is a global phenomenon is uncertain. The aim of this study was to examine trends in 30-day mortality and complications following AF ablation in Australia and New Zealand (ANZ) from 2008 to 2017.

METHODS AND RESULTS

We identified 37 243 AF (mean age 62.4 ± 11.5 years, 29.6% females, 94.5% elective procedures) ablations using national hospitalization data. The primary outcome was occurrence of any complication, including all-cause mortality, within 30 days of discharge. Trends were evaluated using logistic regression adjusting for changes in patient characteristics. The annual number of ablations increased from 1359 (2008) to 5115 (2017). Patients' age and rates of heart failure (9.8-10.6%), diabetes (6.8-12.4%), and chronic kidney disease (2.2-4.1%) also increased over time. From 2008 to 2017, the overall rate of complications declined from 7.51% to 5.04% [adjusted odds ratio (aOR) 0.96 (95% confidence interval, CI, 0.94-0.97)/year]. Rates of pericardial effusion [1.69-0.70%, aOR 0.93 (0.89-0.97)], bleeding [4.49-2.74%, aOR 0.94 (0.92-0.96)], and vascular injury [0.52-0.16%, aOR 0.91 (0.85-0.98)] declined, but rates of acute kidney injury [0.15-0.68%, aOR 1.16 (1.08-1.25)] and infection [0.15-0.57%, aOR 1.07 (1.01-1.14)] increased over time. The overall 30-day mortality rate was low (0.11%) and unchanged [0.00-0.16%, aOR 0.99 (0.88-1.11)].

CONCLUSION

Despite a five-fold increase in AF ablations and the rising risk profile of patients, complications following AF ablation declined by 30% from 2008 to 2017 in ANZ. Procedure-related death was uncommon and occurred in less than 1 in 850 patients.

Long-Term Cost-Effectiveness Comparison of Catheter Ablation and Antiarrhythmic Drugs in Atrial Fibrillation Treatment Using Discrete Event Simulation

OBJECTIVES

To evaluate the lifetime cost-effectiveness of 3 widely used atrial fibrillation (AF) treatments from the perspectives of Chinese healthcare system: antiarrhythmic drugs (AADs), ThermoCool SmartTouch guided by ablation index (STAI), and second-generation cryoballoon (CB2).

METHODS

A discrete event simulation (DES) model was implemented to compare the lifetime cost-effectiveness of AADs, STAI, and CB2. AF disease progression was explicitly modeled based on the Atrial Fibrillation Progression Trial clinical study results. The base-case analysis assumed that patients with paroxysmal AF (PAF) entered the model at the age of 55 years and had a CHA2DS2-VASc (Congestive heart failure, Hypertension, Age ( > 65 = 1 point, > 75 = 2 points), Diabetes, previous Stroke/transient ischemic attack (2 points)-Vascular disease (peripheral arterial disease, previous myocardial infarction, aortic atheroma), Age 65 to 74 years, and Sex category) score of 2 for males and 3 for females. Model parameter uncertainties were incorporated throughout the DES simulation with full probabilistic model parameterization.

RESULTS

The lifetime cost-effectiveness evaluations showed that patients treated with AADs gained an average of 4.98 quality-adjusted life-years (QALYs) and 9.63 life-years (LYs) at an average cost of US dollar (USD) 15 374. Patients treated with CB2 gained 5.92 QALYs and 10.74 LYs at an average cost of USD 26 811. The STAI group gained an average of 6.55 QALYs and 11.57 LYs at an average cost of USD 24 722. The incremental cost-effectiveness ratios was USD 5927 and USD 12 167 per QALY for STAI versus AADs and CB2 versus AADs, respectively. Assuming the willingness-to-pay threshold for China is USD 30 390 per QALY, both ablation treatments will be cost-effective compared with AADs for patients with PAF.

CONCLUSIONS

The DES model demonstrated that catheter ablations are more cost-effective than AADs for patients with PAF under the healthcare system in China. Among catheter ablation technologies, STAI provides better outcomes at lower costs.

Ablação por Cateter é Superior a Drogas Antiarrítmicas como Tratamento de primeira linha para Fibrilação Atrial: uma Revisão Sistemática e Metanálise

Fundamento

A ablação por cateter é uma terapia bem estabelecida para controle do ritmo cardíaco em pacientes refratários ou intolerantes a drogas antiarrítmicas (DAA). Porém, a eficácia desse procedimento comparada à de DAA como estratégia de primeira linha no controle do ritmo cardíaco na fibrilação atrial é menos conhecida.

Objetivos

Conduzir uma revisão sistemática e metanálise da ablação por cateter vs. DAA em pacientes sem nenhum tratamento prévio para controle do ritmo.

Métodos

Buscamos, nos bancos de dados do PubMed, EMBASE, e Cochrane, ensaios randomizados controlados que compararam ablação por cateter com DAA para controle do ritmo cardíaco em pacientes com FA sintomática e descreveram os seguintes desfechos: (1) recorrência de taquiarritmia atrial (TA); (2) FA sintomática; (3) internações hospitalares; e (4) bradicardia sintomática. A heterogeneidade foi avaliada por estatística I². Valores de p menores que 0,05 foram considerados estatisticamente significativos.

Resultados

Incluímos cinco ensaios com 994 pacientes, dos quais 502 (50,5%) foram submetidos à ablação por cateter. O período médio de acompanhamento foi de um a cinco anos. Recorrências de TA (OR 0,36; IC95% 0,25-0,52; p<0,001) e de FA sintomática (OR 0,32; IC95% 0,18-0,57; p<0,001), e internações hospitalares (OR 0,25; IC95% 0,15-0,42; p<0,001) foram menos frequentes nos pacientes tratados com ablação por cateter que naqueles tratados com DAA. Bradicardia sintomática não foi diferente entre os grupos (OR 0,55; IC95% 0,18-1,65; p=0,28). Derrame ou tamponamento pericárdico significativo ocorreu em oito dos 464 (1,7%) pacientes no grupo submetido à ablação.

Conclusão

Esses achados sugerem maior eficácia da ablação por cateter que das DAA como estratégia inicial de controle do ritmo cardíaco em pacientes com DA sintomática.

Cryoablation or Drug Therapy for Initial Treatment of Atrial Fibrillation

AF is a common chronic and progressive disorder. Without treatment, AF will recur in up to 75% of patients within a year of their index diagnosis. Antiarrhythmic drugs (AADs) have been proven to be more effective than placebo at maintaining sinus rhythm and remain the recommended initial therapeutic option for AF. However, the emergence of ‘single-shot’ AF ablation toolsets, which have enabled enhanced procedural standardisation and consistent outcomes with low rates of complications, has led to renewed interest in determining whether first-line catheter ablation may improve outcomes. The recently published EARLY-AF trial evaluated the role of initial cryoballoon ablation versus guideline-directed AAD therapy. Compared to AADs, an initial treatment cryoballoon ablation strategy resulted in greater freedom from atrial tachyarrhythmia, superior reduction in AF burden, greater improvement in quality of life and lower healthcare resource utilisation. These findings are relevant to patients, providers and healthcare systems when considering the initial treatment choice for rhythm-control therapy.

[Hypotension after catheter ablation]

A 80-year-old female patient with symptomatic atrial tachycardia develops cold sweat and hypotension in the recovery room after pulmonary vein isolation. The procedure included an anterior line and an endo- and epicardial mitral isthmus line. Echocardiography excluded a hemodynamically relevant pericardial effusion. The patient's symptoms deteriorated over time. A rare cause was found.

Cryoballoon Ablation as Initial Treatment for Atrial Fibrillation: JACC State-of-the-Art Review

Atrial fibrillation (AF), the most common sustained arrhythmia observed in clinical practice, is a chronic and progressive disorder characterized by exacerbations and remissions. Guidelines recommend antiarrhythmic drugs as the initial therapy for the maintenance of sinus rhythm; however, antiarrhythmic drugs have modest efficacy to maintain sinus rhythm and can be associated with significant adverse effects. An initial treatment strategy of cryoballoon catheter ablation in patients with treatment-naïve AF has been shown to significantly improve arrhythmia outcomes (freedom from any, or symptomatic atrial tachyarrhythmia), produce clinically meaningful improvements in patient-reported outcomes (symptoms and quality of life), and significantly reduce subsequent health care resource use (hospitalization), and it does not increase the risk of serious or any adverse events compared with initial antiarrhythmic drug therapy. These findings are relevant to inform patients, providers, and health care systems regarding the initial choice of rhythm-control therapy in patients with treatment-naïve AF.

Distance between the descending aorta and the left inferior pulmonary vein as a determinant of biophysical parameters during paroxysmal atrial fibrillation cryoablation

INTRODUCTION

The distance from the descending aorta (DA) to the posterior wall of the left atrium (LA) is variable. We aimed to determine whether the proximity between the DA and the left inferior pulmonary vein (LIPV) ostium has an impact on biophysical parameters and cryoballoon (CB) ablation efficacy during LIPV freezing.

METHODS

Patients referred for CB-ablation of atrial fibrillation (AF) in two high-volume centers were included. Cryoablation data were collected prospectively for each patient. The anatomical relationships between the LIPV and the DA (distance LIPV ostium-DA, presence of an aortic imprint on the posterior aspect of the LIPV) were then retrospectively analysed on the LA computed tomography scans realized before AF ablation.

RESULTS

A total of 350 patients were included (70% men, 59.7 ± 11.5 years). The decrease in the Ostium-DA distance was significantly correlated to the increase in the time-to-isolation (TTI) (r = -.31; p = .036), with less negative temperature (r = -.11; p = .045). Similarly, the presence of an aortic imprint on the LIPV was associated with a longer TTI (p < .001). The analysis of redo procedures data shows a trend toward the presence of shorter ostium-DA distances (15.3 ± 3.29 vs. 18.1 ± 4.99, p = .15) and more frequent aortic imprints (63.6% vs. 47.5%, p = .34) in patients with LIPV reconnection as opposed to patients without reconnection in the LIPV.

CONCLUSION

Our findings indicated that the DA seems to have a "radiator" effect influencing LIPV cryoablation parameters during CB-ablation. Additional studies will be needed to elucidate whether this biophysical influence has a clinical impact in LIPVs reconnections.

Quality of life outcomes in cryoablation of atrial fibrillation-A literature review

BACKGROUND

Cryoballoon ablation (CRYO) for pulmonary vein isolation (PVI) in atrial fibrillation (AF) has become an established treatment option as alternative for radiofrequency catheter ablation (RFCA). As symptom relief is still the main indication for PVI, quality of life (QoL) is a key outcome parameter. This review summarizes the evidence about the evolution of QoL after CRYO.

METHODS

A search for clinical studies reporting QoL outcomes after CRYO was performed on PUBMED and COCHRANE. A total of 506 publications were screened and 10 studies met the in- and exclusion criteria.

RESULTS

All studies considered QoL as a secondary endpoint and reported significant improvement in QoL between baseline and 12 months follow-up, independent of the QoL instruments used. The effect size of CRYO on QoL was comparable between studies and present in both paroxysmal and persistent AF. Direct comparison between CRYO and RFCA was limited to two studies, there was no difference between ablation modalities after 12 months FU. Two studies in paroxysmal AF reported outcome beyond 12 months follow-up and QoL improvement was maintained up to 36 months after ablation. There were no long-term data available for persistent AF.

CONCLUSION

CRYO of AF significantly improves QoL. The scarce amount of data with direct comparison between subgroups limits further exploration. Assessment of QoL should be considered a primary outcome parameter in future trials with long-term follow-up.

Concomitant epicardial left atrial appendage ligation and left atrial ablation of atrial fibrillation: Safety, feasibility and outcome

Introduction

We present initial results of patients undergoing a combined procedure of epicardial LAA ligation in addition to left atrial ablation for AF.

Methods

9 patients were included for additional use of LARIAT as an individual treatment approach for AF. First an epicardial LAA ligation was performed, in the same procedure left atrial ablations consisting of PVI and additional substrate based modifying ablations were performed. Follow–up at 3 months and 12 months was performed.

Results

There was only 1 minor procedural complication (11%) involving epicardial bleeding and 2 late adverse events of pericardial tamponade and stroke. At the final follow-up (median 20 months) 7 patients were in stable sinus rhythm (78%) and 2 pts had reduced AF burden.

Conclusion

Concomitant epicardial LAA ligation and ablation is feasible in selected patients with a reasonable risk profile. More prospective data are required to validate the safety and efficacy.

Cryoballoon vs radiofrequency ablation of atrial fibrillation: insights from the Veterans Healthcare System

PURPOSE

Catheter ablation is considered the mainstay treatment for drug-refractory atrial fibrillation (AF). The aims of our study were to compare the efficacy and safety of the most two currently approved approaches (point-by-point radiofrequency ablation (RFA), either with contact force (CF) or without contact force (nCF) catheters, and cryoballoon ablation (CBA)) in the Veterans Healthcare System.

METHODS

We performed a retrospective study of patients who underwent ablation for treatment of AF at the veterans affairs healthcare system between 2013 and 2018. Only the first reported ablation procedure was included.

RESULTS

We included 956 patients in the study (97.4% males, 91.5% Caucasians, 67% paroxysmal AF), with 682 patients in RFA-nCF, 139 in RFA-CF, and 135 in CBA. Thirty-day complication rates were comparable between the three groups with the exception of higher incidence of phrenic nerve injury in CBA group when compared to RFA-nCF (2.2% vs 0.0%, p < 0.01). Long-term recurrence rate of AF was significantly lower in the CBA group when compared to RFA-nCF (33.3% vs 47.7%, adjusted HR 0.60, 95% CI 0.44-0.83, p < 0.01). On the other hand, it was similar between RFA-CF and RFA-nCF groups (43.9% vs 47.7%, adjusted HR 1.01, 95% CI 0.76-1.33, p 0.97). After stratifying patients based on AF type, these findings were only present in patients with paroxysmal AF.

CONCLUSION

CBA for paroxysmal AF, in male dominant patients' population, was associated with lower incidence of AF recurrence rate while having a comparable safety profile to RFA independent of the use of CF catheters.

Increasing role of cardiac surgeons in managing cardiac perforations during ever-expanding percutaneous interventions: a mini-review

Iatrogenic cardiac injury is a catastrophic event and its management should be emergent. Cardiac surgeons need to be aware of basics related to the catheter-based intervention techniques and their outcomes. This mini-review discusses cardiac perforations and role of surgical team during catheter-based interventions.

From electrophysiological exploration to management of heart arrhythmias: Economic analysis of practices in a high-volume French hospital over two different time periods

BACKGROUND

Medical devices (MD) used to treat arrhythmias range from electrophysiological exploration catheters to intracardiac ablation catheters, and they are continuously undergoing optimization. The inclusion of innovative MD in Diagnosis Related Groups (DRG) of the French healthcare economic system can lead to financial imbalance for health institutions. The objective of this study was to compare cost-revenue analyses for interventional heart rhythm management in a high-volume French hospital between two time periods.

METHODS

For 3 months in 2014 and 3 months in 2017, all of the patients admitted to the interventional rhythmic unit with arrhythmia were included retrospectively in this monocenter study. All arrhythmias were considered. The primary clinical endpoint was the difference between the expenses and incomes, calculated for each patient. The secondary endpoint was the breakdown of costs.

RESULTS

217 patients were included. In 2014 period, the analysis revealed a deficit of 409±1717 euros per patient and an overall deficit for the hospital of 44,635 euros. In 2017 period, the same evaluation indicated a deficit of 446±1316 euros per patient and an overall deficit for the hospital of 48,210 euros. The cost of MD accounts for a significant share of total expenses.

CONCLUSION

The profitability for the cardiac rhythm activity at our facility was optimized between 2014 and 2017. The reliance on ambulatory care increased. However, the reduction in the expenses incurred did not increase the profitability for the facility. It was offset by a decrease in DRG tariffs. A flowchart-type structure based on these practices analyses for rhythmic disorder treatments was developed.

A prospective multicenter study of direct comparison of feasibility and safety of pulmonary vein isolation using the minimally interrupted apixaban between second-generation cryoballoon and radiofrequency ablation of paroxysmal atrial fibrillation: J-HIT apixaban

BACKGROUND

The feasibility and safety of pulmonary vein isolation (PVI) using cryoballoon (CB) for paroxysmal atrial fibrillation (PAF) with minimally interrupted apixaban has not fully explored.

METHODS

In this multicenter, randomized prospective study, we enrolled patients with PAF undergoing CB or radiofrequency (RF) ablation with interrupted (holding 1 dose) apixaban. The primary composite end point consisted of bleeding events, including pericardial effusion and major bleeding requiring blood transfusion, or thromboembolic events at 4 weeks after ablation; secondary end points included early recurrence of AF and procedural duration.

RESULTS

A total of 250 patients underwent PVI (125 assigned to the RF ablation and 125 assigned to the CB ablation). The primary end point occurred in 1 patient in the CB ablation group (0.8%; 90% confidence interval [CI], 0.04 to 3.70) and 3 patients in the RF group (2.4%, P = .622; risk ratio, 0333; 90% CI, 0.05 to 2.20). All events were pericardial effusion, all of whom recovered after pericardiocentesis. Early recurrence of AF occurred in 4 patients (3.2%) in the RF group and in 6 patients (4.8%) in the CB group (P = .749). The procedural duration was shorter in the CB group than that in the RF group (136.5 ± 39.9 vs 179.5 ± 44.8 min, P < .001).

CONCLUSION

CB ablation with minimally interrupted apixaban was feasible and safe in patients with PAF undergoing PVI, which was equivalent to RF ablation.

A systematic review and meta-analysis comparing second-generation cryoballoon and contact force radiofrequency ablation for initial ablation of paroxysmal and persistent atrial fibrillation

INTRODUCTION

Cryoballoon ablation (CBA) and radiofrequency ablation (RFA) are the preferred modalities for catheter ablation of atrial fibrillation (AF). Technological advances have improved procedural outcomes, warranting an updated comparison. We sought to evaluate the efficacy and safety of CBA-2nd generation (CBA-2G) in comparison to RFA-contact force (RFA-CF) in patients with AF.

METHODS

MEDLINE, Cochrane, and ClinicalTrials.gov databases were searched until 03/01/2020 for relevant studies comparing CBA-2G versus RFA-CF in patients undergoing initial catheter ablation for AF.

RESULTS

A total of 17 studies, involving 11 793 patients were included. There was no difference between the two groups in the outcomes of freedom from atrial arrhythmia (p = .67) and total procedural complications (p = .65). There was a higher incidence of phrenic nerve palsy in CBA-2G (odds ratio: 10.7; 95% confidence interval [CI]: 5.85 to 19.55; p < .001). Procedure duration was shorter (mean difference: -31.32 min; 95% CI: -40.73 to -21.92; p < .001) and fluoroscopy duration was longer (+3.21 min; 95% CI: 1.09 to 5.33; p = .003) in CBA-2G compared to RFA-CF. In the subgroup analyses of patients with persistent AF and >1 freeze lesion delivered per vein, there was no difference in freedom from atrial arrhythmia.

CONCLUSIONS

In AF patients undergoing initial ablation, CBA-2G and RFA-CF were equally efficacious. The procedure duration was shorter, but with a higher incidence of phrenic nerve palsy in CBA-2G. In patients with persistent AF, there was no difference in the efficacy between CBA-2G or RFA-CF techniques.

Atrial fibrillation ablation in heart failure patients: improved systolic function after cryoballoon pulmonary vein isolation

Aims

Atrial fibrillation (AF) and heart failure (HF) are the most common cardiac diseases and often coexist leading to increased mortality and morbidity compared with AF patients without HF. As shown previously, AF ablation using radio frequency (RF) in HF patients leads to a reduction of AF burden, an increase of left ventricular ejection fraction (LVEF) and consequently to reduced hospitalization and mortality. Previous AF ablation studies on HF patients have been liberal about additional targets beyond pulmonary vein isolation (PVI). Thus, the aim of this study was to assess systematically the impact of a straightforward PVI‐only strategy on LVEF, NYHA functional class, and cardiovascular hospitalization rate in HF patients.

Methods and results

Out of 414 consecutive patients undergoing PVI, only with the cryoballoon 113 patients with reduced LVEF [mean: 38.4 ± 10.8%, reduced ejection fraction (rEF) group] and 301 patients with normal LVEF (>55%) at baseline were identified [normal ejection fraction (nEF) group]. Remarkably, even though freedom from arrhythmia recurrence after 1 year was significantly lower in the rEF group (64.9%) compared with the nEF group (71.2%, P = 0.036), mean LVEF improved from 38.4 ± 10.8% to 52.5 ± 17.2% (P < 0.001) after cryoballoon ablation in the rEF group. Accordingly, HF‐related symptoms as well as hospitalization rate declined significantly in the rEF group during follow‐up compared with baseline.

Conclusions

The results of the present study suggest that catheter ablation restricted to a straightforward PVI‐only strategy using the cryoballoon leads to improved left ventricular ejection fraction as well as improvement of NYHA functional class and increased freedom from cardiovascular rehospitalization.

The Cryoballoon vs Irrigated Radiofrequency Catheter Ablation (CIRCA-DOSE) Study Results in Context

The Cryoballoon vs Irrigated Radiofrequency Catheter Ablation: Double Short vs Standard Exposure Duration (CIRCA-DOSE) study was a multicentre, randomised, single-blinded trial that compared contact-force radiofrequency ablation and two different regimens of cryoballoon ablation. All patients received an implantable cardiac monitor for the purpose of continuous rhythm monitoring, with all arrhythmia events undergoing independent adjudication by a committee blinded to treatment allocation. The study demonstrated there were no significant differences between contact-force radiofrequency ablation and cryoballoon ablation with respect to recurrence of any atrial tachyarrhythmia, symptomatic atrial tachyarrhythmia, asymptomatic AF, symptomatic AF or AF burden. While the results of the CIRCA-DOSE study are reviewed here, this article focuses on considerations around the design of the study and places the observed outcomes in context.

Cryoablation for atrial fibrillation

Cryoballoon ablation for the treatment of atrial fibrillation has established itself as an effective and efficient modality for achieving pulmonary vein isolation. Over the past 13 years more than 100,000 Cryoballoon ablation procedures have been performed with the first to fourth generation cryoballoons. Over that time there have been significant advances in our understanding regarding the optimal procedural techniques. The purpose of this "topic in review" is to focus on the practical aspects of performing a Cryoballoon ablation procedure, within the context of the contemporary literature. Specifically there is a focus on how contemporary studies can inform clinical decision making and ensure operators are able to perform a safe and effective procedure.

Cryoballoon ablation for pulmonary vein isolation

Over the past 20 years, multiple studies have demonstrated the superiority of percutaneous catheter-based pulmonary vein isolation (PVI) in the management of atrial fibrillation (AF). Unfortunately, the results of catheter ablation can be limited by arrhythmia recurrence, which is often a result of a failure to achieve durable lesions around the pulmonary vein ostia. In response, significant efforts have been directed toward developing technologies to achieve safer and more durable PVI, including the development of dedicated catheters capable of achieving PVI with a single ablation lesion (eg, the Arctic Front Cryoballoon; Medtronic CryoCath, Pointe-Claire, Canada). The purpose of this review is to discuss the contemporary role of cryoballoon ablation in the invasive management of AF, with a focus on the characteristics that differentiate cryoballoon from radiofrequency ablation.

Characterization of atrial flutter after pulmonary vein isolation by cryoballoon ablation

PURPOSE

Pulmonary vein isolation (PVI) by cryoballoon ablation (CBA) has emerged as a commonly used technique for the treatment of atrial fibrillation. We sought to explore the incidence, risk factors for, and characterization of post-CBA-PVI atrial flutter.

METHODS

We analyzed a prospective registry of patients who underwent CBA-PVI at a single institution. We included patients with more than 3 months of follow-up data and excluded those with a history of cavotricuspid isthmus (CTI) ablation. Locations of post-CBA-PVI atrial flutters were determined by analysis of intracardiac electrograms and electroanatomic maps.

RESULTS

There were 556 patients included in the analysis. The mean age was 61.0 ± 10.6 years, 67.4% were male, the number of failed anti-arrhythmic medication trials was 1.2 ± 0.8, and the duration of atrial fibrillation pre-CBA was 54.3 ± 69.1 months. The 28-mm second-generation cryoballoon was used almost exclusively. Over a median follow-up time of 22.7 ± 17.9 months, 25 (4.5%) patients developed post-CBA-PVI atrial flutter after the 3-month blanking period. Of those 25 patients, 15 (60%) underwent subsequent ablation to eliminate the atrial flutter circuit, with 60% being CTI-dependent and the remainder left-sided (p value not significant). Risk factors for the development of atrial flutter included NYHA class ≥ 2 (OR 5.02, p < 0.001), presence of baseline bundle branch block (OR 4.33, p = 0.006), and left ventricular ejection fraction < 50% (OR 3.36, p = 0.007).

CONCLUSIONS

The rate of post-CBA-PVI atrial flutter is low after the blanking period even with medium-term follow-up. The origin of atrial flutter is equally divided between the right and left atria.

Cryoballoon vs. radiofrequency lesions as detected by late-enhancement cardiac magnetic resonance after ablation of paroxysmal atrial fibrillation: a case-control study

AIMS

Cryoballoon (CB) ablation has emerged as a reliable modality to isolate pulmonary veins (PVs) in atrial fibrillation. Ablation lesions and the long-term effects of energy delivery can be assessed by delayed-enhancement cardiac magnetic resonance (DE-CMR). The aim of the study was to compare the number, extension, and localization of gaps in CB and radiofrequency (RF) techniques in pulmonary vein isolation (PVI).

METHODS AND RESULTS

Consecutive patients submitted to PVI with CB in whom DE-CMR images were available (n = 30) were matched (1:1) to patients who underwent PVI with RF (n = 30), considering age, sex, hypertension, and diabetes. Delayed-enhancement cardiac magnetic resonance was obtained at 3 months post-procedure, and images were processed to assess the mean number of gaps around PV ostia, their localization, and the normalized gap length (NGL), calculated as the difference between total gap length and total PV perimeter. Patients were followed up for 12 months. The CB and RF procedures did not differ in the mean number of gaps per patient (4.40 vs. 5.13 gaps, respectively; P = 0.21) nor NGL (0.35 vs. 0.32, P = 0.59). For both techniques, a higher mean number of gaps were detected in right vs. left PVs (3.18 vs. 1.58, respectively; P = 0.01). The incidence of recurrences did not differ between techniques (odds ratio 1.87, 95% confidence interval 0.66-4.97; P = 0.29).

CONCLUSION

Location and extension of ablation gaps in PVI did not differ between CB and RF groups in DE-CMR image analysis.

Cryothermal atrial linear ablation in patients with atrial fibrillation: An insight from the comparison with radiofrequency atrial linear ablation

BACKGROUND

Atrial linear lesions are generally created with radiofrequency energy. We sought to evaluate the feasibility of cryothermal atrial linear ablation.

METHODS AND RESULTS

Twenty-one atrial fibrillation (AF) patients underwent linear ablation on the left atrial (LA) roof, mitral isthmus (MI), and cavotricuspid isthmus (CTI) with 8-mm-tip cryocatheters following pulmonary vein isolation. The data were compared with those of 31 patients undergoing linear ablation with irrigated-tip radiofrequency catheters. Conduction block was successfully created in 18 of 20 (90%), 9 of 21 (43%), and 20 of 20 (100%) on the LA roof, MI, and CTI by endocardial cryoablation alone with 19.0 (12.0-24.0), 30.0 (23.0-34.0), and 14.0 (14.0-16.0) minute cryo applications, respectively. The presence of either an interposed circumflex artery or pouch at the MI was significantly associated with failed MI block (P = .04). Conduction block was created in 25 of 31 (83.9%), 27 of 31 (87.1%), and 30 of 31 (96.8%) on the roof, MI, and CTI, respectively, by radiofrequency ablation. During the 17.5 (13.0-31.7) months of follow-up, freedom from AF/atrial tachycardia (AT) was significantly higher in the cryo group (P = .05); especially, recurrent AT was more frequent in the RF group (8/31 vs 1/21; P = .03). Conduction block across the roof, MI, and CTI was durable in 6 of 12 (50.0%), 4 of 12 (33.3%), and 9 of 12 (75.0%) patients during second procedures. All nine patients (except one) with recurrent ATs had at least one roof or MI conduction resumption.

CONCLUSIONS

Cryoablation is effective for creating a roof and CTI linear block, however, creating MI block by endocardial ablation alone was often challenging. Conduction resumption of LA linear block is common and recurrent arrhythmias, especially iatrogenic ATs, are more frequently observed after radiofrequency linear ablation.

Paroxysmal atrial fibrillation recurrence after redo procedure-ablation modality impact

BACKGROUND

Atrial fibrillation recurrence (AFR) is common after pulmonary vein isolation (PVI), and the rate does not differ between radiofrequency (RF) and cryoballoon (CB) ablation. The aim of this study was to assess the impact of the ablation modality used at the index PVI on the outcome after redo PVI in patients with paroxysmal AF.

METHODS

In this prospective, single-center, non-randomized study, consecutive patients with paroxysmal AF who have undergone the index PVI with either RF ablation (RF group) or 2nd-generation CB (CB group) were included. The primary endpoint was freedom from recurrence of atrial arrhythmia lasting > 30 s.

RESULTS

A total of 105 patients undergoing redo PVI for paroxysmal AF were included (median age 61 years; 24% female; left ventricular ejection fraction (LVEF) 57 ± 8%; left atrial volume index (LAVI) 34 ± 11 mm). Index PVI was done either with focal RF (n = 81) or with CB (n = 24) and redo PVI only with focal RF. Total procedure time (139 vs. 113 min, p = 0.10) and RF delivery time (1017 vs. 870 s, p = 0.33) of the redo PVI were not significantly different. After a median follow-up of 371 (185-470) days, there were no differences between the RF and CB groups regarding the AFR rate after the second PVI (24 vs. 23%, p = 0.89). The Kaplan-Meier analysis showed no difference between the groups regarding AFR freedom time (p = 0.81). In multivariable logistic regression, only coronary artery disease was identified as an independent long-term predictor of AFR (OR 4.15, 95% CI 1.17-14.71, p = 0.027).

CONCLUSIONS

The ablation modality used at the index PVI has no impact on long-term outcome after redo PVI in patients with paroxysmal AF.

Pericardial tamponade as a complication of invasive cardiac procedures: a review of the literature

Cardiac tamponade (CT) is a rare but often life-threatening complication after invasive cardiac procedures. Some procedures favor CT. Furthermore, the incidence depends on patients’ comorbidities, sex and age and operators’ skills. In this paper we review studies and meta-analyses concerning the rate of iatrogenic CT. We define the risk factors of CT and show concise characteristics for each invasive cardiac procedure separately. According to our analysis CT occurs especially after procedures requiring transseptal puncture or perioperative anticoagulation. The overall rate of CT after such procedures varies among published studies from 0.089% to 4.8%. For this purpose we searched the PubMed database for clinical studies published up to December 2018. We included only those studies in which a defined minimum of procedures were performed (1000 for atrial fibrillation ablation, 6000 for percutaneous coronary intervention, 900 for permanent heart rhythm devices, 90 for left atrial appendage closure, 300 for transcatheter aortic valve implantation and percutaneous mitral valve repair with the Mitra-Clip system). The search was structured around the key words and variants of these terms. In addition, secondary source documents were identified by manual review of reference lists, review articles and guidelines. The search was limited to humans and adults (18+ years).

Radiofrequency versus cryoballoon ablation for atrial fibrillation: an argument for a 'cryo-first' approach

PURPOSE OF REVIEW

Radiofrequency and cryoballoon ablation are the two most common modalities for catheter ablation of atrial fibrillation. Radiofrequency, being more prevalent and having existed for a longer period, is often utilized for patients' first ablations, despite the efficiency and efficacy of the cryoballoon tool. Here we examine the advantages of the cryoballoon for its use in first-time ablation of atrial fibrillation.

RECENT FINDINGS

The FIRE & ICE trial is established as conclusive evidence of the noninferiority of cryoballoon ablation to radiofrequency ablation in terms of efficacy. Since the study, cryoballoon has evolved in both form and technique, suggesting need for repeat consideration of the advantages of cryoablation over radiofrequency ablation. The second-generation cryoballoon has led to greater efficiency in achieving permanent pulmonary vein isolation, reducing complications, and reducing procedure times.

SUMMARY

There are advantages to the use of cryoballoon which could increase success of first-time ablations, delaying need for repeat procedure and lowering overall burden on patients and the healthcare system. Cryoballoon ablation should be considered for first-time ablation in patients with paroxysmal or persistent atrial fibrillation.

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.

Cryoballoon or Radiofrequency Ablation for Atrial Fibrillation Assessed by Continuous Monitoring: A Randomized Clinical Trial

BACKGROUND

Advanced generation ablation technologies have been developed to achieve more effective pulmonary vein isolation (PVI) and minimize arrhythmia recurrence after atrial fibrillation (AF) ablation.

METHODS

We randomly assigned 346 patients with drug-refractory paroxysmal AF to contact force-guided radiofrequency ablation (CF-RF; n=115), 4-minute cryoballoon ablation (Cryo-4; n=115), or 2-minute cryoballoon ablation (Cryo-2; n=116). Follow-up was 12 months. The primary outcome was time to first documented recurrence of symptomatic or asymptomatic atrial tachyarrhythmia (AF, atrial flutter, or atrial tachycardia) between days 91 and 365 after ablation or a repeat ablation procedure at any time. Secondary end points included freedom from symptomatic arrhythmia and AF burden. All patients received an implantable loop recorder.

RESULTS

One-year freedom from atrial tachyarrhythmia defined by continuous rhythm monitoring was 53.9%, 52.2%, and 51.7% with CF-RF, Cryo-4, and Cryo-2, respectively (P=0.87). One-year freedom from symptomatic atrial tachyarrhythmia defined by continuous rhythm monitoring was 79.1%, 78.2%, and 73.3% with CF-RF, Cryo-4, and Cryo-2, respectively (P=0.26). Compared with the monitoring period before ablation, AF burden was reduced by a median of 99.3% (interquartile range, 67.8%-100.0%) with CF-RF, 99.9% (interquartile range, 65.3%-100.0%) with Cryo-4, and 98.4% (interquartile range, 56.2%-100.0%) with Cryo-2 (P=0.36). Serious adverse events occurred in 3 patients (2.6%) in the CF-RF group, 6 patients (5.3%) in the Cryo-4 group, and 7 patients (6.0%) in the Cryo-2 group, with no significant difference between groups (P=0.24). The CF-RF group had a significantly longer procedure duration but significantly shorter fluoroscopy exposure (P<0.001 vs cryoballoon groups).

CONCLUSIONS

In this multicenter, randomized, single-blinded trial, CF-RF and 2 different regimens of cryoballoon ablation resulted in no difference in 1-year efficacy, which was 53% by time to first recurrence but >98% burden reduction as assessed by continuous cardiac rhythm monitoring.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT01913522.

The challenging right inferior pulmonary vein: A systematic approach for successful cryoballoon ablation

BACKGROUND

Pulmonary vein isolation (PVI) using cryoballoon ablation is widely used for rhythm control in patients with paroxysmal atrial fibrillation. This technique has a steep learning curve, and PVI can be achieved quickly in most patients. However, the right inferior pulmonary vein (RIPV) is often challenging to occlude and isolate.

AIM

We aimed to analyse the efficacy of RIPV ablation using a systematic approach.

METHODS

Consecutive patients referred for cryoballoon ablation of paroxysmal atrial fibrillation were enrolled prospectively. A systematic approach was used for RIPV cryoablation. The primary endpoint was acute RIPV isolation during initial freeze.

RESULTS

A total of 214 patients were included. RIPV isolation during initial freeze occurred in 179 patients (82.2%). Real-time PVI could be observed in 72 patients (33.6%), whereas cryoballoon stability required pushing the Achieve™ catheter inside the RIPVs in the remaining patients. The rate of unsuccessful or aborted first freeze as a result of insufficient minimal temperature was significantly higher in patients with real-time pulmonary vein potential recording (16.7% vs. 6.3%; P=0.031). To overcome this issue and obtain both stability and real-time PVI, a dedicated "whip technique" was developed. Twelve patients (5.6%) required a redo ablation; only two of these had a reconnected RIPV.

CONCLUSIONS

A systematic approach to RIPV cryoablation can lead to a high rate of first freeze application. Operators should not struggle to visualize pulmonary vein potentials before ablation, as this may decrease cryoapplication efficacy. Thus, stability should be preferred over real-time PVI for RIPV ablation. Both stability and real-time PVI can be obtained using a "whip technique".

Atrial Fibrillation Ablation: Indications and Techniques

PURPOSE OF REVIEW

Atrial fibrillation (AF) predisposes to embolic strokes and reduced quality of life. Ablation (catheter-based or surgically performed) can be employed to promote the maintenance of sinus rhythm in a carefully selected subset of patients with AF. The goal of this review is to discuss the indications and techniques for AF ablation, as well as post-procedural outcomes.

RECENT FINDINGS

Atrial fibrillation ablation improves quality of life in patients with atrial fibrillation although no clear reduction in stroke or overall mortality has been shown. Familiarity with the indications for AF ablation is important for all cardiologists, as is having a sound understanding of the efficacy of the procedure and potential complications. Furthermore, acquiring a grasp of the different modalities of AF ablation (including percutaneous endocardial techniques and surgical ablation approaches) will help to facilitate effective and appropriate referrals.

Prognostic value of high-sensitive troponin T for predicting cardiovascular events after atrial fibrillation ablation

BACKGROUND AND OBJECTIVES

This study aimed to evaluate the utility of high-sensitive troponin T (hs-TnT) for predicting AF recurrence and major adverse cardiovascular events (MACE) after AF ablation.

METHODS AND RESULTS

A total of 227 consecutive patients with AF (mean age, 66 ± 10 years; persistent AF, n = 98) who underwent an initial ablation were enrolled. We measured hs-TnT before AF ablation and divided the patients into three groups according to the hs-TnT level: low, lesser than or equal to 0.005 µg/L (n = 54); medium, 0.006-0.013 µg/L (n = 127); and high, greater than or equal to0.014 µg/L (n = 46). We evaluated the composite endpoint of AF recurrence or MACE (including death, stroke, acute coronary syndrome, and heart failure hospitalization) after the ablation. The median hs-TnT level was 0.008 µg/L. The values of chronic kidney disease prevalence, CHA₂ DS₂ -VASc score, B-type natriuretic peptide level, and left atrial diameter were the highest in the high hs-TnT group among the three groups. During a mean follow-up of 15 ± 8 months, AF recurrence and MACE occurred in 56 (25%) and 9 (4%) patients, respectively. The high hs-TnT group had the highest incidence of AF recurrence and MACE among the three groups (high: 39% and 15%, medium: 22% and 2%, and low: 19% and 0%, respectively; log-rank P < .05). In multivariate analysis, hs-TnT greater than or equal to 0.014 µg/L and persistent AF were independent predictors of the composite endpoint.

CONCLUSION

Hs-TnT may be a useful marker for predicting AF recurrence or MACE after AF ablation.