Low Rates of Major Complications for Radiofrequency Ablation of Atrial Fibrillation Maintained Over 14 Years: A Single Centre Experience of 2750 Consecutive Cases

Severe Periprocedural Complications After Ablation for Atrial Fibrillation: An International Collaborative Individual Patient Data Registry

BACKGROUND

Catheter ablation for atrial fibrillation (AF) including pulmonary vein isolation and possibly further substrate ablation is the most common electrophysiological procedure. Severe complications are uncommon, but their detailed assessment in a large worldwide cohort is lacking.

OBJECTIVES

The aim of this study was to determine the incidence of periprocedural severe complications and to provide a detailed characterization of the diagnostic evaluation and management of these complications in patients undergoing AF ablation.

METHODS

Individual patient data were collected from 23 centers worldwide. Limited data were collected for all patients who underwent catheter ablation, and an expanded series of data points were collected for patients who experienced severe complications during periprocedural follow-up. Incidence, predictors, patient characteristics, management details, and overall outcomes of patients who experienced ablation-related complications were investigated.

RESULTS

Data were collected from 23 participating centers at which 33,879 procedures were performed (median age 63 years, 30% women, 71% radiofrequency ablations). The incidence of severe complications (n = 271) was low (tamponade 6.8‰, stroke 0.97‰, cardiac arrest 0.41‰, esophageal fistula 0.21‰, and death 0.21‰). Age, female sex, a dilated left atrium, procedure duration, and the use of radiofrequency energy were independently associated with the composite endpoint of all severe complications. Among patients experiencing tamponade, 13% required cardiac surgery. Ninety-three percent of patients with complications were discharged directly home after a median length of stay of 5 days (Q1-Q3: 3-7 days).

CONCLUSIONS

This large worldwide collaborative study highlighted that tamponade, stroke, cardiac arrest, esophageal fistula, and death are rare after AF ablation. Older age, female sex, procedure duration, a dilated left atrium, and the use of radiofrequency energy were associated with severe complications in this multinational cohort. One in 8 patients with tamponade required cardiac surgery.

2023 Cardiac Society of Australia and New Zealand Expert Position Statement on Catheter and Surgical Ablation for Atrial Fibrillation

Catheter ablation for atrial fibrillation (AF) has increased exponentially in many developed countries, including Australia and New Zealand. This Expert Position Statement on Catheter and Surgical Ablation for Atrial Fibrillation from the Cardiac Society of Australia and New Zealand (CSANZ) recognises healthcare factors, expertise and expenditure relevant to the Australian and New Zealand healthcare environments including considerations of potential implications for First Nations Peoples. The statement is cognisant of international advice but tailored to local conditions and populations, and is intended to be used by electrophysiologists, cardiologists and general physicians across all disciplines caring for patients with AF. They are also intended to provide guidance to healthcare facilities seeking to establish or maintain catheter ablation for AF.

Early mortality after inpatient versus outpatient catheter ablation in patients with atrial fibrillation

BACKGROUND

Rates of early mortality and complications after catheter ablation (CA) of atrial fibrillation (AF) vary across health care settings.

OBJECTIVE

The purpose of this study was to identify the rate and predictors of early mortality (within 30 days) after CA in the inpatient and outpatient settings.

METHODS

Using the Medicare Fee for Service database, we analyzed 122,289 patients who underwent CA for treatment of AF between 2016 and 2019 to define 30-day mortality in both inpatients and outpatients. Odds of adjusted mortality were assessed with several methods, including inverse probability of treatment weighting.

RESULTS

Mean age was 71.9 ± 6.7 years, 44% were women, and mean CHA2DS2-VASc score was 3.2 ± 1.7. Overall, 82% underwent AF ablation as an outpatient. Mortality rate 30 days after CA was 0.6%, with inpatients accounting for 71.5% of deaths (P <.001). Early mortality rates were 0.2% for outpatient procedures and 2.4% for inpatient procedures. The prevalence of comorbidities was significantly higher in patients with early mortality. Patients with early mortality had significantly higher rates of postprocedural complications. After adjustment, inpatient ablation was significantly associated with early mortality (adjusted odds ratio [aOR] 3.81; 95% confidence interval [CI] 2.87-5.08; P <.001). Hospitals with high overall ablation volume had 31% lower odds of early mortality (highest vs lowest tertile: aOR 0.69; 95% CI 0.56-0.86; P <.001).

CONCLUSION

AF ablation conducted in the inpatient setting is associated with a higher rate of early mortality compared with outpatient AF ablation. Comorbidities are associated with enhanced risk of early mortality. High overall ablation volume is associated with a lower risk of early mortality.

Procedure-Related Complications of Catheter Ablation for Atrial Fibrillation

BACKGROUND

Catheter ablation of atrial fibrillation (AF) is a commonly performed procedure. However, it is associated with potentially significant complications. Reported procedure-related complication rates are highly variable, depending in part on study design.

OBJECTIVES

The purpose of this systematic review and pooled analysis was to determine the rate of procedure-related complications associated with catheter ablation of AF using data from randomized control trials and to assess temporal trends.

METHODS

MEDLINE and EMBASE databases were searched from January 2013 to September 2022 for randomized control trials that included patients undergoing a first ablation procedure of AF using either radiofrequency or cryoballoon (PROSPERO, CRD42022370273).

RESULTS

A total of 1,468 references were retrieved, of which 89 studies met inclusion criteria. A total of 15,701 patients were included in the current analysis. Overall and severe procedure-related complication rates were 4.51% (95% CI: 3.76%-5.32%) and 2.44% (95% CI: 1.98%-2.93%), respectively. Vascular complications were the most frequent type of complication (1.31%). The next most common complications were pericardial effusion/tamponade (0.78%) and stroke/transient ischemic attack (0.17%). The procedure-related complication rate during the most recent 5-year period of publication was significantly lower than during the earlier 5-year period (3.77% vs 5.31%; P = 0.043). The pooled mortality rate was stable over the 2 time periods (0.06% vs 0.05%; P = 0.892). There was no significant difference in complication rate according to pattern of AF, ablation modality, or ablation strategies beyond pulmonary vein isolation.

CONCLUSIONS

Procedure-related complications and mortality rates associated with catheter ablation of AF are low and have declined in the past decade.

Effect of Left Atrial Pulmonary Vein Angiography on Safety and Efficacy for High-Power, Short-Duration Pulmonary Vein Isolation in Patients with Atrial Fibrillation

Imaging of pulmonary vein (PV) anatomy by angiography before pulmonary vein isolation (PVI) for atrial fibrillation (AF) has long been standard practice in many centers. Nowadays, very accurate anatomical maps can be generated by the use of high-resolution mapping catheters, and very effective ablation lesions can be generated by the use of the high-power, short-duration (HPSD) technique. In our center, PV angiography was routinely performed before PVI. However, since there is no clear evidence for this, we refrained from performing PV angiography. This study aimed to investigate whether PV angiography is still necessary when using high-resolution mapping catheters after ablation in the high-power, short-duration (HPSD) technique. A total of 139 consecutive patients with atrial fibrillation (66.25 ± 11.68 years old, 62.39% male) undergoing radiofrequency PVI were included in the study. Ablation was performed with the HPSD technique using a fixed protocol for energy delivery of 50 watts (contact force 3-20 g). We observed no significant effect on the efficacy, efficiency and complications of the ablation procedure if pulmonary vein angiography was omitted before HPSD PVI. Thus, using our protocol, it may be useful that PV angiography is avoided, especially in young patients and those with chronic renal disease.

A computational comparison of radiofrequency and pulsed field ablation in terms of lesion morphology in the cardiac chamber

Pulsed Field Ablation (PFA) has been developed over the last years as a novel electrical ablation technique for treating cardiac arrhythmias. It is based on irreversible electroporation which is a non-thermal phenomenon innocuous to the extracellular matrix and, because of that, PFA is considered to be safer than the reference technique, Radiofrequency Ablation (RFA). However, possible differences in lesion morphology between both techniques have been poorly studied. Simulations including electric, thermal and fluid physics were performed in a simplified model of the cardiac chamber which, in essence, consisted of a slab of myocardium with blood in motion on the top. Monopolar and bipolar catheter configurations were studied. Different blood velocities and catheter orientations were assayed. RFA was simulated assuming a conventional temperature-controlled approach. The PFA treatment was assumed to consist in a sequence of 20 biphasic bursts (100 µs duration). Simulations indicate that, for equivalent lesion depths, PFA lesions are wider, larger and more symmetrical than RFA lesions for both catheter configurations. RFA lesions display a great dependence on blood velocity while PFA lesions dependence is negligible on it. For the monopolar configuration, catheter angle with respect to the cardiac surface impacted both ablation techniques but in opposite sense. The orientation of the catheter with respect to blood flow direction only affected RFA lesions. In this study, substantial morphological differences between RFA and PFA lesions were predicted numerically. Negligible dependence of PFA on blood flow velocity and direction is a potential important advantage of this technique over RFA.

Relationship between procedural volume and complication rates for catheter ablation of atrial fibrillation: a systematic review and meta-analysis

AIMS

There are conflicting data as to the impact of procedural volume on outcomes with specific reference to the incidence of major complications after catheter ablation for atrial fibrillation. Questions regarding minimum volume requirements and whether these should be per centre or per operator remain unclear. Studies have reported divergent results. We performed a systematic review and meta-analysis of studies reporting the relationship between either operator or hospital atrial fibrillation (AF) ablation volumes and incidence of complications.

METHODS AND RESULTS

Databases were searched for studies describing the relationship between operator or hospital AF ablation volumes and incidence of complications which were published prior to 12 June 2020. Of 1593 articles identified, 14 (315 120 patients) were included in the meta-analysis. Almost two-thirds of the procedures were performed in low-volume centres. Both hospital volume of ≥50 and ≥100 procedures/year were associated with a significantly lower incidence of complications compared to <50/year (4.2% vs. 5.5%, OR = 0.58, 95% CI 0.50-0.66, P < 0.001) or <100/year (5.5% vs. 6.2%, OR = 0.62, 95% CI 0.53-0.73, P < 0.001), respectively. Hospitals performing ≥50 procedures/year demonstrated significantly lower mortality compared with those performing <50 procedures/year (0.16% vs. 0.55%, OR = 0.33, 95% CI 0.26-0.43, P < 0.001). A similar relationship existed between proceduralist volume of <50/year and incidence of complications [3.75% vs. 12.73%, P < 0.001; OR = 0.27 (0.23-0.32)].

CONCLUSION

There is an inverse relationship between both hospital and proceduralist AF ablation volume and the incidence of complications. Implementation of minimum hospital and operator AF ablation volume standards should be considered in the context of a broader strategy to identify AF ablation Centers of Excellence.

Inpatient hospital procedural volume and outcomes following catheter ablation of atrial fibrillation

INTRODUCTION

The real-world distribution of hospital atrial fibrillation (AF) ablation volume and its impact on outcomes are not well-established. We sought to examine patient characteristics, complications, and readmissions after AF ablation stratified by hospital procedural volume.

METHODS AND RESULTS

Using the nationally representative inpatient Nationwide Readmissions Database, we evaluated 54 597 admissions for AF ablation between 2010 and 2014. Hospitals were categorized according to tertiles of annual AF ablation volume. Index complications, 30-day readmissions, and early mortality were examined. Multivariable logistic regression was performed to assess the predictors of adverse outcomes. Between 2010 and 2014, low volume tertile hospitals accounted for 79.3% of hospitals performing AF ablations. When stratified by first, second, and third volume tertiles, complication and early mortality rates were higher in low volume centers (8.9% and 0.67% vs 6.1% and 0.33%, vs 4.5% and 0.16%, respectively; P < .001). Patients undergoing AF ablation at low volume centers were older and had a higher prevalence of congestive heart failure, coronary artery disease, and other comorbidities. Low volume hospitals were associated with increased cardiac perforation (adjusted odds ratio [aOR], 4.79; P < .001), vascular complications (aOR 1.49; P < .001), and any complication (aOR 2.06; P < .001) during index admission as well as increased early mortality (aOR 2.43; P = .039).

CONCLUSIONS

Among patients hospitalized for AF ablation, low inpatient AF ablation hospital volume was associated with worse outcomes following ablation, which was exacerbated by a greater comorbidity burden among patients at these centers.

Risk of Mortality Following Catheter Ablation of Atrial Fibrillation

BACKGROUND

Although procedure-related deaths during index admission following catheter ablation of AF have been reported to be low, adverse outcomes can occur after discharge. There are limited data on mortality early after AF ablation.

OBJECTIVES

This study aimed to identify rates, trends, and predictors of early mortality post-atrial fibrillation (AF) ablation.

METHODS

Using the all-payer, nationally representative Nationwide Readmissions Database, we evaluated 60,203 admissions of patients 18 years of age or older for AF ablation between 2010 and 2015. Early mortality was defined as death during initial admission or 30-day readmission. Based on International Classification of Diseases-9th Revision, Clinical Modification codes, we identified comorbidities, procedural complications, and causes of readmission following AF ablation. Multivariable logistic regression was performed to assess predictors of early mortality.

RESULTS

Early mortality following AF ablation occurred in 0.46% cases, with 54.3% of deaths occurring during readmission. From 2010 to 2015, quarterly rates of early mortality post-ablation increased from 0.25% to 1.35% (p < 0.001). Median time from ablation to death was 11.6 (interquartile range [IQR]: 4.2 to 22.7) days. After adjustment for age and comorbidities, procedural complications (adjusted odds ratio [aOR]: 4.06; p < 0.001), congestive heart failure (CHF) (aOR: 2.20; p = 0.011) and low AF ablation hospital volume (aOR: 2.35; p = 0.003) were associated with early mortality. Complications due to cardiac perforation (aOR: 2.98; p = 0.007), other cardiac (aOR: 12.8; p < 0.001), and neurologic etiologies (aOR: 8.72; p < 0.001) were also associated with early mortality.

CONCLUSIONS

In a nationally representative cohort, early mortality following AF ablation affected nearly 1 in 200 patients, with the majority of deaths occurring during 30-day readmission. Procedural complications, congestive heart failure, and low hospital AF ablation volume were predictors of early mortality. Prompt management of post-procedure complications and CHF may be critical for reducing mortality rates following AF ablation.

Arrhythmia recurrence is more common in females undergoing multiple catheter ablation procedures for persistent atrial fibrillation: Time to close the gender gap

BACKGROUND

Female gender is associated with an increased recurrence of atrial fibrillation (AF) after catheter ablation (CA). Although AF is more common in men, women constitute a significant proportion with persistent atrial fibrillation (PsAF).

OBJECTIVE

The purpose of this study was to determine whether multiple ablation procedures improves arrhythmia outcomes in females with PsAF compared to men.

METHODS

We performed a multicenter observational study to determine long-term arrhythmia outcomes in patients undergoing >1 CA for PsAF. CA involved pulmonary vein (PV) isolation with additional ablation including linear, posterior wall isolation, electrogram-guided, or a combination of these.

RESULTS

A total of 281 patients had >1 ablation procedure for PsAF and were included in this analysis (mean age 58.7 ± 9.3 years; 86 [30.6%] female; left atrial [LA] area 27.0 ± 5.3 cm²; PsAF duration 1.7 ± 1.7 years). At mean follow-up of 45.5 ± 31.8 months, freedom from recurrent AF was present in 148 patients(52.7%) after 2.2 ± 0.5 procedures. After multivariate analysis, female gender (hazard ratio [HR] 2.10; P <.001) and enduring PV isolation (HR 1.64; P = .01) were independently associated with AF recurrence. Enduring PV isolation was significantly higher in women than in men (33.7% vs 19.5%; P = .01).

CONCLUSION

Female gender was independently and strongly associated with arrhythmia recurrence in patients undergoing multiple procedures for PsAF. PV reconnection was less likely, and fewer reconnected PVs occurred in women. Further studies are required to better understand the mechanisms responsible for AF in females to assist in closing the gender gap in the success of CA.

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).

Right phrenic nerve palsy following transcatheter radiofrequency current atrial fibrillation ablation: Case report

Phrenic nerve palsy (PNP) is a well-known complication of cardiac surgery or jugular/subclavian vein catheterization, presenting with cough, hiccups, dyspnoea/shortness of breath and, in some cases, ventilatory failure. Rarely, PNP is a complication of transcatheter radiofrequency ablation for atrial fibrillation. This report describes the case of a 72-year-old woman with a 2-year history of recurrent paroxysmal atrial fibrillation associated with occasional palpitations and shortness of breath who underwent routine transcatheter radiofrequency ablation. Three days after the procedure, the patient developed shortness of breath and progressive dyspnoea. Motor nerve conduction showed the absence of the right phrenic nerve compound motor action potential compared with the normal left side confirming the diagnosis of a right phrenic nerve palsy. This current case demonstrated the importance of undertaking an electrophysiological evaluation of phrenic nerve conduction after transcatheter radiofrequency ablation in patients presenting with palpitations and shortness of breath even if present a few days after the procedure.

The use of lobectomy for management of clinically significant pulmonary vein stenosis and occlusion refractory to percutaneous intervention

Pulmonary vein stenosis (PVS) is a serious complication of radiofrequency ablation (RFA) for the treatment of atrial fibrillation. The prevalence of this complication was reported to be as high as 42% in 1999 when RFA was first implemented [1]. However, with improvements in operator technique including wide area circumferential ablation, antral isolation, and the use of intracardiac ultrasound, the incidence of symptomatic severe PVS following RFA ranges from 0% to 2.1% while the incidence of symptomatic pulmonary vein occlusion (PVO) following RFA was found to be 0.67% [2–8]. Despite a decrease in the incidence of clinically significant PVS following RFA, there have been increased reports of complications associated with PVS to include hemoptysis, scarring, lung infarction, and intraparenchymal hemorrhage [9]. Studies have shown that PVS is often misdiagnosed as pneumonia, pulmonary embolism, and lung cancer and as a result, patients are often subjected to unnecessary diagnostic procedures [2,10].

The current first line treatment for this condition is percutaneous balloon angioplasty with stenting; however, there are studies that have shown that there is a relatively high rate of restenosis despite optimal medical therapy [2–3,10,11]. Three case reports have described the use of lobectomy to treat patients with persistent respiratory symptoms in the setting of severe PVO with good outcomes [12–14]. We present a case of iatrogenic PVO and ipsilateral severe PVS following RFA who underwent attempted lobectomy for persistent exertional dyspnea and persistent hypoperfusion of the left upper lung lobe despite percutaneous intervention and six months of optimal medical therapy. The lobectomy was aborted due to the presence of a significant fibrothorax, and the patient continues to have significant exercise limitation despite participation in pulmonary rehabilitation.