Ablation of paroxysmal and persistent atrial fibrillation in the very elderly real‐world data on safety and efficacy

Abstract Background The role and technique of catheter ablation of atrial fibrillation (AF) in the elderly is unclear. While in young patients pulmonary vein isolation (PVI) has evolved as first option, in older patients decision is often made in favor of drugs as higher complication rates and less benefit are suspected. Therefore, data on PVI of paroxysmal and persistent AF in these patients is still sparse but of eminent importance. Hypothesis PVI is comparably safe in the very elderly with similar recurrence and complication rates. Methods We enrolled all patients (n = 146) aged >75 years who underwent a first PVI over a period of 10 years (2009‐2019) from our prospective single‐center ablation registry. Mean follow‐up time was 231 ± 399 days. Results Acute ablation success defined as complete PVI and sinus rhythm at the end of the ablation procedure was high (99%). Severe periprocedural complications occurred in 3.3% (stroke/TIA n = 2; 1.3%; pericardial effusion n = 3; 2%). In 4.6% of patients symptomatic sick‐sinus‐syndrome was unmasked after PVI resulting in pacemaker implantation. There were no deaths related to PVI. Recurrence rate of symptomatic AF was 37.3% resulting in a Re‐PVI and/or substrate ablation in 32 pts (20.9%). During follow‐up pacemaker implantation plus atrioventricular node ablation was performed in 10 pts (6.8%). There was a trend toward lower recurrence rates with single‐shot devices (cryoballoon, multielectrode phased‐radiofrequency ablation catheter) than with point‐by‐point radiofrequency while complication rates did not differ. Conclusion PVI for AF is a feasible treatment option also in patients >75 years with a reasonable success and safety profile. Higher success rates occurred in patients treated with a single‐shot device as compared to point‐by‐point ablation.


| INTRODUCTION
Atrial fibrillation (AF) is the most common atrial arrhythmia. With increasing age AF is becoming clinically manifest in a growing number of patients. In parallel, the need and wish for definitive therapy is growing due to improved ablation techniques with higher success and low-complication rates. Catheter ablation has developed as first line therapy in various arrhythmias. This is reflected in a strengthening of ablation in the recently updated ESC guidelines for the management of supraventricular tachycardias. 1 Interestingly, recommendations are not age-dependent. In AF, however, many centers have an individual age limit for ablation. 2 Pulmonary vein isolation (PVI) has been developed as the cornerstone of AF ablation. Specific data on AF ablation of patients >75 years was first published by Nademannee et al. 3 in 2015. A recent multicentre study presented high-success rates in 104 patients ≥75 years who underwent PVI with the cryoballoon. 4 In order to compare a "single-shot" strategy such as the cryoballoon to a point-bypoint ablation approach we performed an analysis of patients >75 years undergoing their first PVI.

| MATERIAL AND METHODS
The study was conducted in accordance with the guidelines of the Declaration of Helsinki. In the present study, we analyzed our prospective single-center database for a period of 10 years (2009-2019).
We included all patients >75 years who underwent their first PVI for drug-refractory highly symptomatic AF. Acute success rates, complications, recurrence rates, redo procedures, and AF therapy during follow-up were recorded.  7 In all groups, the catheter setup was complemented by a decapolar coronary sinus catheter and a quadripolar catheter that was positioned in the right ventricle. After ablation, protone pumpinhibitors were added to the medication of every patient for 4 weeks after ablation to prevent esophageal damage associated to ablation. 8-10

| Statistical analysis
Continuous data are reported as mean ± SD, categorical data are reported as percentages. Statistical analysis was performed using Gra-phPad PRISM 6.0 (San Diego, California) and the SPSS Statistics, version 20.0 (SPSS, Inc., Chicago). A P-value < .05 was considered statistically significant.

| Baseline data and demographics
Concerning baseline characteristics, no significant differences were observed if grouped for ablation device. There were significant differences between patients with paroxysmal and persistent AF regarding gender, LA size, and structural heart disease ( Table 1A). The mean duration from first diagnosis of AF to ablation was 5.3 ± 4.9 years. Mean EHRA stadium was 2.7 ± 0.5 while mean CHA 2 DS 2 -VASc-score was 3.9 ± 1.0. The majority of patients (66%) had no evidence of structural heart disease while among the patients with structural heart diseases ischemic cardiomyopathy was most common (19.2%). A history of tachycardiomyopathy was present in 12 pts (8.2%). All but one patient with a Left Atrial Appendage (LAA) occluder were took oral anticoagulation (42.5% vitamin K antagonists, 57.5% direct oral anticoagulants).

| Follow-up and complications
In patients being ablated with the cryoballoon, recurrence rate was 29.1%, with PVAC 36.6%, and for patients with a 3D mapping guided PVI 46.2% (P = .11, n.s.). In turn, mean follow-up duration was shorter in patients being ablation with cryo (162 days) than with PVAC (340 days) or 3D RF (249 days) (Table 1A and 2A).
Regarding the type of AF, in patients with paroxysmal AF there was a recurrence rate of 29.9% while recurrence rate was 48.7% (P < .05) in patients with persistent AF in the presence of comparable follow-up duration (Table 1B and 2B).
During follow-up, a "pace-and-ablate" therapy for recurrent symptomatic AF with ablation of the atrioventricular node (AVN) was performed in 6.8% of patients.
After ablation symptomatic sick-sinus-syndrome was unmasked in 4.1% of patients who were then implanted with a permanent pacemaker during the same stay. There were no adverse events recorded regarding pacemaker implantation.

| DISCUSSION
In this study, we present data on AF ablation in elderly patients aged over 75 years. We found success rates comparable to those reported in literature with recurrence rates around 30% to 50% during follow-up and low-overall complication rates. As a novel finding, cryoballoon ablation as well as multielectrode phasedradiofrequency ablation tended to be more effective and had similar complication rates compared to conventional RF ablation using 3D mapping systems without reaching statistical significance, mostly due to the low number of patients ablated with RF. A trend toward better results of PVI with the cryoballoon in the elderly patient cohort has already discussed in literature. 11  In contrast to the trial by Metzner et al, 12  reported data from the German ablation registry which revealed an increased mortality when opting for AVN ablation but not when choosing PVI in patients with heart failure and reduced ejection fraction.

| Risk of peri-and post-procedural complications
Major complications only occurred in 3.3% of patients -1.3% with cerebrovascular events, 2% with pericardial effusion. This is in line or even slightly below the complication rates described in previous studies 4,12 and comparable to data from the world-wide survey of AF ablation 20 and to large prospective randomized controlled trials such as the fire-and-ice trial. 21  trials have to be performed to further evaluate this possible advantage.
Only few patients are in need for an AVN ablation during follow-up.

ACKNOWLEDGMENT
There was no funding received concerning this manuscript. All authors declare that they have no conflict of interest concerning the manuscript. Open access funding enabled and organized by Projekt DEAL.

DATA AVAILABILITY STATEMENT
The data that support the findings of this study are available from the corresponding author upon reasonable request. ORCID