Western AF 2023: "Early" Atrial Fibrillation: Definition and Management

© 2023 HMP Global. All Rights Reserved.

Any views and opinions expressed are those of the author(s) and/or participants and do not necessarily reflect the views, policy, or position of EP Lab Digest or HMP Global, their employees, and affiliates. 

Featured is the presentation entitled “"Early" Atrial Fibrillation: Definition and Management” from WAFib 2023.

I am taking over this presentation for Isabelle van Gelder, who unfortunately cannot be here. First, thank you Nassir for inviting me. I have been looking forward to this meeting since last year’s meeting. So, early AF—that is a definition which is not really mentioned in current guidelines, but is now occurring more and more in a lot of different trials. I will not refer here to screening to detect AF but only clinical presentation of early AF. We already heard that AF often starts with symptoms of palpitations and impaired exercise tolerance and fatigue. This is how our patients present early or later to us electrophysiologists. It's important to realize that early AF can very often be a wakeup call. It is not very often an emergency scenario, but it can be a wakeup call where potentially other underlying causes and modifiable conditions might occur that are important for the manifestation in AF. We also know that early AF is associated with a lot of complications. For example, you can see from the GARFIELD registry of 17,000 patients in an AF outpatient clinic that a lot of them were new-onset AF (46%). Then, if you look at when most of those complications (mortality, stroke, major bleedings) actually occur in those patients, it is very often predominantly within the first month after the initial presentation with AF. This indicates there is a period where AF patients are quite vulnerable and where management of AF is important. Early AF can present in different AF patterns. Here is data from the RACE V registry, where 200 patients in different Dutch centers were monitored with loop recorders or pacemakers for 6 months. You can see that in those early paroxysmal AF patients, a lot of patients did not have any AF episode within 2 years of follow-up after the initial presentation. It's also important to realize that early AF patients who present with AF very often just show quite low AF burden in the follow-up of 2 years. On the topic of early rhythm control, this is why early AF becomes more and more important, but definitions are not the same, so I would like to go through 4 different trials now. The first is the RACE 3 trial. This is early AF patients with paroxysmal AF who presented within 3 months with persistent AF and had a total history of AF of less than 5 years as well as earlier heart failure manifestation. So, RACE 3 was persistent AF within 3 months. Then there was the EAST trial. We will come back to this presentation and this study, but this was any AF from first diagnosis of AF within 1 year. Both trials used predominantly antiarrhythmic drugs for the prevention of recurrent AF. Now to ablation trials, EARLY AF and STOP AF. Those are 2 trials where mainly cryoablation was used to prevent the recurrence of AF, including that criterion was mainly paroxysmal AF within 2 years. So, 1 year in EAST and 2 years in those 2 trials. The question is, is this really very early AF which was studied there, and were the treatment of those patients really different? So, early rhythm control and definition of AF differs among trials. This also indicates that the comparison might be a little difficult. Sometimes early AF is mainly determined by duration, since when AF has been diagnosed, a lot of biochemical markers, fibrosis, dimension of the left atrium, and all those parameters are not incorporated at the moment in the definition of early AF. When we think, then, about how should early AF be managed, we should also go back to those 4 trials. In RACE 3, those were the persistent early AF patients. The first outcome was sinus rhythm at 1 year, which could be improved in this trial. Then, in EAST, the first outcome was actually not a rhythm outcome, but a composite of cardiovascular death, stroke, hospitalization for worsening of heart failure, or acute coronary syndrome, and the follow-up was 5 years. If we go a little deeper in the EAST study, I think it's very interesting to see that there are also a lot of different early AF patients who included, those who were paroxysmal, those who were persistent AF, but importantly, also first diagnosed AF patients. In all those substudies of AF patterns, the composite primary endpoint could be reduced. So, early rhythm control works in all those AF patterns when it comes to the reduction of composite endpoints. But, and this is interesting to see, if you go to the first diagnosed AF patients, you can indeed review the composite endpoint, but the presentation for hospitalization and also the occurrence of acute coronary syndrome is particularly increased in those first diagnosed AF patients during follow-up. Interestingly, this is also occurring in the early rhythm control arm of this study. So, this really indicates that an intensive early rhythm control strategy also needs to be combined with a concomitant condition management. When we now go to the to the ablation trials, mainly rhythm endpoints were observed and the first outcomes were freedom from atrial flutter, AF, and atrial tachycardias longer than 30 seconds, mainly recorded by an implantable loop recorder. The interesting thing is also early AF patients can present with different AF patterns, so paroxysmal, persistent, first diagnosed AF, but some of those patients might also progress to persistent AF. Again, data from the RACE 5 registry, where we saw that within 2-year follow-up, 87% of patients did not progress to persistent AF, but 12.2% did progress within 2 years. Meaning, a 5.5% progression incidence per year, and this was either an increase of more than 3% AF burden. This occurred in 3.8% or a progression to persistent or permanent AF, which occurred in 8.4% of all patients. So indeed, even in those early paroxysmal AF patients, the progression of AF is present and needs to be observed. There was also just recently a substudy of the early AF population published. You can see here that early rhythm control strategy can even reduce and prevent the progression of AF in those early AF patients. The question is, is it just about giving ablation or antiarrhythmic drugs to our patients, or is it also important that our patients are in sinus rhythm? Is it just the approach of rhythm control that is important, or is it important that patients are in sinus rhythm? Here you can see a subanalysis of the EAST trial. This was a very complex statistical and modeling analysis, but the main message here is the only predictor for the response to early rhythm control is being in sinus rhythm during the ECG at 12-month follow-up. So, this is the only independent predictor of whether a patient is effectively manageable by early rhythm control or not. We wrote an editorial about this, and the main question is, how should we now ensure that our patients are in sinus rhythm at 1-year follow-up and also at 1 year after the initial presentation? We must realize that in a lot of patients, it is not just doing cryo once or starting an antiarrhythmic drug once; there are recurrences. So, we need to think about we can manage those recurrences and how to manage this in a better way. Here you can see a summary of the AFNET/EHRA consensus document which we previously put together. This more or less represents the natural time course of the patient journey where a lot of patients go through initial antiarrhythmic drugs, ablation, or cardioversion. We need to think about how we should organize redo procedures, when we should say that rhythm control itself is not possible, and when we should go for an ablate and pace or other strategies in our patients. This is unknown and needs to be studied further. The very important thing is that it is not just ablation or antiarrhythmic drugs, but one of the main pillars of rhythm control strategy is still risk factor modification, which is really recommended in the guidelines and particularly in the early presentation of early AF patients. There is a lot to do to manage those complementary conditions. Thank you.

The transcripts have been edited for clarity and length.