Oussama Wazni, MD, Section Head, Cardiac Electrophysiology and Pacing and Bruce Lindsay MD, past Section Head and past president of Heart Rhythm Society discusses the challenges and findings from the CABANA trial and its implications on future clinical practice, when to offer ablation vs. medical management.
Good morning i’m misawa’s and the section head of cardiac electrophysiology at the cleveland clinic and with me here is dr. lindsay the past section had immediate past section head of cardiac electrophysiology at the cleveland clinic also dr. lindsay was a past president of heart rhythm society both of us are thrilled to be here this morning to talk about the
Cabinet line and its implications on our clinical work everyday work in ep dr. lindsay will take the lead and i will be i will be discussing with him they studied in detail cabana is a very interesting trial it was one that really was designed to look at additional benefits from going through an ablation and what i mean by that is that most patients come to us for
Ablation procedures because they have symptomatic atrial fibrillation many of them either medicines have failed to control their arrhythmias or were not tolerated and then they came to us because they they needed relief from the kind of symptoms they had because for many people atrial fibrillation has a significant burden on quality of life in some instances patients
Also looked at the risks of taking medicines and just didn’t want to take them so that’s really why we do ablation procedures to improve quality of life the question really raised by that cabaña focused on is whether it reduces the risks of death stroke bleeding or cardiac arrest and that was a combined endpoint that they looked at to see whether it would make a
Difference they also looked at all cause mortality and hospitalization recurrence tatro fibrillation and certain other secondary endpoints so in doing this trial it was difficult to put it in perspective we had a great challenge in recruiting patients for it because they came to us because they were symptomatic they wanted to have something done and they didn’t
Want to be randomized to a drug limb which maybe they’d already failed so right there you all you have kind of an immediate challenge in doing a study like this it was known that there would be a big / from one treatment lived limb to the other and dr. packer and the statisticians tried to account for that in designing the clinical trial but it was a difficult
Trial to do and i think it will evoke controversy over the next five or six years as we analyze results so some of you may want to give your perspective so this was a challenging title from all aspects even would be enrollment goals so the enrollment goals was to start with with about 5,000 patients and that was now down to about 3,000 and even less well the trial
Was finally concluded but nevertheless dr. lindsay tell us about you know the the overall findings of the study and how these findings can apply to our daily activity with our patients yes in round numbers there were 2,000 patients enrolled in the study a thousand h limb so one limb got medical therapy and the other limb underwent ablation procedures and about 20%
Of the patients who went through oblations required a second ablation the problem was this about 9% of the patients who were supposed to get ablations never did and it’s not quite clear why whether there were financial issues or whether they changed their mind or could have they been too sick now that’s a problem because it would bias the results on the other side
There were a substantial number of patients if i recall correctly about 27% who crossed over from drug therapy to ablation and that was a little higher crossover than i think was anticipated in this study so whenever you do it an intention-to-treat analysis it’s very difficult when there’s a big crossover and people really didn’t get exactly the treatment they were
Supposed to get nonetheless and looking at these parameters by an intention-to-treat analysis the all-cause mortality was there were modest reductions all cause mortality was about 6% less with ablation therapy a very modest reduction in absolute returns and then there was a substantial reduction in the time to recurrence of atrial fibrillation this is something
We’ve seen in the past that ablation tends to be more effective now again to put this in perspective about 47% of the patients had persistent as opposed to a paroxysmal atrial fibrillation maybe 9 or 10 percent had long-standing persistent a persistent is a very broad definition that it covers people who had atrial fibrillation from anywhere from a week to months
And so that that in itself raises some issues but nonetheless it was a distribution of patients commonly seen in the office actually actually for me i thought that the results were very encouraging because they can be intention-to-treat analysis and all the statistical analysis aside it this is a big study that showed that actually ablation works it keeps people
In sinus rhythm more than medical treatment it also showed that ablation is a safe strategy and those patients the complication it was very very low and then if we take into account subgroup analysis for example younger patients and patients who have heart failure those patients tended to do much better when they had an ablation versus medical treatment and this
Especially with the regards to the patients who have heart failure it corroborates the findings from castle hf afib study and which patients were randomized to either ablation versus medical therapy in patients who had heart failure and the ones who had an ablation did a lot better so in that sense i think cabana is very encouraging unfortunately again it was a very
Challenging study to enroll in and even when patients were enrolled it was very hard to get patients to stick to the arm of treatment and frankly the fact that a lot of patients who were supposed to get medical therapy ended up getting ablation even though they’re in a study means that medical therapy is not something that patients want to stick with for the long
End and and to put this in perspective though it’s difficult to know what to do with an intention-to-treat analysis where there’s so much crossover if you took the patience as to what they were actually treated with there was a reduction in cardiovascular mortality there was a reduction substantial reduction in hospitalizations for cardiovascular problems and the
Primary endpoint was reduced by a relative 30 23 % so where the debate will occur over the next years is what do you do at the trial with this much crossover and if you go by what the patients were actually treated with well some would argue that there is benefit from actually being treated with an ablation procedure and i think that’s the debate as to whether
That’s a valid way to do it i think part of it is we need to better understand the demographics of the patients who were originally supposed to get an ablation but didn’t and some of the other things that would help us to determine these changes so that’s where the debate will occur but it shouldn’t it shouldn’t detract us from why do patients go through these
Ablations in the first place they go through the ablation to alleviate symptoms that hasn’t changed this study wasn’t about that if anything it was supported because the recurrence rates were lower in peach at people who had ablations the real question is is there additional benefit and the answer i suppose is maybe but this study will provoke a lot of discussion
Over that very subject so here at the clinic we have been working very hard to determine the subgroup patients a group of patients who will benefit from ablation especially if it’s done sooner than later and our data is consistent that the sooner we intervene with an ablation the better overall outcomes especially in younger patients and in patients who have heart
Failure so actually i am very very encouraged with the results from cabana now i think in the future there will be studies and that will be a smaller scale i don’t think we’re going to be able to do such a large study first of all because people you don’t have learned the lesson that such a study is very difficult to manage and to conduct in the first place but i
Think overall we will continue to have data even if it’s retrospective analysis that will show that you know ablation is here to stay first for symptom relief and secondly i think patients will do better overall by getting an ablation or at least suppressing atrial fibrillation somehow without the you know bad side effects that the patients have from medications
I think it’s important for patients and physicians to understand that it’s a progressive disorder and as the sangha has pointed out earlier intervention according to our data seems to offer better outcomes than if you wait too long in the course of disease where patients get progressive changes in their hea which are harder to reverse and there is data from castle
Trial and other data suggesting that for patients who have heart failure you can reduce the rate of hospitalization by getting them back to the normal rhythm and there’s a lot of judgment and selection and making these kinds of decisions some people who are doing well they don’t need to go through this necessarily but for those who do have symptoms or in whom
Management would be difficult because of progressive heart failure i think that that’s where it’s more clear that the ablation procedure offers a benefit and as for these other parameters that we’ve discussed well we’ll see what the debate brings us over the next five or six years so in our practice how would you describe the patient that we now typically will you
Know offer them an ablation for for me it tends to be patients who come from around the country who have been tried on medications they have a lot of symptoms and they they aren’t doing very well so those aren’t patients that i can randomize to one versus the other and that was one of the challenges that i had in recruiting patients for cabaña there are also
Patients who’ve read about the risks of taking anti rhythmic medications and also recognized that the efficacy of these medicines is relatively low so there are the discussion centers on the fact that ablation procedures aren’t perfect either but this is what the potential benefits are in alleviating their symptoms then there’s a small percentage of patients
Who may want to go through the blasian procedure to come off of anticoagulation what i explained to those patients is that that’s generally not the reason to go through an ablation procedure and there and there’s a there’s a consensus that because of the relatively high recurrence rates related to a atrial fibrillation after ablation that in somebody who has a
Significant stroke risk you can’t just stop the anticoagulation now in people with lower stroke risk if they’re monitored repeatedly and say they’re a year out then i could have that discussion but they continue to require close follow-up and monitoring and there are now a lot of devices that they can use with their cell phones to check the rhythm and see what
That is so that provides a a potential opportunity for those patients though it’s not real well proven as to whether that’s the best thing to do and perhaps you have some other there’s one more there’s a lot more group of patients that i would also consider an ablation on it and that’s the patient who’s may not be very symptomatic but it’s very clear that the left
Ventricular function is starting to suffer either the lv is starting to dilate or the ejection fraction is starting to drop so in those patients even though they would say that there might be symptomatic i would offer them an ablation in order to control the afib because there has been a study recently the camera afib study which was published in jack that showed
That even and they controlled atrial fibrillation a patient can develop lv dysfunction and if we can restore normal rhythm then the lv dysfunction improves especially if there is no scar on mri so i think that’s a subset of patients that i would consider an ablation sooner than later even if they’re not dancing too much yeah that’s a good point and many patients
Are referred to us come from heart failure doctors where they’re having difficulty managing it and feel that if we could help them get the patients back into sinus rhythm it would be beneficial also to put this in perspective treatment of atrial fibrillation is not that it’s only ablation or only medications all our data and our goals are based on getting people
Back to a normal rhythm and getting them off of medications but there are some in whom a combined approach is necessary and that’s just reality but if we can get somebody who’s struggling with atrial fibrillation even if they’re not completely cured if we can reduce the burden of atrial fibrillation or perhaps control with medications they’ll come back to us saying
That their quality of life is much better i want to thank you dr. lindsay as always the discussion has always been a great i think the summary is we still have a lot of patients that need our help with an ablation either because they can’t tolerate the medications the medications are not working they want to come off an anticoagulant or because they’re developing
Heart failure and i think i want to thank you again for a great discussion i always learn a lot right here sitting here and hearing from you i think one of the advantages we have is we get to bounce ideas off of each other so thanks very much thank you
Transcribed from video
Catheter Ablation vs Antiarrhythmic Drug Therapy in Atrial Fibrillation CABANA – What did we learn By Cleveland Clinic
