Doctor Karlsner, Doctor Schumosky, ladies and gentlemen. It s my real pleasure to participate in this session on controversial issues in the management of ventricular tachycardia and I m sure that will find a lot of controversies here. There might be of course some overlap between my talk and the following talks. So the title of my presentation is When is catheter ablation indicated in patients with ventricular arrhythmias and of course you can look at it first from the patient s perspective and see when from the patient s perspective is it indicated so it refers to the indication but also, it could be correlated to the time which is the cause of the disease. And you could address the important question, should catheter ablation be performed early, or should it be performed late during the course of the disease, which mostly of course, is coronary artery disease or dilated cardiomyopathy. Now let me start first of all to address the first issue, which is the indication for catheter ablation in patients as shown here with structural heart disease including prior myocardial infarction, dilated cardiomyopathy or arrhythmogenic right ventricular disease. Now there was a consensus statement which was published actually, by Doctor Allio and Doctor Stevenson together in 2009, very much like the initiative on catheter ablation of fibrillation and most of what I would like to refer to comes from this expert consensus document where I was also participating. But if we first look into patients as I mentioned before with structural heart disease, then catheter ablation of is recommended first for symptomatic sustained monomorphic VT, including VT, which is terminated by an ICD that recurs despite antiarrhythmic drug therapy or when antiarrhythmic drugs are not tolerated or not desired. Now second, for control of incessant sustained monomorphic VT or VT storm that is not due to a transient reversible cause. Third, for patients with frequent PVCs, non-sustained VTs or VT that is presumed to cause ventricular dysfunction. Fourth, for bundle branch reentry or interfascicular reentry. Fifth, for recurrent sustained polymorphic VT and VF that is refractory to antiarrhythmic drug when there is a suspected trigger and you know that in most of these patients we can eliminate a trigger without even touching the substrate but also sometimes you can eliminate a substrate in the patient population. Furthermore, catheter ablation should be considered in patients who have one or more episodes of sustained monomorphic VT despite therapy with one of more Class I or Class III drugs and in patients with recurrent sustained monomorphic VT due to prior MI who have an ejection fraction less than 30 percent and expectation for 1 year of survival, and is an acceptable alternative to amiodarone therapy. I come back to this in a minute. And finally, catheter ablation should be considered also in patients with haemodynamically stable VT due to prior MI who have reasonably preserved left ventricular dysfunction and ejection fraction above 35 percent even if they have not failed an antiarrhythmic drug. Now for patients with an underlying substrate, particularly patients who have dilated cardiomyopathy and arrhythmogenic right ventricular dysplasia, we should take into consideration that a vast majority of
these patients with these two different substrates may require epicardial mapping and ablation and up to 70 percent whereas in patients with systemic heart disease an epicardial approach is extremely rare. It might more often be an inferior than anterior infarcts but in general, the number is not more than 10 percent but this is something that needs to be considered. If you consider a patient for catheter ablation that when the underlying disease is dilated cardiomyopathy or arrhythmogenic right ventricular dysplasia, that your laboratory should be equipped such that you can perform an epicardial approach, mostly when approach fails. Now if you move to patients without structural heart disease, the recommendation of the task force says that first of all, patients monomorphic VT that is causing severe symptoms should undergo catheter ablation. Second, monomorphic VT when antiarrhythmic drugs are not effective, not tolerated, or not desired. And third, for recurrent sustained polymorphic VT and VF very much like in patients with underlying heart disease, that is refractory to antiarrhythmic therapy when there is a suspected trigger that can be targeted for ablation. That also includes patients with such as short or long QT or the syndrome, where we know that we can identify the trigger in these patients to prevent rapid ventricular tachycardia or ventricular fibrillation which are often leading to ICD shots. Now the more important question maybe for the upcoming years will be, besides others that I ve listed here that I m not going to address. That is the question. What is the optimum time for catheter ablation? And the task force was also thinking about this and we came to the conclusion that in the past, the ablation was often not considered until pharmacological options had been exhausted, often after the patient had suffered substantial mobility from recurrent episodes of VT and ICD shocks. So there was a consensus among the task force members that catheter ablation for VT should generally be considered early in the treatment of patients with recurrent ventricular tachycardia. And this of course, an early catheter ablation would be a change for most centres in their approach to patients with ventricular arrhythmias. Now this is an example of what is quite often discussed should the patient, should every patient, before he s transferred to catheter ablation first get an antiarrhythmic drug, mostly Amiodarone, before he s considered to be a candidate for catheter ablation. Now this is one trial that is looking into this and as you can see, in this trial, the OPTIC trial, the patients were randomized to either beta blockers, Sotalol or Amiodarone plus beta blocker. And there was a significant decrease of ICD interventions in this patient population, particularly under the combination of Amiodarone and beta blockers. However, as we all know, antiarrhythmic drugs in particular, Amiodarone, but also Sotalol, as shown in the OPTIC trial, are often associated with side effects, which require discontinuation of the drugs, and in the OPTIC trial, it was almost 20 percent of patients treated with Amiodarone and 23 percent of patients treated with Sotalol that after one year, did not take one of the two drugs because of side effects. Now, often these drugs will also change the defibrillation threshold or might be ineffective. Actually, until now there is no randomized trial that ever randomize patients in catheter ablation and Amiodarone, and
there was one trial, the CVT trial, which was just recently stopped after one year of including because the inclusion rate was so low that the trial was considered not to be finished within a reasonable time. So we will not have, also not in the future, any information where the patients should first undergo Amiodarone and then catheter ablation or whether catheter ablation should be done even before Amiodarone is considered. Now what is the optimal time then, for catheter ablation particularly in patients who have ICD interventions? Now, there is today some evidence that an early, even before an ICD intervention has been performed, catheter ablation procedure should be considered. We have data on late, mostly after multiple ICD interventions and we have data when catheter ablation is used in emergency situations such as electrical storm. There s no systematic approach whether the ablation should be done after the first, the second or the third shock so there is almost no information available for that patient population here. However, it would be important to have this information because we know, I m not going into details, we know that ICD shocks today, are associated with an increased risk of mortality. And that risk is increasing after the first shock, and it s further increasing after the second shock, and in particular after multiple shocks. So if we would have a strategy, if a drug strategy, but in particular, an ablation strategy, that would prevent the first shock, it would prevent the second shock, and thereby maybe associated with a better prognosis in patients who have shocks from the ICD. This would be of course, a study that at the end of the day, we have to look for that catheter ablation has some impact by preventing shocks on prognosis. Such a study however does not exist at that point in time. No, we also know of course that patients who have an ICD still die suddenly if they have an underlying heart disease in up to 30 percent from SCD despite a functioning ICD. And we also know that recurrent ICD interventions reduce quality of life. Now what are the data that we have in patients after multiple ICD shocks? There are three big nonrandomized trials. One has been published in 2000 by Caulkins. The 2008 study has been published by Doctor Stevenson and the trial that we also participated in was published in 2009. Now as you can see the majority of all these patients had an ICD in place when catheter ablation was performed. The follow up for all of these trials is rather short, ranging from six to 12 months. The mortality over this follow up time is up to 25 percent, so it s still a significant mortality for a rather short period of time. And as you can see, the success rate is validated by the investigators as ranging acutely from 41 to 81 percent. But long term success which is success over the follow up period, which as long as 12 months is somewhat in the range of 50 percent. So in other words, every second patient who undergoes a successful catheter ablation procedure will have a recurrence of some kind of ventricular tachycardia over time. There is one nice and elegant study looking into catheter ablation in patients with electrical storm that has been performed by the group of, and what I would like to stress is, if you look to the number of episodes per patient per day, before the patients finally underwent catheter ablation, then
that number is extremely high. It s 16 episodes, or in other words, it s 14, one-four, ICD shocks per patient per day. You can imagine what kind of trauma this must be if somebody gets 14 shocks in a single day. For recurrent ventricular tachycardia, ventricular fibrillation, and then rather late these patients are sent for catheter ablation. And this as we all know, is the most perfect group to be sent for catheter ablation because for the vast majority of these patients, at least acutely we can suppress the ventricular arrhythmia ventricular tachycardia and thereby suppressing further shocks. Now in this study, it could be demonstrated that there was no recurrence of electrical storm. If patients at the end of the ablation session had either no induced ventricular tachycardia at all or at least not the clinical ventricular tachycardia induced and only those with the ejection of still the clinical tachycardia had recurrences of electrical storm. Furthermore, that could demonstrate that also other types of ventricular tachycardia did not recur when any tachycardia was suppressed at the end of the session. And interestingly, what they also could show, that for those with non-induced VT or at least non- VT of the clinical VT, which is Class A and B patients that there was a significant benefit with respect to death despite the fact that these numbers were relatively small compared to patients who still had the induceable clinical VT Class C patients at the end of the session. Now furthermore we have data from two trials on the value of prophylactic catheter ablation in patients that undergo ICD treatment. That two randomized trials, the US trial that SMASH-VT which included unstable VT/VF patients and the European trial which is the VTACH study which included only stable VT patients. Now you re probably aware that these randomized trials, these are the only randomized trials that are available in catheter ablation that these two randomized trials showed a significant reduction in survival free from ICD therapy and rate patients that underwent catheter ablation in addition to the ICD versus patients that got the ICD only, and that this difference is significant. Please note also that in these patient population with unstable ventricular tachycardia ventricular fibrillation, the recurrence rate over 24 months is rather low at 32 percent. This benefit could also be shown in favour for catheter ablation for ICD shocks and there was no significant difference in the mortality rate, however, if you look to the absolute numbers you can see that six out of the patient population with ablation died over time versus 11 patients who died when they had the ICD only. So there was a trend, there was a tendency towards a lower mortality in the ablation group, however, this study was not powered to look into this. Now the European trial, the VTACH trial, showed also a significant benefit for the patients undergoing catheter ablation in addition to the ICD. These are the black columns, these are the median values and the mean values for the time from ICD implant to the first VT/VF. And as you can see, there was a significant reduction from 18 months to six months as the median value and 16 to 11 months as the mean value. Interestingly, when we look to the time from the ICD implant to the first VT/VF from the Kaplan-Meier curves, you could also see the clinical benefit for patients that underwent catheter ablation. However in
contrast to the US trial and patients with unstable VT/VF, this patient population had a significantly higher recurrence rate for both the control group as well as for the ablation group. In this trial, despite the fact that there was a significant prolongation of the time to the first VT/VF when the patients underwent catheter ablation in addition to ICD implantation. But that benefit could only be demonstrated for patients with an ejection fraction above 30 percent whereas in patients with an ejection fraction below 30 percent no difference was found in the time from ICD implant to first VT/VF for this patient population. Now to answer the question what is the optimal time should we wait until patients have multiple shocks and several drug trials or should we intervene at a time when the patient is haemodinamically stable, which is at the time when the patient does not have any single episode of a VT/VF that has led to an ICD intervention. So on one side you have patients that are often transferred such as an electrical storm or after multiple shocks and these patients quite often are haemodinamically unstable or what you should do the ablation when the patient is rather stable. Now of course there is no direct comparison of these two strategies but if you look to the data that come from the three big non-randomized trials, you think cooled RF energy. You can see that the incidence of procedure related death is ranging in the three trials from zero to three percent. The major complication rate is ranging from 3.6 to 10 percent and these are the published data of the three trials. Now if you compare these two numbers to the numbers of the two studies that did catheter ablation prophylectically at a time when the patient was stable did not have had a single ICD intervention, you see that there was a zero mortality rate in the two trialsm, the randomized trials. And the major complication rate was clearly lower. I wouldn t say significantly lower because of course, the numbers are too small but if you compare again to the three studies after multiple shocks, there 3.6 to 10 percent and here 3.8 to 4.7 percent. So it could give us a hypothesis to believe that if patients do undergo catheter ablation at a stable point in time, that the death rate which is related to the procedure, the mobility rate related to the procedure may be lower and that this could be an argument not to wait until the patients really are in bad haemodynamic conditions. So in conclusion Mister Chairman, ladies and gentlemen, despite the fact that the ICD is the mainstay of therapy to prevent sudden cardiac death in VT/VF patients, catheter ablation of VT at any point in time reduces the number of ICD interventions, also, if used prophylactically, however for this indication we definitely need more studies to confirm the results of these two randomized trials. It may improve prognosis in selected patients and has been shown for patients with electrical storm and still the time for catheter ablation is unclear but it looks like, and it s not only the feeling, it s also coming from the safety data of the randomized and non-randomized trial that an earlier referral for catheter ablation may be better for these patients than the late referral of the multiple shocks. Thank you very much for your attention.