COMMENTARY

TAVR for the Referring Physician

Seth Bilazarian, MD; Jeffrey J. Popma, MD

Disclosures

May 19, 2014

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Now What Do We Do?

Seth Bilazarian, MD: Hi. This is Seth Bilazarian, at the American College of Cardiology (ACC) Scientific Session in Washington, DC. I am very excited to be able to sit down with Dr. Jeffrey Popma, Professor of Medicine at Harvard Medical School and Director of Interventional Cardiology at Beth Israel Deaconess Medical Center.

Most important, for our conversation today, Dr. Popma was a co-principal investigator for the CoreValve trial, the high-risk subset of which was presented here.[1] It has made a lot of news. There's a lot of excitement about it. It has been published in the New England Journal of Medicine.[2]

I am going to ask Dr. Popma a few questions. Dr. Popma has been going all day. I saw him first at 5:45 this morning, when he did another debrief of the data. He has worked very hard to get these data. This was the first trial to show a mortality benefit with transcatheter aortic valve replacement (TAVR) compared with surgical aortic valve replacement (SAVR).

I was hoping to grab Dr. Popma or corner him on an escalator and ask him a series of questions, and I'm sure others are in the same position. As Jeff was presenting today, I was thinking of the movie called "The Candidate" that stars Robert Redford. There is a famous line at the end of the movie after Robert Redford does all of this work to become elected. The final question is, "Now what do we do?" The question is never answered.

I have been in practice for 21 years. I have taken care of many SAVR patients. I think I understand how to do it. We have new valvular heart disease guidelines[3] from ACC/American Heart Association (AHA). We have recommendations on echo follow-up and antithrombotic therapies. I referred 29 patients for TAVR from the PARTNER trial[4] onward. A couple of days ago, I sent you an octogenarian. I have been sending patients, and now we are getting patients back after the commercial release of the Edwards Sapien valve and the CoreValve.

The TAVR vs SAVR Patient

Dr. Bilazarian: I have a series of questions. The overall theme is: How are TAVR patients different from SAVR patients? Are there particular nuances that we should pay attention to ("we" being the community cardiologists who refer patients to excellent centers, such as yours) in taking care of these patients?

Jeffrey J. Popma, MD: Thanks for having me. That is an amazingly provocative question. I have been thinking about exactly how to respond to that since you first brought it up. It's an unmet need. We haven't done this the way that we should have done this in the community.

Let me give you some thoughts. First of all, the reason that the patients have been candidates for TAVR is that they are either not operative candidates (extreme risk), or they are at increased risk for SAVR as assessed by a surgeon. To get into that pool, these patients carry with them a variety of different comorbid conditions, frailties, and disabilities that, quite frankly, internal medicine and geriatricians have been taking care of for a long time.

As a structuralist who manages patients with aortic valve disease in this category, over the past 3 years I have become more of a geriatrician in my management skills. You have to think about every detail. You have to look at every piece of the patient's history, because it is incorporated into how you manage them afterward. In many ways, I have become a better doctor.

In returning these patients to the community, as you have pointed out -- when they are not part of a research study where we follow them at 1 month and 6 months and 1 year and yearly thereafter, they are going back to the community now, with their daily diseases and their daily comorbid conditions.

Postprocedural Cardiac Changes: What to Expect

The moment that the aortic valve stenosis is relieved, the heart begins to get better, but there is a regression of left ventricular wall mass that occurs over 6 months. That means that most patients present with severe diastolic dysfunction. The day after we manage them and relieve their aortic stenosis, they still have diastolic dysfunction. During that 1-month period between when we discharge the patient and when they come back for their early follow-up, they are often still dyspneic.

Dr. Bilazarian: They are clearly dissatisfied.

Dr. Popma: They are getting better, and they are thrilled that they made it through the procedure, but we still need heart failure management. We need heart failure management with diuretics and angiotensin-converting enzyme (ACE) inhibitors, and they need very close surveillance. It's not uncommon in the first couple of weeks, particularly in these very frail patients, to bounce back in the hospital because of an episode of diastolic dysfunction and heart failure. That will get better at 1 month. It will be even better at 1 year. When we see the patients at 6 months, they feel pretty good.

The second thing that I have noticed is that when we relieve the aortic stenosis, now the ventricle unloads its entire volume to the aortic system, and they have hypertension. A key feature when we do this transition is managing hypertension.

These patients are elderly. They have been on other medicines. They have to be managed. They can tolerate a little bit higher blood pressure, but they really should not be managed at 160, 170, or 180 mm Hg systolic pressures. We should try to bring them down.

ACE inhibitors are one way, and calcium-channel blockers are another way. Beta-blockers are sometimes tough in these patients because of a variety of different issues, so we try to use other agents. Sometimes you have to put them on a solid afterload-reducing agent.

The third thing is that they need to move. This very elderly population of patients (and when we started out, we actually did a lot of patients who were wheelchair-bound) needs to move. Everything that we can do together to encourage them to increase their activity, even with cardiac rehabilitation, is the right thing to do for them. Those are just some initial thoughts.

How Close Should We Follow Them?

Dr. Bilazarian: Let me ask some general questions that are more pointed, if I could. The new valvular heart disease guidelines just came out, and there are very few references to TAVR. They recommend echocardiogram follow-up for the SAVR patients early, and then only if clinical symptoms occur; otherwise, at 10 years.

Those are the recommendations for SAVR patients. They are pretty reasonable recommendations, and it is probably less than most patients are getting post-SAVR. What would be the recommendation for a TAVR patient?

Dr. Popma: That's an excellent question. A lot of it is initial discussion with the proceduralist. The major thing that we are looking for is perivalvular regurgitation. It doesn't matter which device you're talking about -- balloon-expandable, self-expanding -- we look for perivalvular regurgitation. It turns out that in some patients, it regresses and stays the same. Some people will get worse.

It's probably reasonable a month or so after the procedure to get an echocardiogram and just make sure that there is no perivalvular regurgitation and that left ventricular function is normal. With significant degrees of perivalvular regurgitation, what would trigger me to think about doing something more is if the ejection fraction dropped or if the patient was starting to complain of more heart failure.

Any time that a patient presents with new symptoms is a good time to take a look. Otherwise, a month is a reasonable time. I don't see much change in the echocardiograms between 1 and 6 months. That is where we measure in the study protocol. Doing another echocardiogram a year later just to assess valve function (because these are new) as well as to assess for perivalvular regurgitation is a good idea.

With respect to longer-term follow-up: Remember, these devices are new. We haven't been following them for 10-15 years. Some of the comfort that we had about not following surgical valves was because the surgical valves were available for 30 years, and we knew how they performed. We are still learning that with the transcatheter valves. I would have a high threshold for another echocardiogram if the patient's symptoms did not change much.

We do know (at least out to 4 years now) that the valve grade has remained low, and that there is no early restenosis within the valves. That is reassuring.

What About Dual-Antiplatelet Therapy?

Dr. Bilazarian: The valvular heart disease guidelines say that it is a class IIb recommendation for patients to be on clopidogrel for 6 months and aspirin indefinitely after TAVR. As a community-based cardiologist, how should I think about this? I know how to think about dual-antiplatelet therapy (DAPT) for drug-eluting stents (DES). How should I think about this for the patient who may have an episode of gastrointestinal bleeding? How important is DAPT? I'm going to follow this up with an atrial fibrillation question.

Dr. Popma: I'm going to leave out the atrial fibrillation and just deal with the DAPT with sinus rhythm. The guidelines were based on the PARTNER protocols that said 6 months of DAPT. We used 3 months of DAPT in the CoreValve study; aspirin and clopidogrel for 3 months, and then aspirin indefinitely. It was a slightly shorter duration of DAPT.

The problem is that these patients are elderly, and sometimes they can't tolerate it. It's not uncommon for patients to have gastrointestinal bleeding, or for some other reason, we have to stop the DAPT. And that's okay.

Dr. Bilazarian: It's a lighter recommendation than for DES.

Dr. Popma: Absolutely, because it's more of a recommendation that has carried through the initial implant saying that we should do something. I don't know that we really have evidence for it. There is a randomized trial going on right now of DAPT vs monotherapy. Clopidogrel may not be the right drug. You are getting into the atrial fibrillation catch.

The major thing that we worry about is thrombus: either thrombus for stroke and the small percentage of patients who develop a stroke afterward, or thrombus around the valve. The guidelines even suggest anticoagulation therapy for surgical valves for a short duration. We don't do that, but maybe we should do that, because these are newer.

If I were going to make a sea change in my practice, it would be considering going to aspirin and warfarin, rather than aspirin and clopidogrel. But that decision is made easier if the patient has underlying atrial fibrillation or paroxysmal atrial fibrillation; then aspirin and warfarin is the right combination without clopidogrel.

Should We Worry About Atrial Fibrillation?

Dr. Bilazarian: Now to the last question. What every patient worries about in this age group is not death. We all know that. The only thing that they worry about is stroke. We see that there is an incidence of stroke with SAVR and TAVR. Unfortunately, we see that there is a gentle increase even after successful TAVR over the first year, which is something that we would love to make an impact on.

We also know that as much as 40% of the patients in these trials have atrial fibrillation. Frequently, patients have silent atrial fibrillation that may be causative in strokes, but we haven't yet picked it up.

What should we do? Should we be more sensitive? Should we do something more? Our patients complain about palpitations. If they aren't bothersome, we say, "Don't worry about it." Should we be doing more Holter monitoring? Should we be more vigorous? Should we use anticoagulation earlier? I will also ask about novel oral anticoagulants.

Dr. Popma: That is a broad set of topics. Let's talk about stroke for a second. It's the old adage: If you look for it, you will find it.

In our high-risk trial, everyone had before-and-after neurologic examinations. Any abnormality in the neurologic examination or in the National Institutes of Health (NIH) Stroke Scale triggered a neurology consult and imaging. We used very strict criteria per the Valve Academic Research Consortium. If a defect lasted for more than 24 hours, it was a stroke. If it was less than 24 hours, but there was an imaging study, it was a stroke.

We had very good ascertainment of stroke in our study, which means that we found a lot of strokes that we would have otherwise missed. As it turns out, what we found out for all strokes (both major and minor) was that rather than being higher than surgery, stroke in TAVR was actually a little bit lower than surgery. It didn't reach statistical significance (P was 0.1 at 1 year). When you look at the curves, SAVR patients had strokes and TAVR patients had strokes, but fortunately, it wasn't the same event rate that we saw in other studies. It was actually a little bit lower. We don't want anybody to have strokes. We found that postoperatively, 30% of the patients had new-onset atrial fibrillation after SAVR.

In general, the surgeons wait. They give warfarin. They don't give heparin. There may have been some stroke early on that we didn't pick up. When I have TAVR patients who have paroxysmal atrial fibrillation, as soon as the groin is dry, I start heparin. I bridge them from heparin to warfarin.

Maybe we were very smart in terms of how we managed atrial fibrillation, but aspirin and warfarin are the right way to go. I agree with you. It's probably an underappreciated cause of stroke, particularly when it occurs after the procedure.

The good news for patients is that we think these rates are coming down, and the devices are becoming lower-profile. We are a little bit more gentle with the procedure. For example, with the CoreValve, we are avoiding the predilatation rapid ventricular pacing most of the time now, and just not doing that additional trauma to the valve itself.

We are really evolving this technique. The stroke rates are coming down. They are not yet zero. It will come down to whether we think we should invest in embolic protection devices to try to correct the carotids and protect the vertebrals. A variety of companies are coming up with new tools for that.

Dr. Bilazarian: We have to stop, even though I have many more questions. Thank you, Dr. Jeffrey Popma, for joining me to summarize some concerns in the clinical community about how we should go ahead. Of course, I knew that the answer would be, "We're not sure yet," but I hear you saying basically that we should watch these patients a little more carefully than our SAVR patients, but for the time being not much different from that.

Dr. Popma: Perfect. Thanks, Seth.

Dr. Bilazarian: Thank you very much. From Washington, DC, at the ACC, thanks for joining us.

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