Pacemakers & ICDs: When to Get Them and What to do if You Need to Remove Them

Podcast Transcript

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Oussama Wazni, MD:
All right. Good morning, everyone. And welcome once more to another podcast from the EP section here at the Cleveland Clinic. As you know, I'm Oussama Wazni. I'm the section head of the section at the Clinic. Today, I have with me Dr. Wilkoff, who is the director of electrical therapies at the Clinic. So basically, he's the director of everything devices. And also, Dr. Tom Callahan, who is the director of the in-hospital services. So any patients who get admitted to our service, Dr. Callahan is the one who is responsible for their overall care while they're here in the hospital.

Oussama Wazni, MD:
Today, we're going to be talking about devices, the indications to implant the device, indications to extract or remove a device, and how we do that in most cases. So good morning, and welcome to both of you.

Bruce Wilkoff, MD:
Good morning.

Thomas Callahan, MD:
Thank you. It's great to be here.

Oussama Wazni, MD:
All right. Let's start with Dr. Callahan. Dr. Callahan, so what are the indications? When does a patient need a device, whether it's a pacemaker or defibrillator?

Thomas Callahan, MD:
Yeah, that's a great question. I will start with pacemakers. I think one of the common misconceptions about pacemakers is that it completely controls the heart rhythm, and really that's not the case. What a pacemaker is able to do is keep the heart from going too slow, so the typical indications for a pacemaker are when the heart rhythm is too slow. And broadly, the reasons for a heart rhythm going too slow can be broken up to problems with the AV node, that's the electrical connection between the top and bottom chambers, or the sinus node, that's like the natural pacemaker of the heart. If a patient's having problems with the AV node, very often that can become serious somewhat quickly. So pacemakers can be placed for AV node issues, generally speaking, even if the patient doesn't have symptoms. The physician needs to take a look, really gauge the severity of the AV node dysfunction, and then make a decision as to whether a pacemaker's indicated.

Thomas Callahan, MD:
On the other hand, sinus node dysfunction, that natural pacemaker of the heart, usually that is not something that becomes very serious very quickly. And so we place pacemakers for sinus node dysfunction really only if the patient's having symptoms. So if they're feeling fatigued, they're not able to exercise to the degree that they feel they should be able to, that's when we would consider a pacemaker for sinus node dysfunction.

Oussama Wazni, MD:
Very good. Very good. So basically, in a nutshell, pacemakers are for patients who have slow heart rates.

Thomas Callahan, MD:
Yeah, exactly.

Oussama Wazni, MD:
The doctor will decide whether it's because of the sinus node or the AV node. Dr. Wilkoff, how about the defibrillators?

Bruce Wilkoff, MD:
Implantable defibrillators have a pacemaker in them, at least most of them do. So they do protect against slow heart rhythms, but their primarily placed to treat people who might have a very rapid heart rhythm, usually called ventricular tachycardia or ventricular fibrillation. This causes a syndrome called sudden cardiac death where people suddenly pass out and if not revived would die. Now, it is possible to rescue a person with CPR and external defibrillation, usually through an emergency squad of some sort. But that's not as effective as we'd like it to be, because it has to be done so quickly. It has to be done within about about 10 minutes. And if not, then that person ultimately dies. But if you put in a special device that has the pacemaker and the defibrillator, it can respond within seconds, really moments, and return that person to normal rhythm, make them awake and without any problems, maybe not even know that they had tachycardia, using either the pacemaker or a shock.

Oussama Wazni, MD:
So who are the patients who are at risk for the ventricular tachycardia and sudden cardiac death?

Bruce Wilkoff, MD:
Well, most of the patients will fall into one of two categories, either people with coronary disease or people without coronary disease. And most of those patients have what we call heart failure or left ventricular dysfunction, or just a bad pumping function of their heart because of the scar on their heart. That puts them at risk for tachycardia. There are some other reasons, some genetic reasons for defibrillators as well.

Oussama Wazni, MD:
So basically to simplify it, it's for patients who have poor pumping in the ventricle. There is a number, something we refer to as the ejection fraction. If it gets too low, usually 35% or less, that puts patients at risk. So a defibrillator is indicated in those patients, or patients who've already had sudden cardiac death, but they were lucky and they were saved, then they would get a defibrillator.

Bruce Wilkoff, MD:
That's also true.

Oussama Wazni, MD:
Perfect. Now, we have implanted a pacemaker or a defibrillator in a patient, but they can develop some issues that may need a revision which may entail removal of a lead, or they have some other issues that need us to take out the devices. We refer to this as extraction. So I'm going to start with Dr. Callahan. In broad terms, what are the indications, or when does a patient need an extraction?

Thomas Callahan, MD:
That's a great question. There are a number of indications for lead extraction. The primary reasons for lead extraction are probably lead or device infection. So in rare cases, pacemakers and defibrillators, their leads can become infected or involved in a broader infection. So that's one broad category that would often or typically require a pacemaker or lead extraction. And then the other broad category that accounts for most of the extraction is dysfunction. So if the pacemaker or defibrillator lead is not functioning properly, then very often an extraction is done to remove the lead so that it can be replaced with another lead. And then other categories that they fall in, sometimes people have problems with the veins through which these leads travel, and then we might do an extraction for some of those patients. Or perhaps they're having a device that's being upgraded from a pacemaker to a defibrillator. So there are some other indications, but broadly most patients are going to fall into the infectious category or some sort of a lead dysfunction category.

Oussama Wazni, MD:
Very good. Thank you so much. Now, Dr. Wilkoff, could you tell us more about what the extraction procedure entails? Where is it performed and why? What does it take to perform a successful, safe extraction?

Bruce Wilkoff, MD:
Well, it's been under development for quite some time, probably started back in the 1980s, even though pacemakers have been put in since the late 1950s. But it became clear that anything that is created can also break, and any process needs some maintenance. This is the maintenance process. We therefore call it lead management, because we have to manage the patient and the leads and their needs over a long period of time.

Bruce Wilkoff, MD:
We first try to make sure that it's indicated, because once we try to take these leads out ... They heal in place. When they're first inserted, they go through the veins that Dr. Callahan was talking about, and they sort of slide through. They take those pathways like roads, but then they heal in place. If you were to pull on them, they would pull on the veins or pull on the heart. If you would just yank on them, then it might rip the vein or the heart. But it is possible to carefully dissect away the leads from the vein and the heart if you take proper precautions.

Bruce Wilkoff, MD:
The proper precautions are to have a whole evaluation where you get a chest X-ray, maybe a CT scan, an echocardiogram. Those types of things, but also consulting with a cardiothoracic surgeon, anesthesia, making it so that we know that if there's a problem, that we can deal with that problem. We prep the patient knowing that over 98% of those patients will have no problem, but in that small percentage, an emergency can occur. There can be internal bleeding. We need to be prepared, so we are. We do it in a special room called a hybrid operating room. The hybrid operating room is both an operating room for cardiothoracic surgery and a cath lab, so a hybrid between the two situations. And we have everything that cardiovascular medicine has to offer available in that room, and all the people and the big team that's trained specifically for that circumstance.

Oussama Wazni, MD:
That's excellent.

Thomas Callahan, MD:
Dr. Wazni, if I can?

Oussama Wazni, MD:
Yeah.

Thomas Callahan, MD:
I just want to piggyback on Dr. Wilkoff's comments. Pacemakers and defibrillators, there's been so much advancement in the technology and the leads they've become incredibly safe and reliable. But to Dr. Wilkoff's point, most of these patients, the reason we're placing these devices is so they can live very normal lives, and they live for decades. So over decades, then patients can start to develop some of these issues where a lead will need to be replaced and so forth. I think it's important to note that this is something that we have to manage as Dr. Wilkoff said, but it's typically something that we watch over the course of decades.

Oussama Wazni, MD:
So the occurrence of a complication is really very, very rare. In our experience, probably it's 2% or less. But the good news is that we're in the hybrid OR, and we have surgeons to back us up. If a complication were to happen, the surgeons will come in and they will fix that problem. So how has our experience been in regards to a salvage or saving a patient if this happens, Dr. Wilkoff?

Bruce Wilkoff, MD:
Just to be very plain, people can die from this procedure if you don't respond appropriately. We're talking about a tear in the vein that bleeds internally and needs to be repaired. Some people could die, so we want to make that as infrequent. A complication is one thing, but death is quite something else.

Bruce Wilkoff, MD:
We have provided for some new tools. We've been working at this. What we do is we put a guide wire from the leg vein, up to the neck, and we have this special pillow-like balloon that we put up in the area where that's most vulnerable. That can temporize. It can temporarily protect the patient from excessive bleeding so the surgeon can, in a more controlled fashion, open up the chest. But that's what has to happen. The chest has to open, the surgeon has to go and find out where the leak is coming, and then sew it up. Sometimes we use a patch. But generally speaking, that goes quite well, but it is a very specialized type of a procedure, and we have the best surgeons in the world here at the Cleveland Clinic that assist us. We work in a collaborative fashion. We work together.

Oussama Wazni, MD:
Excellent. So our rescue efforts have been fantastic in our outcomes when this happens, which is very rare. Again, it's very rare to happen. But when it happens, the rescue operation has been, on the most part, very, very successful. That's the good news from that standpoint.

Thomas Callahan, MD:
Yeah, I think ...

Bruce Wilkoff, MD:
Dr. Wazni ... Oh, go ahead.

Thomas Callahan, MD:
No, I was just going to say looking at national statistics, I think the risk of death with a lead extraction is less than a percent. But when we sort of dial down on that, the rescue, or the risk of death with a lead extraction here at the Clinic has been, I think, less than half of what the national average has been. So we're very fortunate to have the resources and the excellent surgeons and the planning to make this a very safe procedure here.

Oussama Wazni, MD:
So for the patient, just so that we can get the message to our patients. Again, we want to thank our patients for listening to us. What is it that they look for, or how would they know that they have an infection or a lead dysfunction? So to either of you, any one of you can answer this. What are those things that would indicate that maybe there's an infection or there is a lead dysfunction?

Bruce Wilkoff, MD:
The first thing is that patients who have an implantable device, whether it's a pacemaker or defibrillator need follow-up. That's done mostly remotely, but it's important that the patient comes to see the doctor on a regular basis, at least once a year. The measurements, whether the remote from the patient's home or in-person, take the information from the pacemaker device. It tells us about the battery, the leads, the heart rhythm, how it's functioning, and all of these diagnostics. All of this information flows into the computer system, and then displayed back to the patient and to the doctors and such like that. So that's how we know how the patient is doing. That plus the patient's symptoms. If the patient has symptoms, they have to let us know. If we see something, we let the patients know.

Oussama Wazni, MD:
So basically, for lead this function, it's really based on the system telling us this information. Most of the time, hopefully, this information we get before the patient develops a symptom because of lead dysfunction, because some of the dysfunction can cause to shocks or inappropriate pacing or no pacing, and the patient can have symptoms. Now, with respect to infection, Dr. Callahan, what are the things that patients can look for or things that can indicate that maybe there is an infection that involves the device?

Thomas Callahan, MD:
Right. Infection can be subtle. It can be sneaky, but very often it's something that the patient will note first. It's something that the patients will come and talk to their physician saying that they've identified a problem. So infection can broadly be broken up into a local infection, meaning infection around the actual pacemaker or defibrillator, or something that's more systemic, like an infection that involves the leads or even the heart where the leads kind of connect to the heart.

Thomas Callahan, MD:
Typical symptoms that patients will will identify at the site would be redness, swelling, increasing pain at the site. We often will see some swelling, some redness immediately after implantation or a generator change, but those things typically will get better over the course of weeks. So if suddenly things are getting worse, a patient seeing more swelling, more redness, more pain, that would be something that would be certainly worth a phone call or a conversation with their physician. Lead or the systemic infections will typically present with fever, chills, night sweats. Sometimes just a general sense of not feeling well, or nausea or vomiting. So it's-

Oussama Wazni, MD:
That would be more along the lines of a bloodstream infection.

Thomas Callahan, MD:
Exactly. Exactly. Yeah. Right.

Oussama Wazni, MD:
Because if the patient has a device and is admitted to another hospital, for example, with a bloodstream infection, then the patient and the team should be worried about an infection that is probably involving the leads. So that's a bloodstream infection, correct?

Thomas Callahan, MD:
That's correct. Yeah, that's correct.

Oussama Wazni, MD:
All right. So what are the things that we do? Since we're now on the infection topic, what are some of the things that we can do to decrease the risk of infection? Dr. Callahan first with regards to things that we do when we're implanting.

Thomas Callahan, MD:
Sure.

Oussama Wazni, MD:
And then we'll talk to Dr. Wilkoff and the new technology that we're going to talk about.

Thomas Callahan, MD:
Sure. I mean, broadly, a pacemaker is placed in a sterile operating room using sterile technique. That's probably one of the most important things, real careful attention to sterile technique. That starts from the patient preparation, all the way through the actual surgery itself. We also will typically use IV antibiotics for patients, and that's been shown to decrease the risk of infection. There are some other measures. We irrigate the pocket with antibiotic solution and so forth. It's thought to decrease infection rates. But really, the most important part is that sterile technique, starting from the patient preparation, all the way through the closure.

Oussama Wazni, MD:
And then new development, Dr. Wilkoff, to decrease device infection or pocket infections.

Bruce Wilkoff, MD:
Sure. Well, one thing that should be said is the time of the most likely introduction of the bacteria is at the time of the surgery, so what Dr. Callahan said was primal. It is the most important thing, sterile technique. But there are bacteria on the skin, there are bacteria in the air, and so some contamination can happen. Some of the bacteria have what's called a biofilm, and they're a little sticky, so the pacemaker and the leads are sort of vulnerable to a slow growing infection. So at the time of a surgery, nothing may be apparent. But a month, six months, a year, two years, even three years later, that's when you can see the changes in the pockets, and it's very important.

Bruce Wilkoff, MD:
The object is to reduce the burden of that contamination, and so we have what's called a resorbable antibiotic envelope. I and Dr. Tarakji, other one of my partners, did a worldwide clinical trial of this resorbable, or absorbable, antibiotic envelope that has antibiotics that lasts for about a week, maybe a little longer. The envelope itself absorbs into the body within three months, but it reduces the rate of infection by about 50%. Every infection is important because the consequences of the infection, as Dr. Callahan was saying, is that we need to do an extraction, and the consequences of infection is that there's a risk of dying. There's a risk of other bad consequences to the infection. That means that we should avoid it. It's expensive, and it's uncomfortable. There's a lot of reason to do that. But these envelopes, plus the antibiotics now with ... We enrolled about 7,000 patients in this worldwide trial. It's the largest clinical trial ever done in implantable devices, and has proven that we can reduce infection for the first time.

Thomas Callahan, MD:
Yeah, I think-

Oussama Wazni, MD:
We can reduce infection over and above what we already had, which was a low percentage, but still it can be lowered even more with using the envelope.

Bruce Wilkoff, MD:
Absolutely.

Thomas Callahan, MD:
The work that Dr. Wilkoff and Dr. Tarakji, and the work that was sort of spearheaded here, the importance can't be overstated. I mean, in medicine we find significance if a therapy reduces a bad outcome by, say, 10 or 15%. So reducing the risk of infection with devices by close to 50%, that's huge. It really can't be overstated.

Oussama Wazni, MD:
Just to put it in perspective, so what is the risk of a fresh implant? Meaning, the first time the patient is getting a device. What is the risk of an infection in that patient at our institution?

Bruce Wilkoff, MD:
So, it will depend upon the circumstances of the patient, how sick they are overall, whether they're on dialysis or whether the patient has just had a heart surgery, or things like that. But the overall first time implant infection rates should be less than a half of 1% for a first-time implant. But the lifetime risk of infection, because the battery will fail after a time as planned, the patient will need an upgrade to another kind of technology like a defibrillator or something we haven't talked about, resynchronization therapy, which helps for heart failure. In any case, these repeated operations provide for opportunity for repeated contaminations. So the lifetime risk of infection can be 15, 20, 25% over decades, so over many operations. The later you get into a person's life, the more the risk for an infection to occur, and more important that we have a way to reduce that.

Oussama Wazni, MD:
That's why the envelope is very important. Once again, this was fantastic work. A huge number of patients, and was published also in the most prestigious medical journal, The New England Journal of Medicine.

Oussama Wazni, MD:
Now, also we have had some new developments with new devices. I want to come to those right now. We'll start with Dr. Callahan. Tell us more about these defibrillators, that we don't have to go through the vein into the heart, the subcutaneous ones. And now, even more recently, the ones that go under the breastbone. So tell us about those, and when would those be indicated or when are they appropriate? And also, what is the advantage of such a device?

Thomas Callahan, MD:
Right. As we've discussed just previously, we know that patients have these devices are at some risk for infection. As time goes on, that cumulative risk can go up. There are devices, subcutaneous defibrillators and a newer device that kind of slides under the breastbone as you were indicating. The device is completely outside of the vascular system, outside of the heart. So while these devices can also become infected, the infection is usually not as serious. The consequences are not as serious because typically that infection can't get into the bloodstream, can't get to the heart. Also, most of the risk of removing these devices comes from removing the leads that are sort of scarred into the vasculature, scarred into the heart. So if one of these subcutaneous or other types of devices, these extravascular devices becomes infected, at least in theory, their risk of removal should be far less.

Oussama Wazni, MD:
Is much less. Right.

Thomas Callahan, MD:
So the indication for these typically are patients that don't need pacing. These extra vascular devices typically don't have the ability to pace, or are not able to pace continuously, so it's typically patients that don't need pacing, and often patients that we think may be at risk for infection. So patients that perhaps are on dialysis or have other high-risk features for infection, sometimes our younger patients where we think that cumulative risk is going to add up over decades. Those are the patients that we'll often think about for these extravascular defibrillators.

Oussama Wazni, MD:
Very good. Thank you. So in a nutshell, it's a patient who needs a defibrillator. We talked about this in the beginning. A patient who needs a defibrillator is one with a weak heart, at risk for sudden cardiac death or somebody who already had sudden cardiac death. We can implant a subcutaneous device if they don't need pacing. Now, if they need pacing, Dr. Wilkoff, we have some new developments also where we don't need to implant leads, and these are the leadless pacemakers. Can you tell us more about leadless pacemakers and why they are important?

Bruce Wilkoff, MD:
Well, at the beginning of the development of any technology, it usually is a bit simpler. These devices are a bit simpler, but they are also quite elegant because they're very small. They're a size of a jelly bean. They're put inside the right ventricle, the lower chamber of the heart, and there is no lead. And remarkably, they have batteries that last about a decade. So they're very sophisticated. They have a sensor that can change its rate with exercise. They can sense and pace normally in the ventricle. And now, there are some leads that can also synchronize to the atrium. It doesn't use the lead. It doesn't use electricity, but actually senses the contraction of the atrium and coordinates the contraction from the upper chamber of the atrium to the ventricle, the bottom chamber. So this is very exciting.

Bruce Wilkoff, MD:
We would like there to be, and there will be coming shortly, leadless pacemakers that are implanted in the atrium, can pace the atrium. There are now under investigation those types of leadless pacemakers, and leadless pacemakers that also can do cardiac resynchronization that can work for heart failure. But this beginning of development, and it's now well established for the ventricle, has become crucial for patients who have trouble. Their veins may have closed off. They may be at a high infection risk. These patients seem to be at much less infection risk and can be treated throughout the infection. It's a very exciting development.

Oussama Wazni, MD:
Yeah. And then just to clarify, these leadless pacemakers are implanted from the vein from the leg. So go from the leg, and they're not relying on veins from the arm or the shoulder in most cases.

Bruce Wilkoff, MD:
Yes, but there's nothing left in, except for this jelly bean sized piece of device.

Oussama Wazni, MD:
Exactly.

Oussama Wazni, MD:
We've come to the end of our time. This has been very exciting. So as you can see, ladies and gentlemen, our patients, there are a lot of exciting things going on. Pacemakers and defibrillators will be needed in patients, as we have discussed. These devices, as they stay longer in patients, may develop either infections or dysfunction. Here at the Clinic, we have the best teams to take care of these issues. And also at the Clinic, we are exploring new technology with subcutaneous defibrillators, leadless pacemakers that can now hopefully will be able to communicate with each other and even with defibrillators in the future so that we can minimize the use of the vascular system to get to the heart, and therefore decrease any risks associated with such a process.

Oussama Wazni, MD:
I want to thank both Dr. Wilkoff and Dr. Callahan for this fantastic podcast. I hope you will find it very useful and informative. Until we meet the next time. Thank you so much.

Bruce Wilkoff, MD:
Thank you.

Thomas Callahan, MD:
Thank you.

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