- This is Dr Angelo Auricchio, I am the Director of Cardiac Electrophysiology at Istituto Cardiocentro Ticino in Lugano, Switzerland. It is my distinguished honour and privilege to welcome you to the first podcast of Cardiovascular Implantable Electronic Device Infection series. We will start from the basics. What is a cardiovascular implantable electronic device? I invited Dr Archie Rao, Clinical Lead and Consultant Cardiologist in the Liverpool Heart and Chest hospital in UK who has done research on the gap in knowledge on device infection and she's very committed to increase awareness. Both of us treated patients with devices, and we also treat patients with infected devices. Thank you very much, Dr Rao, for accepting my invitation. Welcome.

- Thank you so much, Angelo. I look forward to the next 10 minutes of our conversation.

- This is good. So, Archie, to start with, may you probably tell us what is a cardiovascular implantable electronic device in a very short description?

- So CIEDs are a class of medical devices used broadly to manage patients with slow heartbeats or fast heartbeats. They can also be used in the treatment of selected patients with heart failure.

- Oh, great. And so, you say, but why are patients implanted with a device like this one? It is really needed?

- So the CIEDs have the ability to fill in the gaps in patients' heart rates. So with the use of the technology, they're able to prevent the pauses that patients have. They're also able to treat tachycardias, or rapid racing heartbeats, and even more interestingly, they treat selective patients with heart failure by synchronising the ventricles, the chambers of the heart.

- So and do the patients feel a benefit or they do have improved life?

- Indeed, absolutely. I think patients feel better, they live longer, they have fewer hospitalisations, and, by and large, are so much better for having a CIED in situ.

- Okay. So you are talking very broadly of CIED, so it seems to be quite different types, so large variety of devices we have, but probably may you help us understanding which are the differences between them, but also how patients benefit from them or from each of them?

- Sure. So CIEDs is a general term for a large number of devices, as you said, they include permanent pacemakers, they include implantable defibrillators, or ICDs in short, and cardiac resynchronisation therapy devices. CRTs also in some parts of the world known as biventricular devices. So pacemakers, as mentioned, are very much there to treat slow heartbeats. Defibrillators are there predominantly to treat rapid-racing heartbeats or life-threatening arrhythmias. And the cardiac resynchronisation therapy devices are there to synchronise the ventricles in patients with heart failure, thus improving morbidity and mortality in all these classes of patients. These devices are generally implanted under the skin with the leads threaded down a vein to connect to the heart. These are the traditional CIEDs. There is of course a new generation of CIEDs that have precluded the need to access the vascular space. So either implantation of these devices without leads, or leadless devices, or use of leads within the extravascular space.

- Excellent. And the use of these leadless or transvenous devices is right similar, right?

- Indeed, the leadless devices are in a relatively new stage. So the remit of the leadless devices currently is very much for pacemakers to try and improve heart rates. We haven't gotten in to in the mainstream using them for the heart failure population, and the defibrillators, the leadless type, or the extravascular types are currently in use as well.

- Excellent. So, if I understand exactly what you're saying is that CIEDs are essential devices, really lifesaving for patients, but also making their life better. But I may think that when you implant a device like this, you may have potential complications, right? So it can be acute complication or even during the time or during the time that the patients is living with the device, he may or she may have experienced complications. So is this something that you also see in your patients?

- Of course. It is, however, really important to remember that, by and large, CIED implants are a safe procedure, very much designed to improve prognosis, morbidity and reduce mortality for the patient. That said, we can encounter both early and late complications during the implant of a CIED. So the early complications are often very procedural, by which I mean these happen whilst the patient is still in hospital often, having undergone the CIED implant. The most common of these are related to bleeding, what we call around the pocket, called a pocket hematoma. We can have lead displacement, which means that the leads don't stay where the operator has left them, which might necessitate another procedure for the patient. So we have to go back in and reposition the leads. It may be to do with the vascular access. So when we try and find the vein from under the lung around the clavicle, we can cause a deflated lung, commonly known as a pneumothorax, or it could be to do with bleeding around the heart, related to the screw on the lead or positioning of the lead.

- I see.

- These are, of course, happen very procedurally, so they're often picked up and managed very effectively at the time of the implant, or around the time of the implant. A dreaded complication, of course, is one of device infection. And the tragedy of this is that it can happen very procedurally around the time of the implant as an early complication, but it can also occur remote to the implant. So at a much later stage. And this makes it very difficult, because the prognosis of patients with device infection, untreated device infection is very poor, and in some ways it takes away the benefits of the CIED when this is not managed properly. These device infections need to be picked up promptly and treated effectively. The prompt treatment of these devices entails antibiotics, but also a complete removal of the hardware of the CIED.

- This is excellent, what you say, Dr Rao, very, very informative. So essentially you're saying that CIED infection may occur, say at the time, or around the time of implantation, but more and more frequently eventually during the follow-up of these patients. And now the question is, is the level of severity of a complication is the same or you may consider the one coming later, it is more serious than the one coming early on?

- That's a really interesting question, Angelo, and I think it's a difficult one to answer. I would argue that the ones that are periprocedural, or early complications, particularly with CIED infection, are picked up more easily because they're often related to the pocket itself, and because they're picked up easily, they're managed better, and because they're managed better, the prognosis of these patients is better. On the other hand, the remote patients who have remote CIED infection from the index implant procedure are less likely to be identified, less likely to be treated, and therefore have a much worse prognosis. Recent data emerging from the the Duke Heart Centre suggests that the median time for detection of infection was 3.7 years after implant. And as a consequence, few patients were actually managed, less than one in five patients actually were managed as per the guidelines.

- Oh, wow. That is really important. But now you say in general the number of patients treated with an ICD, oh, sorry, with a cardiovascular implantable electronic devices are increasing, right? Because now we have a much broader spectrum of disease that can be treated by a CIED. So meaning that also the proportion or the rate of infection probably may increase as well, right? So we should see more patients or more frequently in our clinical practice, this kind of a patient.

- Absolutely, absolutely. As the complexity of the device patient increases, as we put more complex devices in frailer, older patients, there is little doubt that the patient factors and the device-related factors will result in the incidence of infection increasing. Indeed, the Duke data that I was referring to earlier suggests that the incidence of infection across all new CIED implants was just over one to 2%. But of course we know from other historic data across Europe, is that the infection risk is much higher when you re-intervene on pockets, and a vast proportion, up to a third of current CIED procedures undertaken, are for either battery exchanges, or for things like upgrades, are re-interventions in pockets, and this carries a three to 4% risk of infection.

- Oh, wow. So, but meaning that, essentially, there is probably the perception that patients with CIED, probably they are doing well, but then suddenly they pop up in an outpatients clinic or in an internal medicine department. So essentially in non-cardiology department, and there the question is do you believe that our colleague are also particularly able to pick early signs of infection or you have the impression that probably there is an underestimation and, of course, an underdiagnose of CIED infection?

- I think this is a really important issue, Angelo, the fact that this is a heterogeneous population, and they present in diverse ways. Some of them present with a pocket infection, some of them present with pyrexia of unknown origin, and to different places, to accidents and emergency departments, to internal medicine departments. It's really hard. The index of suspicion is key, I believe, in picking up CIED infection.

- So, wow, this was really great, Dr Rao, thank you very, very much for the discussion, it was really a great overview of what today some potential issue is related to device infection. And, by the way, I think device infection is a treatable state. So essentially we may use different type of therapy starting with antibiotics, but really ending with lead extraction or device and lead extraction. Having discussed the complication of CIED infection and, of course, the fact that this may be treated, I think the following episode will zoom on early detection of infection, and I really recommend you don't miss our next podcast, or visit the website, deviceinfection.com. Thank you very much for staying with us, and thank you Dr Rao, again.