January/February 2012

Infection After Implant: Cardiac Devices Warrant Vigilance

By Lindsey Getz
Aging Well
Vol. 5 No. 1 P. 10

Although implantable cardiac devices save lives, associated infections warrant attention.

Cardiovascular implantable electronic devices (CIEDs) such as pacemakers and defibrillators are often lifesaving for patients with heart problems. Yet the development of infection following an implantation procedure can pose a life-threatening risk to these patients. With more patients receiving these devices than ever before and the rate of infection increasing rapidly, a closer look at the burden of infection and its impact on outcomes for patients living with cardiac devices warrants further consideration.

Though infection remains a rare complication, the concern lies in the fact that the rate of infection seems to be increasing at a faster pace than the rate of device implantation. While the number of cardiac devices being implanted has doubled since 1993, the number of associated infections has more than tripled, according to a recent study published in The Journal of the American College of Cardiology. During the time period examined in this retrospective study (1993 to 2008), more than 4.2 million such devices were implanted. The number of infections rose 210% over this 16-year span, from 2,660 cases in 1993 to 8,230 cases in 2008.

Though the exact reasons for this increase are unclear, it’s likely that increasing use of these devices in older and sicker patients is a driving factor. “I don’t want people to come away with the misconception that pacemakers and defibrillators are dangerous,” says Arnold J. Greenspon, MD, lead study author and a professor of medicine at Thomas Jefferson University Hospital in Philadelphia. “In fact, in the case of implantable defibrillators, there have been some studies that have shown they’re underutilized. The challenge is that we are putting these devices in sicker, older patients that have more comorbidities, so we need to develop strategies to minimize infection.”

Ronan Margey, MD, MRCPI, of Massachusetts General Hospital and Harvard Medical School in Boston, agrees. “Since people are living longer, the population is older and that means more heart disease—qualifying more people for these devices,” he says. “So overall, we’re implanting more devices than we ever did before, and they’re going into patients that are sicker and frailer to begin with. And since we’re looking at an older population with more comorbidities, the patients are more prone to complications. If they do develop infection, they may be less likely to overcome it.”

An Economic Burden
Though infection is always a risk with any invasive procedure, cardiac patients are especially vulnerable since they tend to be sicker in the first place. The rising rate of infections has tremendous economic implications for hospitals. These patients are likely to require prolonged hospital stays, and the related costs rack up fairly quickly. “The cost in treating infections is enormous,” says Greenspon. “Prolonged intravenous antibiotics, removing the hardware, and prolonged hospital stays all add up to a hefty price tag, and the cost we examined in the study only looked at the patients while they were still being hospitalized. It doesn’t even take into account the costs associated after the fact.”

In another recent study, published in the Archives of Internal Medicine, a link between CIED-associated infection and increased mortality and hospital care costs was further investigated. Depending on the CIED type, the adjusted length of stay was significantly longer for patients with infection. Authors noted that intensive care stays accounted for more than 40% of the incremental admission cost. Pharmacy services also contributed to a large portion of the cost.

“In terms of length of stay, we found that patients with device infections were in the hospital for at least one week longer than those who did not have infections,” says lead author M. Rizwan Sohail, MD, of the Mayo Clinic College of Medicine in Rochester, Minn. “The biggest cost in that one week is associated with their stay in ICU. Clearly, these patients had the devices implanted for important medical reasons, such as heart rhythm disorders and heart failure. Once they are taken out to cure infection, these patients need to be monitored closely for cardiac issues.”

The second biggest factor contributing to high cost was IV antibiotics. “We think that if the management decisions are made quickly, including expedited removal of infected hardware and placement of a new device, these patients could be moved from critical care to a regular floor sooner, leading to shorter length of hospital stay and major cost saving,” says Sohail.

It’s also worth discussing the socioeconomic cost of infection, adds Margey. “The cost of the device being put in the first time may be around $8,000 to $12,000 for a pacemaker or up to $25,000 for an ICD [implantable cardioverter defibrillator]. If you take that out and throw it away, that’s obviously lost money. Then you have the cost of putting in a brand new device. It winds up being a significant number.”

Recovery and Mortality
Infection greatly impacts a patient’s recovery. While a patient’s age doesn’t increase the likelihood of infection, the older and more debilitated the patient is, the longer it could take to recover from infection. “This is a sick population we’re talking about so the development of an infection is a serious complication that needs to be handled aggressively,” says Margey, who advocates prompt and total removal of a device once infection is discovered. “Obviously we’re talking about patients that have medical conditions which required these devices in the first place, so that’s also of concern.”

There are essentially two types of infection that may occur following surgery for an implantable device. The first is a local infection at the operative site. “This type of infection usually presents early on and is called a pocket infection,” says Greenspon.

The second, more serious type of infection in patients with cardiac devices is a systemic infection that occurs in the bloodstream and is also known as lead-associated endocarditis. In his research, Greenspon found that some patients developed this type of infection long after surgery.

“In these patients, the mean time to the development of systemic infection was two years, so in these cases systemic infection had nothing to do with the primary device implantation,” he explains. “That’s a scary truth because the cardiac device in a patient that develops a bloodstream infection can also become infected. In our research, we found that these bloodstream infections came from various remote sources. For example, a woman received an epidural injection and then developed a bloodstream infection. Her pacemaker lead then became infected. So once an infection gets into the bloodstream, the cardiac lead associated with the pacemaker or implantable defibrillator can also become infected, and that’s a serious complication.”

One concern with these types of infections, says Greenspon, is that they aren’t always easily diagnosed. If a patient comes in with a bloodstream infection, it may present as atypical pneumonia or something else, and the fact that such a patient’s pacemaker or defibrillator is infected might not be a first thought. “The bottom line is that the physician for any patient who develops a systemic infection and has an implanted device always needs to consider the fact that the leads may be infected,” says Greenspon. “The leads are in the bloodstream so they can pick up that infection. It seems obvious but I’m not sure it’s something that’s always considered since these types of infections can present in funny ways and lead physicians off track. But the answer to lowering the mortality rate from these types of infections is early identification.”

It was also determined, according to Sohail’s paper, that about one-half of the increased long-term mortality occurred after patients were discharged from the hospital. “This is a striking finding, especially considering that the majority of these patients were not sent directly home but to some other facility or nursing home,” says Sohail. “That puts some burden on the nurses or physicians taking care of these patients after they are discharged. They need to be aware of the risks of infection and prepared to refer their patient back to the cardiologist if there are any signs of it.”

“Physicians following up with the patient need to be looking for any early signs of infection, including puss or discharge, redness, or pain,” adds Margey. “If the patient has any of those signs, they need to be referred back to the electrophysiologist or cardiologist that did their surgery.”

Once a patient is back in the care of his or her surgeon, Margey advocates for swift care. The more time that elapses, the greater the risk of serious complications from the infection. “The cardiologist or electrophysiologist should take skin swabs from the site and have a blood culture drawn,” says Margey. “Once the device is removed, the physician needs to do a pocket swab and send the leads for culture. All of those steps will help determine the type of organism causing the infection and thus the type of antibiotic that will be used to treat it. In a pocket or systemic infection, the patient will likely need IV antibiotics for up to eight weeks.”

Following removal of an infected device, the risk of the infection recurring is greater, so it’s important that patients are monitored closely, says Sohail. “Watch for the fever, redness, or drainage from the pocket site or a drop in blood pressure,” he advises. “Even a general feeling of being unwell might be a warning sign that something isn’t right. If any signs suggest the infection is coming back, the physician should look at the generator pocket and make sure there is no swelling or redness. It’s also always important that any physicians involved in the patient’s post-op care keep in close collaboration with the electrophysiologist or cardiologist that put the device in.”

Infection Prevention
Obviously the best solution for these complications would be to prevent an infection in the first place. According to Greenspon, every time a patient has a repeat operation, the risk of infection is significantly increased. “Whether it’s getting a battery changed or a new lead, each time there’s an operation, the risk is magnified,” he says. “That says a lot about getting it right the first time.”

Sohail says perhaps the most important factor in preventing infection in the first place is proper implantation technique. “Adherence to standardized aseptic techniques and making sure everything is sterile is really important,” he says. “These may sound self-evident and pretty standard—and they are—but washing hands, wearing gloves and gowns, and maintaining a sterile field at all times needs to be emphasized in the operating room. Studies have shown that a team approach to creating a sterile environment, including having someone monitoring the adherence to these standards, can have a great impact.”

Giving the right antibiotics at the right time is another key element in infection prevention, says Sohail. Until 2009, there was a lot of debate as to whether antibiotics were really vital in preventing infection, but a study published in Circulation: Arrhythmia and Electrophysiology around that time demonstrated a huge difference among patients who received preventive antibiotics vs. those who did not.

“Based on these data, all patients should get antibiotics before device implantation,” says Sohail. “While most physicians already acknowledge this, the challenge in the real world is to make sure that antibiotics are given at the correct time—within 60 minutes of the incision being done to put the device in. Also, if the procedure lasts more than four hours, the patient should receive another dose. Not getting the timing correct or perhaps not getting that second dose may lead to an increase in the likelihood of infection. While most of the device community understands that antibiotics are a standard part of care for these patients, it doesn’t mean mistakes surrounding antibiotics aren’t made. So proper administration needs to be more closely considered.”

Margey adds that to protect infection the pocket site, where the battery is implanted, should also be irrigated with topical antibiotic solution to wash out any bacteria in the pocket before closing the skin with sutures. There’s also some evidence, says Margey, that the experience of the physician doing the surgery may impact the risk of infection. “If the patient sees a physician who does several hundred device implantations in a year, their risk of infection is likely lower than a physician who only does a small number of surgeries,” he says. “That’s because an inexperienced surgeon is going to take longer to do the surgery, and the longer the surgery takes, the more chance there is for bacteria to breed.”

While the possibility of infection is a serious issue, in most cases, the lifesaving benefits of these devices clearly outweigh the risk. Still, it’s worth weighing the options, particularly in older patients. “Thought needs to be given when it comes to elderly patients that are extremely frail or sick about what benefit that patient will get from the device,” says Greenspon. “It’s a conversation that every physician needs to have with their patient beforehand. In the 90-plus-year-old frail patient, it may be that the risks associated with the surgery aren’t worth the benefit. But that’s a scenario to determine on a case-by-case basis.”

— Lindsey Getz is a freelance writer based in Royersford, Pennsylvania.