New Orleans, LA - Preimplantation fever, the use of a temporary pacing wire before implantation, and early reintervention are all risk factors for infectious complications following the implantation of antiarrhythmic device systems, according to the results of a large French study.[1] The investigators recommend a treatment course with antibiotics before and after implantation, as antibiotic prophylaxis was inversely correlated with infectious complications in this analysis.

"It is possible to prevent or reduce infection that arises after device implantation," Dr Didier Klug (Lille University, France) told heartwire. "We know that there are several risk factors that can lead to infections. Here, we had more than 6000 device implantations and were able to show that to prevent complications, we have to avoid, if possible, the use of a temporary pacing wire and to reschedule procedures if the patient has a fever. If we can avoid early reintervention, that would also help the patient as well."

The results of the study, a multicenter trial known as the Prospective Evaluation of Pacemaker Leads Related to Endocarditis (PEOPLE), were presented this week at the Heart Rhythm Society 2005 Scientific Sessions.

Between January 1 and December 31, 2000, a total of 6319 consecutive recipients of implantable antiarrhythmic devices were enrolled at 47 medical centers and followed for 12 months. All infectious complications were recorded. The aim of the study was to determine whether the occurrence of infection was related to different factors, including operator experience, implantation conditions and duration, type of system implanted, patient characteristics, and other procedure-related factors.

Overall, there were 5866 pacing systems implanted, including 3789 dual-lead and 117 multisite systems. The remaining 453 device implantations were ICDs, including 178 with dual-lead systems. More than 4400 of the device implants were de novo implantations. Reinterventions were performed before discharge from the hospital in 91 patients.

At 12 months, confirmed pacing-system- or ICD-related infections were reported in 42 patients (0.68%). Multivariate analysis revealed that confirmed infection was correlated with fever, the use of a temporary pacing wire before implantation, and early reintervention. On the other hand, infection was inversely correlated with de novo implantation and antibiotic prophylaxis.

Multivariate analysis of variables of infection

Variable	Odds ratio
Fever (temperature >37°C)	5.8
Temporary pacing	2.4
Reintervention	11.2
Pulse generator or lead replacement	2.4
No antibiotic prophylaxis	4.2

Commenting on the issue of infection to heartwire, Dr Dwight Reynolds (University of Oklahoma Health Sciences Center, Oklahoma City) said that while the frequency of infection is low, typically occurring in 1% to 2% of device implantations, it remains a serious problem.

The study also reiterates the value of antibiotic therapy, said Reynolds, noting that the treatment administered varies among centers. Clinical-trial data have shown the value of antibiotics one hour before the procedure, but an additional dose of therapy is typically given after the implant. Reynolds added that many EPs also irrigate the ICD "pocket" before implantation with a polyantibiotic solution known as "holy water."

"We don't have any data to prove that it does any good, but we do it anyway," said Reynolds. "That's because even though the frequency of infection is very low, the severity of infection is major. It has very big economic implications, especially because you can't simply sterilize the device and put it back in."

One of the problems with device-related infection is that it often forces the removal of pacemaker and ICD leads also. According to Reynolds, there is a clear connection between a pocket infection and infections that creep into the blood vessels. Removing the implanted leads is a complex, expensive procedure that requires cardiologists and anesthesiologists, as well as surgeons ready to step in if there is a tear in the wall of the vessel or heart.

"What we've learned over time is that we can't eradicate even pocket infection with a simple removal of the device," said Reynolds. "What we tend to need to do is take the wires out when we remove the ICD or pacemaker. The cure rate for these things is only about one in four unless you take out everything."

Extracting infected leads in patients with vegetations

In a separate study, investigators from Drexel University showed that the removal of infected leads in patients with intracardiac vegetations can be safely performed using standard device explantation techniques.[2]

Dr Christopher Schulze

"Percutaneous extraction of infected leads in patients with vegetations, regardless of the size of the vegetation, is a safe procedure," lead investigator Dr Christopher Schulze (Drexel University College of Medicine, Philadelphia, PA) told heartwire. "We can take these systems out without the patients needing to undergo thoracotomy bypass surgery. What we can say is that the size of the vegetation should not be a limiting factor when deciding whether a patient should get percutaneous extraction."

The data are based on the experience of a single center documenting percutaneous lead extractions performed between 1991 and 2005. During this time, a total of 714 patients underwent extraction of 1278 leads. Systemic infection was present in 315 of these patients. Overall, 62 patients had documented intracardiac vegetations, resulting in the removal of 128 leads in these patients. The mean extraction time per lead for patients with vegetations was 17 minutes. Five patients died after extraction from sepsis at least five days after extraction. Thirty-day all-cause mortality was 6.5%.

"Patients who come for extraction for either device malfunction or infection are often higher risk," said Schulze. "A subset of the patients who come for extraction because of an infection will have a growth of infected material along the course of the lead. There is a fear among a lot of people that extracting the leads without surgery would lead to this piece of vegetation embolizing to the lungs. But we have not found any complications related to extraction. We are able to get the lead and device out of the body without any problems related to the extraction procedure."

Once signs of clinical infection were absent and serial blood cultures were clear, the device was reimplanted in 39 patients after a median of eight days (range 3-60 days). Patients receive long-term antibiotic therapy for four to six weeks following reimplantation, noted Schulze.