Absorbable Envelope Cuts Infections After Cardiac Device Implantations

Cardiac implantable electronic devices (CIED) provide many benefits to the 1.7 million people worldwide who receive them each year. Pacemakers and cardioverter defibrillators save lives by keeping the heart from falling into an abnormal rhythm. Infections as a result of the implantation of these devices is rare; however, when they occur they can be difficult to treat and result in endocarditis, a potentially fatal infection of the inner lining of the heart chambers and valves.

An article in The New England Journal of Medicine reports that a team of investigators, led by Khaldoun G. Tarakji, MD, MPH, from Cleveland Clinic, ran a randomized, controlled trial to evaluate an absorbable, single-use, mesh antibiotic-eluting envelope in terms of how well it prevented infection in patients who received a CIED. The envelopes release minocycline and rifampin into the tissues surrounding the heart for at least a week, becoming fully absorbed by the body roughly 9 weeks post-surgery.

From January 2015 to July 2017, the investigators enrolled more than 7000 patients, ultimately assigning 6983 patients at 181 medical centers around the globe to 1 of 2 groups — those that had their CIED implanted inside an antibiotic-eluting envelope and those who did not. The participants were assigned to the groups in a 1:1 ratio, and participants in both groups were determined to have a similar risk of infection based on their average age, previous infection history, and comorbid conditions. All received standard preventive antibiotics before their surgeries.

After 12 months, 42 patients in the control group—the group that had not received the envelopes–had developed infections compared with 25 patients in the group that did receive the envelopes. Complications had developed in 236 patients in the control group compared with 201 patients in the group receiving the envelopes.

“In a population of patients who were at increased risk for CIED pocket infection, the envelope was significantly more effective at preventing infection than standard infection-control strategies alone,” wrote the authors. “The efficacy objective was met, with 40% fewer patients in the envelope group than in the control group having a major infection through 12 months of follow-up.” The authors noted that the envelope’s infection-prevention benefits were particularly noticeable in patients who received high-powered implantable devices such as cardioverter defibrillators versus those who received low-power devices such as pacemakers.

The study also aimed to determine the safety of the implantable envelope, and here too it was found acceptable, with fewer complications occurring in the patients who received it. “This finding helps to allay concerns that the larger incision and tissue dissection required to accommodate the envelope may result in hematoma formation or other complications,” Federico Perez, MD, and Robert A. Bonomo, MD, infectious disease specialists at the Cleveland Clinic who were not involved in the study, wrote in an accompanying editorial in The New England Journal of Medicine.

The authors noted that the implantable envelope was available to patients outside of the trial at the time they were enrolling subjects, which could have affected participation. Also, the control group had a higher percentage of subjects using immunosuppressive drugs; however, as just 1 major infection occurred in these patients in the first 12 months, this factor probably was not a major influence on the results.