An absorbable, antibiotic-eluting envelope around cardiac implantable electronic devices could significantly reduce the incidence of infection, according to a presentation at the annual meeting of the American College of Cardiology.
The WRAP-IT trial, which was simultaneously published online March 17 in the New England Journal of Medicine, involved 6,983 patients undergoing cardiac implantable electronic device (CIED) implantation, replacement, revision, or upgrade. Patients were randomized either to receive the TYRX Absorbable Antibacterial Envelope or not.
After a mean follow-up of 20.7 months, there was a significant 40% lower rate of major infections in the envelope group compared to the control group, which met the efficacy objective of the study. Researchers saw 30 major infections in 25 patients in the envelope group; in the control group, there were 45 major infections in 42 patients (P = 0.04). The trial excluded patients at high risk of systemic infection due to other sources and patients with existing infection.
“CIED infection is a rare but serious event, and its management requires prolonged hospitalization, which involves device and lead extraction with adjunctive antibiotic therapy,” wrote Dr. Khaldoun G. Tarakji, from The Cleveland Clinic, and co-authors. “Despite proper management of CIED infection, both short- and long-term mortality remains high.”
One previous randomized study had shown that intravenous administration of antibiotics during CIED procedures can reduce the risk of infection, while a different study failed to find a benefit. The vast majority of patients in this study (98.7%) received periprocedural antibiotics, 74.5% received pocket wash and 29.6% received post-procedural antibiotics. These strategies were not controlled, but there is no clear evidence that any particular strategy influenced the infection rate, the authors wrote.
Patients in the envelope group experienced numerically fewer pocket infections but more endocarditis or bacteremia compared to those in the control group, a finding that the authors could not explain.
The most common pathogen responsible was staphylococcus, but data on antibiotic susceptibility was not collected. The authors stressed that this limited their ability to assess the risk of antibiotic resistance developing.
In this study, the researchers noted that the reduction in the risk of infection was greater among individuals who were implanted with higher-power devices, compared to those implanted with low-power devices or an initial cardiac resynchronization therapy device.
However, they said, the rate of infections was generally lower among those receiving low-power devices.
There was no increase in complications related to use of the envelope. The rate of complications occurring within 12 months of the procedure and relating to the CIED procedure or envelope was 6% in the envelope group and 6.9% in the control group.
When major infections were excluded, the rate of complications in each group was 5.7% and 5/9% respectively. There was also no significant difference in mortality rates between the two groups (17.4% and 17.8% respectively).
The authors wrote that while use of the envelope can require a slightly larger CIED dissection pocket, this was not associated with increased procedural time or complications. The envelope was successfully implanted in 99.7% of procedure attempts.
“There were fewer system revisions in the envelope group than in the control group and no complications due to allergy to the envelope mesh, polymer, or antibiotics,” they wrote.
The study was supported by Medtronic, the maker of the TYRX Absorbable Antibacterial Envelope. Twenty-four authors declared institutional funding or research grants from Medtronic, thirteen declared fees, consultancies and other support from private industry outside the submitted work. Three authors were employees of Medtronic.
SOURCE: Tarakji K et al. NEJM, 2019, March 17. DOI: 10.1056/NEJMoa1901111