Antibiotic eluting envelopes: evidence, technology, and defining high-risk populations.

Cardiovascular implantable electronic devices (CIED) are effective and important components of modern cardiovascular care. Despite the dramatic improvements in the functionality and reliability of these devices, over time patients are at risk for developing several morbidities, the most feared of which are local and systemic infections. Despite significant financial investment and aggressive therapy with hospitalization, intravenous antibiotics, and transvenous lead extraction, the outcomes include a 1-year mortality rate as high as 25%. This risk of infection has increased over time, likely due to the increased complexity of the surgical interventions required to insert and replace these devices. The only way to reduce this morbidity and mortality is to prevent these infections, and other than preoperative antibiotics, there were little data supporting effective therapy until the WRAP-IT trial provided randomized data showing that pocket infections can be reduced by 60% at 12 months and major CIED infections reduced by 40% at 1 year with the use of the absorbable antibiotic eluting envelope in patient CIED procedures at high risk of infection. Not all CIED procedures are at high risk of infection and justify the use of the envelope, but cost-effectiveness data support the use of the antibiotic envelope particularly in patients with defibrillator replacements, revisions, and upgrades, such as to a resynchronization device and in patients with prior CIED infection, history of immunocompromise, two or more prior procedures, or a history of renal dysfunction.