Medtronic Tyrx antibacterial envelope reduces cardiac device infection rates at 12 months


Medtronic has announced that its Tyrx antibacterial envelope reduces major cardiac device site infections by 80%, up to 12 months after implantation. These data were presented at Heart Rhythm 2015, the Heart Rhythm Society’s 36th Annual Scientific Sessions (13–16 May, Boston, USA).

The Citadel/Centurion Clinical trials are the first prospective, multicentre studies to evaluate the impact of the Tyrx antibacterial envelope on cardiac implantable electronic device (CIED) major infections and mechanical complication rates following implantation in high-risk patients. The results show a low rate of surgical site infection at 12 months (0.44%) in the 1,129 patients who received the Tyrx compared with a control group of similar patients reported in previously published literature who did not receive an envelope (2.2%; p=0.0023).

CIED infections are associated with substantial morbidity, mortality and cost and are increasing in frequency. The average cost of a CIED infection in the USA is estimated at US$54,926.

“Clinical studies show that the use of the Tyrx envelope is associated with a significant reduction in implant-related cardiac device site infections,” said Charles A Henrikson, chief of electrophysiology at Oregon Health & Science University in Portland, USA. “These new findings reveal that the Tyrx decreases the rate of infections that can occur within the first year after implantation. This is very good news for patients, especially given the associated mortality and costs tied to CIED infection.”

Twelve-month results of Citadel/Centurion clinical trials

The Citadel/Centurion Clinical trials enrolled 1,129 patients at 55 centres in the USA. Study participants were at high risk for infection because they were undergoing a CIED replacement procedure with either an implantable cardioverter-defibrillator (ICD) (Citadel) or a cardiac resynchronisation therapy (CRT) device (Centurion). Primary endpoints were major CIED infection (involving any site other than skin or subcutaneous tissue of the incision, or endocarditis) and CIED mechanical complication over 12 months of follow-up. The frequency of CIED mechanical complications in patients implanted with the Tyrx envelope was low.

“These data support the long-term safety and efficacy of the Tyrx and showcase the clinical benefit of this novel technology for cardiac device patients at increased risk for infection,” said Marshall Stanton, vice president and general manager of the Tachycardia business, which is part of the Cardiac and Vascular Group at Medtronic.

Results of independent study of TYRX absorbable antibacterial envelope

Also at Heart Rhythm 2015, researchers at Vanderbilt University Medical Center, USA, independently reported that the Tyrx was associated with a low incidence of CIED-related infection in a high-risk population, comparable to that seen with the original non-absorbable Tyrx antibacterial envelope.

“Our study is the first-of-its-kind, comparing the incidence of major cardiac device-related infection in high-risk patients who, during implantation, received either the Tyrx absorbable envelope or the non-absorbable envelope, with a control group of patients who did not receive a Tyrx,” said Christopher R Ellis, principal investigator of the study and assistant professor of medicine at Vanderbilt University Medical Center. “After a minimum of three months, results showed only one reported infection in the 488 patients who received either the original or newer, absorbable Tyrx envelope, compared with 20 infections in the control group of 638 patients. Additionally, it was encouraging to find no difference in infection rates between the original envelope and the newer, fully absorbable version.”