CENTURION, CITADEL: Novel Antibacterial 'Pouch' Decreases Infections After Cardiac Device Replacements

Deborah Brauser

June 22, 2015

MILAN, ITALY — A simple mesh "pouch" containing antimicrobial agents may significantly reduce major infections caused by cardiac implantable electronic devices (CIEDs), new research suggests[1].

After combining results from the CITADEL and CENTURIAN registry studies, the investigators found that the group of 1129 high-risk patients undergoing a CIED replacement that used the TYRX Antibacterial Envelope (Medtronic) had 80% reductions in surgical-site infections 1 year later (which was the primary end point) vs "historical data" of CIED replacement patients who did not receive the pouches.

"While these are observational data, they do show a substantially lower infection rate without any real increase of mechanical complication rate," lead author Dr Charles Henrikson (Oregon Health and Science University, Portland) told heartwire from Medscape. He presented the findings at a moderated poster session at the European Heart Rhythm Association (EHRA) EUROPACE-CARDIOSTIM 2015 meeting.

In-the-Pocket Protection

Dr Charles Henrikson

Henrikson noted that research from 2006 showed a 2.2% patient infection rate after implantable cardioverter-defibrillator (ICD) or cardiac resynchronization therapy (CRT) device replacements in 451 patients[2].The TYRX was designed to fight against this by holding a cardiac device in place while releasing minocycline and rifampin over 1 week.

The CENTURION study was created to assess whether the TYRX could significantly reduce infection after patients underwent a replacement CRT generator (n=670), whereas CITADEL was created to assess the same thing in patients receiving a replacement ICD (n=459). All patients were enrolled at one of 55 sites in the US; the investigators then compared them with those who participated in the Gould study[2] to act as a control or "comparator" group.

In the CITADEL analysis, only one of the patients receiving a CRT placed within the antibacterial pocket had a major infection (0.2%) within the following year. "This meant there was a 90% relative infection reduction to the comparator [P=0.005]," said Henrikson. There were four major infections for those receiving an ICD within the pocket (0.6%), for a 73% relative infection reduction (P=0.018). Combined, there was a 0.4% infection rate and an 80% relative reduction (P=0.002).

There were also 50 CIED mechanical complications (4.4%), which Henrikson said were mostly driven by hematomas. However, there were no differences in hematoma rates between the CITADEL-CENTURION combo group and the comparator group after 12 months (both 1.6%).

Henrikson reported that the investigators are now enrolling for the World-wide Randomized Antibiotic Envelope Infection Prevention Trial (WRAP-IT), with a goal of 7000 patients included. However, that trial will examine the benefits from an absorbable form of the pocket that is made with dissolvable suture. The nonabsorbable version, which was used in the current study, was made of a "polypropylene mesh scaffold."

Both types of envelopes have been cleared by the US Food and Drug Administration and are currently available in the US and in Europe. A representative for Medtronic told heartwire that although the nonabsorbable version cost roughly $600 to $800, the absorbable version will cost around $1000.

"But treating infections is also quite expensive," said Henrikson.

Good Option But Pricey

Absorbable version of the Tyrx envelope with an ICD

Dr Tayfun Acil (New Century University, Istanbul, Turkey) noted that he appreciated seeing a way "to keep all the parts together" during implantation. Also, "there is a big problem with infection in some of these patients, but this medicated mesh seems to give an advantage," said Acil, who was not involved with the research.

"I think it's a good idea. And not just in high-risk groups, because you never know in which patient an infection might happen. So this is a nice option," he said, adding that he'd consider it in his own practice.

Session moderator Dr Iraklis Mavrakis (Heraklion, Greece) said that in his 15 years of clinical experience with cardiac devices, he's observed a strong need for lowering infection rates—especially in replacements. "We've seen that infection increases as the number of replacement increases. The 2.2% rate [in the Gould study] is for a first replacement. But if you replace two, three, or four times, that rate just grows," he said.

"For the pouch, I think the price is affordable at around $700 if it really reduces infection. If it does that, it could be very promising. But we need to see the results of the randomized study."

However, when Mavrakis was informed of the higher price for the absorbable version, he was more skeptical. "I think we'd have to improve that price. The envelope should be affordable," he stressed to heartwire .

The study was funded by TYRX. Henrikson reported having received fellowship support from Medtronic, Boston Scientific, and St Jude Medical and has received research grants from Biosense Webster. Acil and Mavrakis reported no relevant financial relationships.


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