New mesh pocket for heart devices reduces infection, says study

7th July 2015

A simple mesh pouch containing substances that fight bacteria may significantly reduce major infections caused by heart devices, new research suggests.

Over 1,100 people, who had the pouch fitted with replacement pacemakers and internal defibrillators (ICDs), had an 80 per cent cut in infections at the device site one year later.  The figures were compared to a 2006 study of people who had their devices replaced without the pouch.

This observational study was presented to a European Heart Rhythm Association meeting by the research’s lead author Dr Charles Henrikson from the Oregon Health and Science University, Portland.

Dr Henrikson said the 2006 research showed that after having an ICD or biventricular pacemaker replaced, just over two per cent of 451 patients got an infection.

Heart device pocket

The new TYRX Antibacterial Envelope, produced by Medtronic, was designed to fight against this by holding the device in place while releasing the anti-infection agents minocycline and rifampin over a week.

A total of 670 people having a replacement  biventricular  pacemaker and 459 getting an updated ICD took part in the study at one of 55 sites in America. The figures were then compared them with those who took part in the earlier study.

Only one of the patients getting the biventricular pacemaker with the special pocket had a major infection (0.2%) in the following year - a 90% relative infection reduction. There were four major infections for those receiving an ICD with the pocket (0.6%), a 73% relative infection reduction. Combined, there was a 0.4% infection rate and an 80% relative reduction.

There were also 50 other complications (4.4%), which Dr Henrikson said were mostly driven by bruising. However, there were no real differences in  these between the respective groups.

Researchers are now recruiting 7,000 people for a world wide trial that will examine the benefits from an absorbable form of pocket that is made with dissolvable stitches. The non-absorbable version, which was used in the current study, was made of the polymer resin polypropylene.

Both types of envelopes have been cleared by the US Food and Drug Administration and are currently available in America and Europe.