Letter to the Editor

DOI: 10.19102/icrm.2013.040302

A Case of Gold-coated Pacemaker for Pacemaker Allergy

Editor-in-Chief

In the September 2012 issue of the Journal of Innovations in Cardiac Rhythm Management (Volume 3, Number 9), I read a published case by Goli et al, entitled “A Case of Gold-coated Pacemaker for Pacemaker Allergy.” This manuscript purports to describe a case of an allergic reaction to titanium, resulting in erosion of an implanted pacemaker to the skin surface. No concrete evidence of allergy was provided to support the authors' clinical impression that the findings were due to an allergic reaction. There is no report of tissue being sent to pathology to look for cellular evidence of an allergic response, and a subsequent skin test to look for a titanium allergy was negative. The authors apparently dismiss infection as a primary cause for pacemaker erosion, despite reporting “incisional erythema” and a “non-healing incision” following pacemaker implantation. Presumably, the “negative” wound and blood cultures led the authors to this conclusion. Figure 1 shows an exposed, eroded pacemaker, which by definition is infected, regardless of wound culture results.

There are rare circumstances where a patient may have an unusual allergy that complicates a device implant (e.g., “Allergic reaction to suture material after an ICD procedure: device infection mimicry,” Tschabrunn et al, J Cardiovasc Electrophysiol 2012; 23:330–332). But, given the data in this case, and the approximate 0.5–1.0% risk of infection at the time of pacemaker implantation, it is vastly more likely that the first pacemaker simply got infected at the time of implantation, and gradually worked its way to the surface. The most common organism to infect device pockets is Staphylococcus epidermidis, which is a relatively indolent organism that can create device infections/erosions with minimal erythema or purulence, and can sometimes even take months or years to become clinically apparent. The description of the wound appearance after pacemaker implantation, the time frame for pacemaker erosion, and the appearance of the wound in Figure 1 are all classic for a S. epidermidis pocket infection that started at the time of pacemaker implantation. Wound cultures do not have 100 sensitivity or specificity to diagnose a pocket infection, as bacterial growth may simply reflect local skin flora (which may or may not also be the pocket pathogen), and sometimes bacteria do not grow at all. But whenever foreign material is exposed, it is absolutely infected with at least the same bacterial flora that coats the skin surface.

In this case, I do not believe a gold-coated pacemaker was necessary upon repeat implantation, but instead, I would expect that sterile technique and a new implantation site would have yielded a good outcome with a standard titanium-encased pacemaker. Of note, it is standard practice to implant the new device at the contralateral pectoral site after device explantation/extraction for a pocket infection in order to minimize the risk for infection recurrence. Pacemakers can be implanted via a persistent left superior vena cava, and this would probably have been the best reimplantation strategy in this case.

I therefore believe that the premise of this case report is based on faulty logic, and that a much more common mechanism of pacemaker erosion was likely at play – that of primary pocket infection. It is of critical importance that the Journal of Innovations in Cardiac Rhythm Management readership appreciates that an exposed cardiac device is absolutely infected and that a negative wound culture does not mean the absence of infection. The concluding statement for this report should therefore not have been “A negative reaction to patch testing does not rule out an allergy to pacemaker components,” but instead should have read “Negative wound and blood cultures do not rule out a device infection; any exposed device is definitely infected, and the proper management is complete device and lead extraction, with subsequent contralateral reimplantation whenever possible.”

Joshua M. Cooper, MD
E-mail: Joshua.Cooper@uphs.upenn.edu
Associate Professor of Medicine
University of Pennsylvania Health System
Philadelphia, PA