Infections related to a first cardiac implantable electronic device (CIED) tend to emerge sooner and more aggressively than those associated with replacement CIEDs or pocket revisions, a prospective registry study suggests.
Patients with infections associated with de novo CIEDs, compared with reoperation-related infections, also “tended to have more sepsis, more valvular regurgitation, and be a sicker group” as gauged by the Charlson Comorbidity Index, observed Jordan M Prutkin, MD, University of Washington, Seattle, for theheart.org | Medscape Cardiology.
Infections related to first-time devices also showed a dominance of Staphylococcus aureus rather than the coagulase-negative staphylococcal bacteria most common in the reoperation-related infections.
The latter organisms, Prutkin said, often make for “more indolent, slow-growing infections, compared to Staph aureus, which usually presents more fulminant.” All that is consistent with the earlier and more aggressive infection in the patients with de novo CIEDs, he noted.
On the other hand, mortality didn’t differ significantly between the two groups, either in-hospital or at 6 months, in the analysis based on the Multicenter Electrophysiologic Device Infection Cohort (MEDIC) prospective registry of patients with CIED infections at 11 international sites, mostly in the United States. It was published March 30 in OpenHeart, with Mariko W Harper, MD, University of Washington, Seattle, as lead author and Prutkin as senior author.
In most cases of CIED-related infection, “we’re going to recommend removal of the device,” Prutkin said, consistent with widely common practice.
Still, he said, current findings are consistent with the possibility, though they do not directly show it, that “you have to be more aggressive about trying to remove the device earlier” with de novo CIED infections compared with those related to reoperations.
But in some cases of device removal due to the more indolent reoperation-related infections, Prutkin and colleagues propose in their report, there may be an allowable window of time prior to the procedure that can be used to optimize the patient’s medical status.
Still, one of the main messages of the current analysis, he said, is that patients with CIEDs are at risk for device-related infection at almost any time.
“While we showed that people with an initial implant do present earlier, it can be years and years later that someone can develop a device infection, so you really need to stay vigilant with an initial implant or a reoperation, to never tell a patient they’re out of the time window where they might be at risk for infection.”
The cohort included 178 adult patients with infections related to first-time CIEDs and 254 with infections after CIED reoperation. Infection was not suspected at the time of reoperation, which could include access of the pocket for pulse-generator change, addition of leads, revision of pocket or leads, or lead extraction.
In addition to having more comorbidities, the de novo CIED-infection group was significantly more likely to have received immunosuppressive agents in the past 6 months, to have had organ transplantation, and to be on hemodialysis.
Table. Patient and Infection Characteristics and Outcomes Associated With Infections Related to First-Time CIEDs vs Reoperation for CIEDs
| Parameter | First-Time CIEDs (n = 178) | Reoperation (n = 254) | P Value |
|---|---|---|---|
| Male (%) | 76.4 | 79.5 | .48 |
| Median Charlson Comorbidity Index score | 3 | 2 | <.001 |
| Median implant duration (mo) | 21.1 | 71 | <.001 |
| Median time since last procedure (mo) | 8.9 | 19.5 | <.0001 |
| Mean no. of leads | 2.0 | 2.5 | <.001 |
| Solid organ transplant (%) | 2.8 | 0 | .01 |
| Immunosuppressive medications (%) | 10.1 | 4.3 | .03 |
| Localized pocket infection (%) | 48.9 | 70.1 | <.001 |
| Sepsis at presentation (%) | 30.9 | 19.3 | .006 |
| In-hospital mortality (%) | 7.9 | 5.2 | .31 |
| 6-month mortality (%) | 21.9 | 14.0 | .06 |
The analysis suggests that “when you’re on immunosuppressants, when you are on hemodialysis, your risk of an infection related to a cardiac device is significantly higher than in the general population who does not have these risk factors,” Dhanunjaya R Lakkireddy, MD, from the University of Kansas, Kansas City, told theheart.org | Medscape Cardiology.
Perhaps “these are the cases where we need to be thinking about more extended antibiotic therapy after implant,” said Lakkireddy, who isn’t connected to the study. “These are maybe the patients that need to go on 7 to 10 days of postimplant antibiotics.” Usually that isn’t done in such cases, “so maybe that’s one thing that we could do differently.”
He said “this study sort of explains itself,” in that the observed differences between the two infection cohorts are consistent with what’s already been seen in studies and in practice.
That is, in people who do well with a CIED and then need a generator change after perhaps 10 or 12 years, opening up the pocket can seed it with coagulase-negative staphylococci, such as the skin-dwelling S epidermidis. “But the infection is low-grade, less serious,” in part because it doesn’t easily spread beyond the fibrous capsule that has long developed around the pulse generator, Lakkireddy noted.
Device extraction is usually part of the preferred management of infections related to de novo CIED implantation or reoperation, but sometimes less aggressive measures may be enough for reoperation infections limited to the pouch, he observed.
“For localized infections, when there are no bugs in the bloodstream, can you get away with a local treatment? It’s very challenging, outside-the-box thinking,” he said.
Some experts “may cringe” at the idea, but it may sometimes be feasible to open the pocket, clean it out, apply antibiotics, then give oral antibiotics for 3 to 4 weeks, Lakkireddy said, “and see if you can get away with it without extracting the whole system, because the device extraction, especially in a chronic device, is laden with a significant risk of complications.”
He proposed that devices like the TYRX Antibacterial Envelope (Medtronic), an antibiotic-impregnated, absorbable mesh envelope for containing and implanting with the pulse generator, designed to lower the risk for pocket infection, may be especially suitable for CIEDs at reoperation.
The device is under evaluation in the prospective World-Wide Randomized Antibiotic Envelope Infection Prevention Trial (WRAP-IT) trial, with a projected enrollment of more than 7700 patients receiving CIED upgrades or replacements.
Prutkin said he favors routine extraction of the CIED, if possible, in either kind of infection because “there are no predictors of who can be successfully salvaged with just antibiotics alone without doing a device removal.” When it is attempted, the rate of success is low “and there is a rate of recurrence that’s significant.”
He pointed to another analysis based on the MEDIC registry, published April 3 in PACE, that failed to find any clinical or laboratory predictors of successful CIED salvage with local and systemic antibiotics.
The analysis strongly supports “recommendations that optimal management of definite CIED infection includes complete device removal in conjunction with directed antimicrobial therapy,” write the authors, led by James E. Peacock Jr, MD, Wake Forest School of Medicine, Winston-Salem, North Carolina.
Prutkin, Harper, and their coauthors reported no conflicts. Lakkireddy has disclosed speaking for Janssen, Pfizer, and Biotronik and receiving unrestricted research grants from Bristol-Myers Squibb and Biosense Webster. Peacock owns common stock in Pfizer; disclosures for his coauthors are in the report.
OpenHeart. Published online March 30, 2018. Abstract
PACE. Published online April 3, 2018. Abstract
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