Impact of Choice of Prophylaxis on the Microbiology of Cardiac Implantable Electronic Device Infections: Insights From the Prevention of Arrhythmia Device Infection Trial (PADIT)

Abstract

Background The Prevention of Arrhythmia Device Infection Trial (PADIT) investigated whether intensification of perioperative prophylaxis could prevent cardiac implantable electronic device (CIED) infections. Compared with a single dose of cefazolin, the peri-operative administration of cefazolin, vancomycin, bacitracin and cephalexin did not significantly decrease the risk of infection. Our objective is to compare the microbiology of infections between study arms in PADIT. Methods Post-hoc analysis. Differences between study arms in the microbiology of infections were assessed at the level of individual patients and at the level of microorganisms using the Fisher’s exact test. Results Overall, 209 microorganisms were reported from 177 patients. The most common microorganisms were coagulase-negative staphylococci (CoNS, 82/209; 39.2%) and S. aureus (75/209; 35.9%). There was a significantly lower proportion of CoNS in the incremental arm compared with the standard arm (30.1% vs. 46.6%, p=0.04). However, there was no significant difference between study arms in the frequency of recovery of other microorganisms. In terms of antimicrobial susceptibility, 26.5% of microorganisms were resistant to cefazolin. CoNS were more likely to be cefazolin-resistant in the incremental arm (52.2% vs. 26.8%, respectively; p=0.05). However, there was no difference between study arms in terms of infections in which the main pathogen was sensitive to cefazolin (77.8% vs. 64.3%; p=0.10) or vancomycin (90.8% vs. 90.2%; p=0.90). Conclusions Intensification of the prophylaxis led to significant changes in the microbiology of infections, despite the absence of a decrease in the overall risk of infections. These findings provide important insight on the physiopathology of CIED infections.

Treatment and Prevention of Cardiovascular Implantable Electronic Device (CIED) Infections

“… 9 Although most CIED infections are believed to result from the device implantation procedure, the recent P revention of A rrhythmia D evice I nfection T rial (PADIT) of intensive antimicrobial prophylaxis showed no significant effect on the overall risk of infection over and above that provided by standard preoperative antimicrobial prophylaxis. 10 One proposed explanation for this finding is that the proportion of CIED infections that have their onset postimplantation may be greater than previously thought. 10 …”

“… 10 One proposed explanation for this finding is that the proportion of CIED infections that have their onset postimplantation may be greater than previously thought. 10 …”

“… 19 Similarly, confirmed CIED infections due to MRSA in the PADIT trial accounted for < 5% of patients in the control arm, with patients enrolled from mainly Canadian and some Dutch centres. 10 …”

Association of the Timing and Extent of Cardiac Implantable Electronic Device Infections With Mortality

“…Early infection was considered present if it occurred 3 months or earlier after the procedure, whereas delayed infection was categorized as occurring between 3 and 12 months after the procedure. The microbiology of pathogens causing CIED infections in PADIT has been previously reported …”

New advances in management and treatment of cardiac implantable electronic devices infections

“…The most common types of microorganisms were S. aureus (35.9%) and CoNS (39.2%) with a low incidence of methicillin-resistant S. aureus (MRSA) in patients enrolled mainly from Canadian and Dutch centers. By contrast, a 2016 large single-center US study that included 816 consecutive patients undergoing device removal for confirmed infection showed that patients with CDIs due to MRSA were about 15% [ 22 ].…”