Microbiology and Pathogenesis of Cardiovascular Implantable Electronic Device Infections

Abstract

A dvancements in our understanding of cardiac conduction abnormalities and pathophysiology of congestive heart failure coupled with innovations in device manufacturing and programming have helped to create a demand for a plethora of newer cardiovascular devices over the past 3 decades. Appropriate use of cardiovascular implantable electronic devices (CIEDs) in carefully selected patients is associated with better survival and significant improvements in quality of life. 1 Cardiac resynchronization therapy devices are the newest "breed" to join an existing and growing family of permanent pacemakers (PPMs) and implantable cardioverterdefibrillators (ICDs). The number of cardiac devices implanted each year continues to grow exponentially. Unfortunately, because of the invasive nature of the implantation procedures required for placement of these devices and multiple comorbid conditions in device recipients, the benefits of these devices can be eclipsed by infectious complications. Infection is a very serious and dreadful complication requiring complete removal of the infected device and systemic antimicrobial therapy. [2][3][4] Moreover, the financial cost of managing device infections is enormous. In this article, we review the latest developments pertaining to CIED infections, with a special emphasis on pathogenesis and microbiology. EpidemiologySince their first conceptualization and use in the late 1950s, 5 CIEDs have undergone significant enhancements in design and function, and their use continues to rise, with a growing number of indications for placement, improvements in implantation techniques, and enhancements in device programming and monitoring. 1 Earlier investigations reported a highly variable CIED infection rate, ranging from 0.13% to 19.9%. 6,7 However, a more recent review of case records from the Massachusetts General Hospital reported 21 (1.2%) ICD-related infections among 1700 patients who underwent device implantation procedures. 8 In a study by Mela et al, 8 CIED infection occurred in 1.8% of 1170 patients who underwent a primary implant, a generator change, or a revision of their systems. In a population-based study from Olmstead County, Minnesota, the estimated rate of CIED infections was 1.9 per 1000 device-years. 9 Interestingly, the cumulative probability of device infection in this study was higher among patients with ICDs than in those with PPMs, 9 an observation that has also been reported by other investigators. 10 Contrary to expectations that increasing sophistication in device manufacturing and implantation techniques, coupled with higher volumes of implantation and more experience, will lead to a reduction in the CIED infection rate, recent data from large database surveys suggest that the rate of infectious complications has been rising out of proportion with the rate of CIED implantations. According to National Hospital Discharge Survey 10 data from 1996 to 2003, 180 284 PPMs and 57 436 ICDs were placed in 2003, representing a 49% increase in the number of implants during the s...

Microbial diagnosis of infection and colonization of cardiac implantable electronic devices by use of sonication

“…[1][2][3] Indeed, data collected in 2009 from 61 different countries have shown a continuous rise in the number of cardiac implantable electronic devices (CIEDs) being inserted worldwide, with the highest number of implanted PPMs in the USA (225 567) and Germany accounting for 927 new implants per million population. 4 Although infection following CIED use remains relatively uncommon, it may affect exclusively the generator pocket, intravascular electrode components, or endocardial structures, or may even present in different combinations, making the clinical suspicion often delayed and not considered.…”

Sonication of Explanted Cardiac Implants Improves Microbial Detection in Cardiac Device Infections

“…Staphylococcal species, including both Staphylococcus aureus and coagulase-negative staphylococci, account for the majority of CDIs (7,9); however, unusual organisms (Propionibacterium spp., Corynebacterium spp., Acinetobacter baumannii, Haemophilus influenzae) are also found, and antibiotic resistance is often detected (10)(11)(12)(13). Moreover, there are data indicating that microorganisms can colonize cardiac devices without clinical signs of active infection (14)(15)(16).…”

An off-the-shelf plasma-based material to prevent pacemaker pocket infection

“…First, only S. aureus was utilized. For the purpose of this experiment, we sought a species that represented the bulk of clinical infections, grew aggressively, and formed biofilms on prosthetic surfaces [36]. It is possible that the efficacy of PBM(þMR) paste demonstrated in the present study would not have been observed using other organisms also encountered in clinical practice.…”