Cardiac implantable electronic device infection
ABSTRACT
Increasing numbers of patients with cardiac disease have improved quality of life and longevity as a result of cardiac implantable electronic devices (CIEDs). CIED infections can involve the generator pocket, bloodstream, or cardiac structures and occur in about 0.5% of de novo CIED implants and approximately 2% of CIED replacements. Prompt diagnosis of CIED infection is beneficial to the success of antibiotic therapy and subsequent device removal to resolve the infection. Measures to prevent CIED infections include assessment of the indication and patient status, strict sterile surgical techniques, preoperative antibiotics, and adequate homeostasis. New surgical methods and CIED devices may also lead to reduction in CIED infections. Further research is needed to better quantify the incidence of CIED, risk factors, and efficacy of surgical techniques to prevent infections.
KEY POINTS
- CIED use is increasing, as are the number of CIED infections, which are associated with significant morbidity and mortality.
- Prompt diagnosis of CIED infection allows for early management with antibiotics and device removal, which is typically needed for resolution of the infection.
- Prevention of CIED infection is an important strategy, and more research is needed to inform the incidence of CIED infection, risk factors, and devices and techniques to minimize the risk of infection.
REIMPLANTATION
The need for reimplantation after removal of an infected CIED should be thought about before the extraction. In general, extracting an infected CIED should be viewed as an opportunity to reassess the need for the device. Almost one-third of patients who undergo extraction of infected CIED do not require immediate reimplantation.2 This could be due to reversal of the initial indication, emergence of new clinical conditions, patient preference, or the lack of an absolute indication. If reimplantation is necessary, the new device is typically placed on the opposite side of the chest from the previously infected pocket site after blood cultures are negative for at least 72 hours.21
CIED INFECTION MORTALITY
Despite proper management with CIED removal supported by antibiotic therapy, CIED infection carries a high risk of death. The 30-day mortality is estimated to be between 5% and 6%.33 In a large case series of 412 CIED extractions, there were 19 in-hospital deaths. Of these 19 deaths, 2 were related to the extraction itself with the other 17 related to sepsis, multiorgan failure, stroke, renal failure, or heart failure.2 The 1-year mortality rate is also increased for this population; recent data show 1-year mortality rates of 8% to 17% despite device removal and antibiotic therapy.2,34,35 This increased mortality rate was also demonstrated in a large cohort of Medicare patients undergoing CIED procedures.36 Medicare patients with CIED infection had double the risk of death at 1 year compared with patients without infection.36
Risk factors for death at 1 year include worse baseline functional status, renal failure, and type of infection; eg, endovascular infection carries a risk of death 2 times higher than pocket infection.37
PREVENTION
Because CIED infection carries significant short-term and long-term mortality rates despite optimal management, the best strategy is prevention. Preventing CIED infection begins with the decision to implant a device with careful assessment of the indication, the timing of the procedure, and the patient’s clinical status. CIED procedures are performed under strict sterile surgical techniques with great attention to the incision and proper closure. Surgical data favor the use of chlorhexidine-alcohol solutions for skin preparation compared with povidone-iodine solutions to prevent both superficial and deep surgical wound infections.38 However, recent studies showed no significant difference between the 2 preparation methods in reducing rates of CIED infection.39,40 In individuals colonized with S aureus, the risk of CIED infection can be reduced using a body wash containing chlorhexidine and a nasal spray containing mupirocin.41,42
Preoperative antibiotics
The use of preoperative antibiotics has been shown to reduce the risk of infection.43 In a large prospective cohort of patients undergoing a de novo or secondary CIED procedure, the use of perioperative antibiotics was negatively associated with the risk of CIED infection.13 This was later confirmed by a double-blind randomized trial of 1,000 patients undergoing permanent pacemaker or ICD initial implantation or generator replacement. This study was stopped prematurely as the use of antibiotics was clearly associated with a lower risk of CIED infection.44 Therefore, prophylaxis with an antibiotic active against staphylococci before the incision is made is a class I indication to prevent infection.1
Currently, no data support giving prophylactic antibiotics after the procedure; however, the Prevention of Arrhythmia Device Infection Trial (PADIT) is currently comparing the risk of infection with conventional preoperative antibiotics vs a regimen of pre- and post-procedure antibiotics (clinicaltrial.gov: NCT01628666).
Hemostasis
Adequate hemostasis is critical, since the risk of CIED infection is 7 times greater with formation of a hematoma.45 Heparin products, especially low-molecular-weight heparin, should be avoided at the time of CIED implantation. In patients at high risk for thromboembolism who are on warfarin therapy, the continuation of warfarin is associated with a lower incidence of hematoma compared with bridging with heparin in patients undergoing CIED procedures.46 Therefore, if anticoagulation can be withheld, it is better to stop the anticoagulant before the procedure. When this is not possible or when it carries significant risk (eg, a patient with a mechanical mitral valve who needs a CIED implantation), it is better to maintain the patient on warfarin therapy with a therapeutic international normalized ratio rather than bridging with heparin products.
Antibacterial envelop and new devices
