Cardiovascular implantable electronic device infection: A stepwise approach to diagnosis and management

These days, an increasing number of people are receiving permanent pacemakers, implantable cardioverter-defibrillators, endovascular devices, and cardiac resynchronization therapy devices—collectively called cardiovascular implantable electronic devices (CIEDs). One reason for this upswing is that these devices have been approved for more indications, such as sick sinus syndrome, third-degree heart block, atrial fibrillation, life-threatening ventricular arrhythmias, survival of sudden cardiac death, and advanced congestive heart failure. Another reason is that the population is getting older, and therefore more people need these devices.

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Although the use of a CIED is associated with a lower risk of death and a better quality of life, CIED-related infection can eclipse some of these benefits for their recipients. Historically reported rates of infections range from 0% to 19.9%.¹ However, recent data point to a disturbing trend: infection rates are rising faster than implantation rates.²

Besides causing morbidity and even death, infection is also associated with significant financial cost for patients and third-party payers. The estimated average cost of combined medical and surgical treatment of CIED-related infection ranges from $25,000 for permanent pacemakers to $50,000 for implantable cardioverter-defibrillators.^3,4

Although cardiologists and cardiac surgeons are the ones who implant these devices, most patients receive their routine outpatient care from a primary care physician, who can be a general internist, a family physician, or other specialist. Moreover, many patients with device infection are admitted to hospital internal medicine services for various diagnoses requiring inpatient care. Therefore, an internist, a family physician, or a hospitalist may be the first physician to respond to a suspected or confirmed device infection. Knowledge of the clinical manifestations and the initial steps in evaluation and management is essential for optimal care.

These complex infections pose challenges, which we will illustrate by presenting a case of CIED-related infection and reviewing key elements of diagnosis and management.

AN ILLUSTRATIVE CASE

A 60-year-old man had a permanent pacemaker implanted 3 months ago because of third-degree heart block; he now presents to his primary care physician with increasing pain, swelling, and erythema at the site of his pacemaker pocket. He has a history of type 2 diabetes mellitus, stage 3 chronic kidney disease, and coronary artery disease.

The symptoms started 2 weeks ago and have slowly progressed, prompting him to seek medical care. He is quite anxious and wants to know if he needs to arrange an emergency consultation with his cardiologist.

IMPORTANT CLINICAL QUESTIONS

This presentation raises several important questions:

• What should be the next step in his evaluation?
• Which laboratory tests should be done?
• Should he be admitted to the hospital, or can he be managed as an outpatient?
• Should he be started empirically on antibiotics? If so, which antibiotics? Or is it better to wait?
• When should an infectious disease specialist be consulted?
• Should the device be removed, and if so, all of it or which components?
• How long should antibiotics be given?

We will provide evidence-based answers to these questions in the discussions below.

PATHOGENESIS AND RISK FACTORS FOR DEVICE INFECTION

The first step in understanding the clinical manifestations of CIED-related infections is to grasp their pathogenesis. Risk factors for device infection have been evaluated in several studies.¹

Several factors interact in the inception and evolution of these infections, some related to the care in the perioperative period, some to the device, some to the host, and some to the causative microorganism.⁵ Although any one of these may play a predominant role in a given patient, most patients have a combination.

Perioperative factors that may contribute to a higher risk of infection include device revision; use of temporary pacing leads before placement of the permanent device; lack of antibiotic prophylaxis before implantation; longer operative time; operative inexperience; development of postoperative pocket hematoma; and factors such as diabetes mellitus and long-term use of corticosteroids and other immunosuppressive drugs that impair wound healing at the generator pocket.^6–11

Device factors. Abdominal generator placement, use of epicardial leads, and complexity of the device play a significant role.^6,12,13 In general, implantable cardioverter-defibrillators and cardiac resynchronization therapy devices have higher rates of infection than permanent pacemakers.^2,14

Host factors. Diseases and conditions that predispose to bloodstream infection may result in hematogenous seeding of the device and its leads and are associated with a higher risk of late-onset infection. These include an implanted central venous catheter (for hemodialysis or other long-term access), a distant focus of primary infection (such as pneumonia and skin and soft-tissue infections), and invasive procedures unrelated to the CIED.^10,15

In general, contamination at the time of surgery leads to early-onset infection (ie, within weeks to months of implantation), whereas hematogenous seeding is a predominant factor in most patients with late-onset infection.¹⁶