**6. Social implications**

all artificial material. Obviously, this can be quite challenging from not only a technical standpoint when the patient is quite sick but also how to support a patient that may be pacemaker-dependent in the setting of an infected pacemaker lead system. While many such devices can be removed percutaneously, there is often concern that large vegetations or lead systems that are firmly adherent to cardiac structures such as the tricuspid valve may require open heart surgery with direct removal [16]. Again, such cases illustrate the importance of a multidisciplinary team approach to not only the timing of interventions but also the specific

The greater challenge is the timing of surgical intervention in patients who may require valve surgery—either repair or replacement—especially in the setting of associated other intracardiac pathology. Historical paradigms of prolonged courses of antibiotics and delayed surgical intervention, often after completion of a course of antibiotics, have been challenged recently as current European and American Society guidelines are tending to advocate early and aggressive surgical intervention. It was believed previously that early surgery and patients with active infections and vegetations were associated with a prohibitive risk for reinfection and postoperative complications from operating on septic patients. This was the rationale for delayed surgery after a prolonged course of antibiotics [17]. However, this approach was frequently criticized as selecting only those patients who survived complication free to complete their course of antibiotics, while potentially undertreating those patients who may have benefited from aggressive debridement and infection source control and who ultimately died of either overwhelming septic complications or catastrophic neurological events. A randomized trial of 37 patients with left-sided endocarditis, severe valvular disease, and large vegetations compared early surgical intervention with conventional medical therapies and potential delayed interval surgery and concluded that early surgery had a significant impact in reducing further embolic events and death [18]. Unfortunately, as a function of the nature of the disease combined with associated comorbidities, randomized trials dealing with surgical management of infected endocarditis can be very difficult. Current guidelines acknowledge this fact and base their recommendations on the growing body of literature that consists predominantly of small series and high-quality observational studies [19]. Nevertheless, the current guidelines suggest early surgical intervention in those patients who present with the

procedures that may be required to remove the offending hardware.

**1.** Valvular dysfunction resulting in signs or symptoms of acute heart failure.

**2.** Early surgery is recommended with those patients with fungal infections or highly

**3.** Those patients who present with cardiovascular complications directly associated with their infections, including new heart block, aortic or root or annular abscess cavities, or penetrating infectious complications such as fistula, might benefit from early surgery.

**4.** Surgery is indicated in the setting of persistent bacteremia or fever greater than 5–7 days in the absence of another identifiable primary source in the setting of appropriate targeted

following characteristics:

6 Contemporary Challenges in Endocarditis

resistant organisms.

antibiotic therapy.

Without doubt, the greatest challenges in dealing with patients with endocarditis are the growing population of patients presenting with a history of intravenous drug abuse especially heroin. Recent data suggest a twofold increase in the number of active users of heroin between 2006 and 2013 [24]. The growing epidemic of drug abuse, worldwide, cannot be ignored nor denied. Endocarditis in the setting of IV drug abuse is particularly difficult to manage, while the etiology is often the use of infected needles or contamination of the drugs being directly injected into the vascular system. Patients who present with infections also have other acquired comorbidities associated with their substance abuse that challenge their management and long-term prognosis. Hepatitis B and C as well as human immunodeficiency virus are often encountered in this patient population [25]. Chronic pain syndromes as well as their underlying drug addiction and associated personality and psychological disorders not only makes this population difficult to manage in the hospital setting but also raises the concern of long-term compliance with medical therapies. While there might be a general reluctance, for example, to use mechanical valves in younger patients, concerns about compliance with anticoagulation often leaves little choice. This is particularly true when patients present with a history of hepatitis and their long-term liver function (critical for clotting factors and Coumadin management) is unpredictable. Without doubt, this population is at risk for recurrent problems secondary to their substance abuse history. A recent study by Kim and colleagues illustrate the scope of this problem. Between 2002 and 2014, there was a twofold increase in the number of patients requiring surgery for infected endocarditis at their institution space (14.8% in 2002–26% in 2012). Of the 436 patients studied, over a mean follow-up of 29 months adverse events occurred in 20% including 10% developing re-infections—often as a function of continued substance abuse. While their findings demonstrated a lower operative mortality in patients with drug abuse predominately as a function of their age, propensity score analysis indicated that IV drug abuse was associated with an almost fourfold increase in valve-related complications and a 6.2-fold increase in reinfection. Because of the concerns of noncompliance, relapse of drug abuse, and poor socioeconomic status of many of these patients, surgical intervention in the setting of long-standing drug abuse is often viewed as intervening on an end-stage, often inherently fatal, disease. Some clinicians viewed attempts at curing these patients of their infections and substance abuse as being futile. In fact, while often discussed but rarely written, most programs will refuse surgical re-intervention except for extenuating circumstances in those patients who continue to demonstrate ongoing drug abuse who subsequently developed recurrent prosthetic valve infections. Prior to refusing potentially lifesaving, but high-risk, surgery in such patients or referral to palliative care, an open and honest discussion with an Institutional Ethics Team might be indicated.

Because of the cost of therapy that often includes prolonged hospitalizations, extensive diagnostic evaluations, complex surgery, or multiple surgical interventions, and often a prolonged recovery that can also be challenged by baseline comorbidities, disease complications, and access to potentially limited resources, the growing epidemic of endocarditis is clearly a problem. This is all in the background of whether the social programs that reduce the risk of infections, such as prophylactic antibiotics prior to dental procedures, are cost effective or even reduce the risk of infections at all [26, 27]
