**3. The ESRD patients in dialysis**

**1. Introduction**

122 Contemporary Challenges in Endocarditis

**2. Epidemiology**

between authors and clinical centers [6].

that this leads to over 8400 deaths [7].

no significant decrease observed since the 1960s [1].

vary from the developed countries to developing countries [3, 4].

patients, which can be performed in any health care facility.

and diagnostic and treatment challenge for clinicians and surgeons [5].

The epidemiology of infectious endocarditis (IE) has changed over the past five decades, with many contributing factors for the increasing incidence. The survival rate of chronically ill patients with nephropathy and cardiac patients has increased by transplanting or immunosuppressing, which is a consequence of medical advances. All risk factors in certain subgroups of patients are associated with the use of intracardiac or intravascular devices, prosthetic implants or catheters, and immunosuppressive drugs, causing increased health care-related infections. Despite advances in medicine, in-hospital mortality rate of IE remains high with

Despite many scientific efforts that have been made to realize the magnitude of this problem in different regions of the world, assessing its incidence is difficult because of the few epidemiological studies that currently exist globally; the incidence of endocarditis may vary from one country to another, between 1.5 and 11.6 per 100,000 inhabitants. Apart from its incidence, it is recognizing that this is a condition that involves high morbidity and mortality [2].

Infective endocarditis (IE) in patients with end-stage renal disease (ESRD) is a problem that continues *in crescendo* worldwide, with high morbidity and mortality, but in developing countries, the problem is more alarming due to various factors such as underdevelopment, economic inequality, and limitations in health care systems. The treatment has not changed in recent decades and instead epidemiological characteristics show very specific changes that

Some authors have proposed modifications in the IE classification to address hemodialysis (HD) patients in a different category, because they represent a crescent population of IE patients

This chapter highlights some identified differences as well as some regional differences between developed and developing countries, and provides strategies to reduce IE in HD

The precise incidence of IE is difficult to ascertain because case definition has varied over time

IE varies according to the region. Limited data suggest that the characteristics of IE in lowincome countries differ from those in industrialized countries. It is estimated that over 33,700 rheumatic heart disease (RHD)-related IE cases arise each year in developing countries and

Many literature reports and a few retrospective series have been presented on infective endocarditis in the hemodialysis population. The true incidence of IE in HD patients is, at best, an underestimate in retrospective studies. It is reported that it occurs in 6% of HD patients.

The main risk factors for HD patients to get IE are recurrent bacteremia, uremia, immunesystem damage, and premature degeneration of the heart valves caused by abnormalities in calcium and phosphorus homeostasis and chronic inflammation [8].

In 2006 the National Kidney Foundation established their guideline recommendations to select and place the access of HD being first choice arteriovenous fistula followed by fistula with synthetic graft leaving tunneled catheters and nontunneled as an alternative only when you do not have any of the first two options. Despite the goal since these guidelines were made in 2006 to have 50% of HD in AVF, this percentage has been achieved only in some European countries, but in North America, it has less percentage than what the guidelines suggest [11].

Mechanical and infectious complications most frequently limit the use of a central venous catheter (CVC). Infection is the most common cause of morbidity and the second cause of death after cardiovascular disease in HD patients. The incidence of catheter-related bacteremia (CRB) in HD patients depends on the type and location of the CVC, the characteristics of the population, insertion techniques and safety measures, and manipulation of HD catheters in each center. The CRB rate in nontunneled CVC is between 3.8 and 6.6 episodes/1000 days of the use of CVC and between 1.6 and 5.5 episodes/1000 days of the use of tunneled CVC. The use of a tunneled CVC carries an increased risk of bacteremia 7 to 20 times compared to the arteriovenous fistulas (AVF) [12].

The International Collaboration on Endocarditis Prospective Cohort Study conducted a prospective cohort study with 2781 adults diagnosed with infective endocarditis in 58 hospitals in 25 countries from June 2000 to September 2005, which reported an IE incidence of 21% in chronic HD patients (more than 90 days) and 25% chronic IV access in North America; 8% in chronic HD patients and 5% chronic IV access in South America; and 4% in chronic HD patients and 5% chronic IV access in Europe [13].

The above statistics differ from those reported by other authors from different parts of the world; UK presents a lower incidence of reported cases of endocarditis; and Doulton Timothy et al. reported a series of 28 cases of IE using the Duke criteria, at St. Thomas' Hospital (1980–1995), Guy's (1995–2002), and King's College Hospitals (1996–2002). Of this 28 patients, 27 patients were on chronic HD and 1 in peritoneal dialysis (PD) patient. 40% of the HD patients were treated with AVF's and the AVF was the definite or suspected site of entry for the causative organism in eight cases of IE representing the 26.6% of the total of patients with IE. The presumption that the AVF was the source of bacteremia in these episodes is supported by the fact that the causative organism in seven episodes was commensal skin pathogens *Staphylococcus aureus* (*S. aureus*) in six patients and *Staphylococcus epidermidis* (*S. epidermidis*) in one patient [3]. In contrast, Jones et al. conducted a retrospective study between the years 1998 and 2011. Forty-two patients were identified with developed IE out of a total incident dialysis population of 1500 over 13 years. Ninety-five percent of patients (40/42) were on long-term HD and five percent (2/42) on PD. Mean patient age was 55.2 years (IQR: 43–69), and the mean duration of HD prior to IE was 57.4 months. Primary HD access at the time of diagnosis was an AVF in 35% (14/40), a dual-lumen tunneled catheter (DLTC) in 55% (22/40), and a dual-lumen nontunneled catheter (DLNTC) in 10% (4/40). *S. aureus*, including methicillin-resistant *S. aureus* (MRSA), was present in 57.1% (24/42) [14, 15].
