International Journal of Cardiovascular ResearchISSN: 2324-8602

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Case Report, Int J Cardiovasc Res Vol: 3 Issue: 4

Infective Endocarditis in Chronic Hemodialysis: Involvement of the Left Heart or the Right Heart?

Y. Bentata1*, N. Ismailli2, H. Drissi3, S. Bekkaoui4, I. Haddiya1, A. Benzirar5, O. El mahi5 and A. Azzouzi6
1Department of Nephrology, Medical school, University Mohammed the First, Oujda, Morocco
2Department of Cardiology, Medical school, University Mohammed the First, Oujda, Morocco
3Department of Cardiology, Al Farabi Hospital, Oujda, Morocco
4Department of Nephrology, Al Farabi Hospital, Oujda, Morocco
5Department of Vascular Surgery, Medical school, University Mohammed the First, Oujda, Morocco
6Department of Anesthesia, Medical school, University Mohammed the First, Oujda, Morocco
Corresponding author : Dr. Yassamine Bentata
Avenue Hassan II, rue Kadissia, numero 12, Oujda, Morocco
Tel: 00212661289940; Fax: 00212536531919
E-mail: [email protected]
Received: March 13, 2014 Accepted: May 17, 2014 Published: August 12, 2014
Citation: Bentata Y, Ismailli N, Drissi H, Bekkaoui S, Haddiya I et al. (2014) Infective Endocarditis in Chronic Hemodialysis: Involvement of the Left Heart or the Right Heart?. Int J Cardiovasc Res 3:5. doi:10.4172/2324-8602.1000180

Keywords: Infective endocarditis; Chronic hemodialysis; Left heart; Right heart; Mortality

Keywords

Infective endocarditis; Chronic hemodialysis; Left heart; Right heart; Mortality

Objective

To determine the clinical, biological and echo cardio graphic characteristics, as well as the prognosis of IE in CHD.
In developed countries, the incidence of infective endocarditis(IE) is estimated at more than 300 cases per 100,000 people in chronic hemodialysis (CHD), while epidemiological data in developing countries remain unknown [1]. Such an incidence is extremely high compared to that found in the general population, and places the chronic hemodialysis patient as being at high risk for IE. However, as in the general population, IE of the left heart is the most frequent type in CHD and is usually found in more than 90% of cases, whereas involvement of the right heart is rare [2,3].

Methods and Findings

This is a retrospective study conducted at the center of nephrology and hemodialysis in Oujda, in the East of Morocco.
Over a period of 36 months, we compiled data on a series of six patients having developed IE out of a total of 161chronic hemodialysis patients, i.e.an incidence de 3.7%.The mean age of all patients was 35 ± 12 years. 83% of patients were male. 33.3% of patients had diabetes. The tricuspid valve was the valvular location of IE in 83% of cases. Blood cultures remained negative in 50% of cases. Mortality occurred in 50% of cases. The mean follow-up after hospital discharge for surviving patients was 19 ± 9 months. Table 1 reports the demographic, clinical, biological and echo cardiographic characteristics on admission and the evolutive characteristics of the six CHD patients having developed IE (Table 1).
Table 1: Demographic, clinical, biological and echocardiographic characteristics upon admission and evolution data of chronic hemodialysis patients presenting an infective endocarditis (n=6).

Discussion

It is important to note that in the major series published on IE in CHD, the authors do not differentiate between the initial and evolutive profile in relation to the location of the IE.
Contrary to what might be expected, the most frequent site of IE in the chronic hemodialysis patient is in the left heart and not the right heart, despite the particularity that these patients have central venous catheters.
Involvement of the mitral valve is found in 40 to 56% of cases, the aortic valve in 21 to 43% of cases and concomitant involvement of the mitral and aortic valves is found in 10 to 20% of cases [2-7]. Involvement of the tricuspid valve is rare and varies considerably from 0% to 20% depending on the series. Pulmonary valve involvement remains exceptional in CHD [2-8].
Mitral and aortic valves are the sites of early and significant changes in the course of chronic renal failure (CRF). These changes are related to alterations of phosphor calcic metabolism typically found in CRF and is manifested by valvular and peri valvular calcifications. These abnormalities continue to progress, all the more so because these valves exist in a cardiac system under high pressure, thus constituting the main risk factor for IE in CHD [9,10]. Immunodepression of the CHD patient and repeated manipulation of the vascular access also plays an important role in the development of IE. In contrast, the tricuspid and pulmonary valves do not undergo change during CRF because they are in a low-pressure cardiac system. Bacterial overgrowth during IE thus occurs more easily on the cardiac valves previously damaged, explaining the high prevalence of involvement of left-sided valves and the rarity of right-sided valvular involvement during IE in CHD.
The Duke criteria for the diagnosis of IE do not distinguish between left-sided endocarditis and right-sided endocarditis and do not take account of the particularities of the environment in which IE develops. While fever and heart murmur predominate in IE of the left heart, fever and lung impairment are the main signs of IE of the right heart. These non-specific signs explain the great delay in diagnosis.
In our series, the IE was an endocarditis of the right heart in more than 80% of cases, whereas its frequency does not exceed 20% in published series [2-7]. In some series, no right-sided involvement was found [3,7].Why was the frequency of right-sided IE so high in our series? Our patients were relatively young and 50% of them had chronic hemodialysis duration of less than three months. In this context, the left valves are still not very damaged and bacterial invasion at that location is more difficult. Moreover, all our patients had undergone several catheter insertions and had developed septicemias following a catheter-related infection. These episodes of septicemia were difficult to control with conventional antibiotic therapy due to the difficulty of identifying the causative organism prior to therapy and the virulence of these germs. This explains the frequency of IE during these episodes of septicemia. But the predominant involvement of the tricuspid valve is not yet completely understood in this context. Might the reason for this finding be related to the location of this valve? It is the first valvular line of contact with the blood flow arriving from the vena cavae and massively enriched with bacterial particles.
Moreover, the antibiotherapy previously received for the septicemia episodes made it difficult to identify the organism causing the IE, which explains the negative blood cultures found in 50% of cases in our series. In CHD, staphylococcus aureusis the main germ for IE of both the right heart and the left heart in more than 80% of cases and the frequency of methicillin - resistant S. aureusis constantly increasing, varying from 6% to 33% depending on the series [2-8].
Treatment of IE in CHD consists of antibiotic therapy targeting and adapted to the identified germ with removal of the vascular access, source of infection, whenever possible.
The mortality rate in CHD related to IE be 25 to 61% depending on the series, all cardiac sites included [2-8]. In our series the mortality rate was 60% for right-sided IE, an extremely high rate compared to the 5 % found in the general population. The vulnerabilities of the patients and diagnostic delays as shown by the size of vegetations revealed by echocardiography, explain to a great extent the high mortality in our series.
Strict respect of aseptic procedures during any manipulation of the vascular access and early detection of any infection of the vascular access continue to offer the only sure approaches to reducing the incidence of IE in CHD. Prevention is often difficult to achieve in a developing country where human and material resources remain inadequate. Under these circumstances, IE remains a daunting complication associated with a heavy burden of morbimortality.

Financial support

The authors report that they did not receive financial support for their article.

Conflict of interest statement

The authors report no conflicts of interest.

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