Right-heart infective endocarditis: a propos of 10 cases

Right-heart infective endocarditis: a propos of 10 cases

Simon Antoine Sarr^1,&, Modou Jobe^1,2, Malick Bodian¹, Mbaye Sy¹, Mouhamadou Bamba Ndiaye¹, Adama Kane^1,3, Alassane Mbaye⁴, Maboury Diao¹, Moustapha Sarr¹, Serigne Abdou Ba¹

¹Service de Cardiologie, CHU Aristide Le Dantec, Dakar, Sénégal, ²Medical Research Council The Gambia Unit, Fajara, Gambia, ³Unité de Formation et de Recherche (UFR), Santé Université Gaston Berger, Saint Louis, Sénégal, ⁴Service de Cardiologie, Hôpital Général de Grand Yoff, Dakar, Sénégal

^&Corresponding author
Service de Cardiologie, CHU Aristide Le Dantec, Dakar, Sénégal

Infective endocarditis is defined as more or less the extensive damage to the endocardium caused by microorganisms (bacteria or yeast). The microbes are “grafted”during bacteraemiaon either a healthy or on a previously injured endocardium. Isolated endocarditis of the tricuspid valve or associated with pulmonary valve defect are less frequent than those of the left.They occur mostly among intravenous drug users, immune-compromised patients and those with congenital heart disease [1,2]. Their prevalence and characteristics in Africa are not well known.

We conducted a 10-year retrospective descriptive multicenter studyconducted from January 2000 to December 2010 in two cardiology departments (Aristide Le Dantec University Hospital and Principal Hospital of Dakar) in Dakar, Senegal. We studied the epidemiological, clinical and laboratory profiles of all patients with right-heart infective endocarditis, identified complications, analysed the various prognostic factors of the disease and assessed the management. All patients admitted with infective endocarditis of the right heart according to Duke's criteria: 2 major or 1 major and 3 minor, or 5 minor were included in the study. The data were entered and analysed using Epi Info version 3.5.1. We used Microsoft Excel 2007 for the quantitative data and to calculate averages.

During the study period, there were 10 cases of right-heart infective endocarditis representing 3.04% of infective endocarditis and 0.055% of all hospitalizations. The average age of our patients was 31 years (range from 9 to 70 years).There was a female predominance with a sex ratio (F:M) of 2.33. The socio-economic profile was low in 3 patients, and was average or good in 7 patients. Three patients had valvulo pathies(a mitral stenosis associated with a tricuspid insufficiency, a mitral valve disease associated with a tricuspid insufficiency, an aortic insufficiency associated with a tricuspid insufficiency). A case of atrial septal defect was noted, two parturients and a patient with single chamber pacemaker. One patient reported a fever of long duration. The data of the patients are summarized in Table 1. Clinically 7 patients had a tachycardia with an average heart rate of 127.62 beats/min; nine patients had fever with an average temperature of 38.5^°C (36.1 to 40^°C). A tricuspid murmur was found in 9 patients. There were in two patients, a mitral diastolic rumbling; and in one patient an aortic diastolic murmur.There was an interstitial pneumonia and pleural effusionin 3 and 4 cases respectively, four patients had congested hepatomegaly, a case of hemiparesis was noted. The port of entry was found to be oral in three cases, ENT in one case and urogenital in two cases. In one case pacemaker lead wasincriminated and in another an iatrogenic cause was found. Laboratory studies found anaemia in 9 cases with a mean hemoglobin of 9.5 g/dl (range from 6.6 g/dl to 11.2 g/dl); leukocytosis in 6 patients. The mean white blood cell count was 21,643.33 /mm³ (6400/mm³ to 44000/mm3). The erythrocyte sedimentation rate in the first hour was increased in four patients, a high CRP level in 8 patients (average of 171.19 mg/l), a hyperfibrinogenaemiain 7 patients with a mean of 6.91 g/l. Elevated serum creatinine was observed in 3 patients. 24h proteinuria was found in one case at 1.02 g/24 h and microscopic haematuria with an Addis count in 3 patients with respective values of 222 erythrocytes for the first 2 and 3194 erythrocytes for the third.

Blood cultures were performed in 9 patients with an average of 2 sets/patient and were positive in 3 cases. Germs isolated respectively were Streptococcus pneumoniae, Staphylococcus aureus and Pseudomonas aeruginosa. Urinalysis was carried out in 8 patients but was positive in one case. ECG found two cases of atrial fibrillation, a patient with an S1Q3 pattern with background tachycardia. All patients had benefited from a transthoracic Doppler echocardiography and two of whom also had a trans-oesophageal echocardiography. A vegetation or more were found in all patients. In 9 but 1 case, the vegetations were localized on the tricuspid valve, the tricuspid and pulmonary level in one case. Two patients had a large mobile vegetation at the tricuspid valve. In one patient we found a large and numerous vegetationsin clusters, located at the pulmonary and tricuspid valves. For the remainder of the patients, we found smaller multiple vegetations. Chest CT scan was performed in one patient in whom pulmonary embolism was suspected which revealed a bilateral pulmonary embolism associated with several areas of pulmonary infarction. Antibiotic therapy was administered in all patientsusing IV route. Doses were adjusted according to the weight, with renal function taken into account. It was a bi-antibiotherapyin 8 cases involving a gentamicin dose of 3mg/kg/day for an average of 12 days, which was combined respectively with ampicillin in 4 cases, ceftriaxone in four cases, oxacillin in two cases. The outcome was favorable in four patients. However it was associated with complications in others. There were three cases of renal impairment, heart failure in two patients and one case of pulmonary embolism.There was one mortality occurring in a 70-year-old who died from sepsis, 8 days of hospitalization. The average hospital stay was 39.7 days (8 to 90 days).

Right-heart endocarditis is less common. Its prevalence varies between 5 to 10% depending on the series [1]. Lejkó-Zupanc et al in a paper on 205 patients with endocarditis conducted in 1999, reported 13 cases of right heart endocarditis. It is common to find IV drug users in patients with a right heart endocarditis with the incidence in this population varying from 3 to 5%. In our series, no history of substance abuse was reported. The authors found four patients whose cause was iatrogenic (central venous catheter, pacemaker probe). In four others, there was an immune-compromised status (alcoholic cirrhosis, cancer) [2]. Genital port of entry is not uncommon [3]. Kimbally-kaky also reported 7 cases of endocarditis of the right-heart from illegal abortions in an aseptic environment [4]. We noted a difference in age and sex ratio between our series and those reported in the literature [5]. This is explained by differences in etiologic factors including rheumatic heart disease. Forms of endocarditis in congenital heart disease have been described [6]. Blood cultures are a vital test in the diagnosis of endocarditis. They may however be negative, 14% of cases by Delahaye [7]. The low rate of positive blood cultures found in our series is similar to other series in Africa [4].This finding could be explained by prior antibiotic treatment in most patients with fever, technical conditions in carrying out blood cultures (unsanitary conditions or sample delivery to laboratories), slow growing germs and sometimes a lack of culture plates in our laboratories. Doppler echocardiography plays a major diagnostic role [1]. Germs implicated in a French series were streptococcus in 48% of cases and staphylococcus in 29% [8]. Heart failure may complicate infective endocarditis. It is more common in African series [9] than in the West [10]. One of the most dreaded complications is probably septic pulmonary embolism. Lejkó-Zupanc et al reported in 9 cases out of 13 patients with endocarditis of the right heart. The image most frequently found was that of a pulmonary infiltrate and not that of a pulmonary infarction [1]. Similarly, renal involvement is not uncommon and should be monitored. Its existence, just as advanced age, would be a poor prognostic factor [9]. Mortality in infective endocarditis is still significant between 16-27%, despite the progress in terms of antibiotic therapy [6].

Right heart infective endocarditis is uncommon. This is a serious condition because of its potentially fatal complications. Circumstances of occurrences and port of entry are variable.

The authors declare no competing interest

SAS, MB, and ACMY designed the study protocol, participated in the data collection and contributed in analyzing the data and writing of the draft manuscript. MJ, MBN, AK, and AM participated in data analysis and critically revising the manuscript for important intellectual content.MD, MS and SAB participated in study design and in data analysis. All authors have read and approved the final version of the manuscript.

Table 1: summary of data of ten patients

1. Akinosoglou K, Apostolakis E, Marangos M et al. Native valve right sided infective endocarditis. Eur J InternMed. 2013; 24(6):510-519. PubMed | Google Scholar


2. Lejko-Zupanc T, Kozelj M, Kranjec I et al.Right sided endocarditis: clinical and echocardiographic characteristics. J Clin Basic Cardiol. 1999; 2(1):81-84. PubMed | Google Scholar


3. Brook I. Infective endocarditis caused by anaerobic bacteria. Arch Cardiovasc Dis. 2008; 101(10): 665:676. PubMed | Google Scholar


4. Kimbally-Kaky G, Bouramoue C. Apport de l'échocardiographie dans l'endocardite infectieuse (à propos de 36 cas). Cardiologie tropicale. 2001; 27(106):23-26. PubMed | Google Scholar


5. Rouveix E, Witchitz S, Bouvet E et al.Tricuspid infective endocarditis: 56 cases. Eur Heart J. 1984; 5(suppl C):111-116. PubMed | Google Scholar


6. GonçalvesAM, Correia A, Falcão LM. Tricuspid valve endocarditis in a patient with congenital heart disease.Rev Port Cardiol. 2013; 32(1):53-58. PubMed | Google Scholar


7. Delahaye F, Goulet V, Lacassiv F et al. Incidence caractéristiques démographiques, cliniques, microbiologiques et évolution de l'endocardite infectieuse en France en 1990-1991. Med Mal Infect. 1992; 22: 975-976. PubMed | Google Scholar


8. Société Française de Cardiologie. Prophylaxie de l'endocardite infectieuse: révision de la conférence de Consensus de Mars 1992; recommandations 2002. Med Mal Infect. 2002; 542-552. Google Scholar


9. Sossoumihen LLD. Les endocardites infectieuses au CHU de Dakar, une étude rétrospective à propos de 35 cas. Thèse Méd. Dakar. 1999 n°30. Google Scholar


10. Witchitz S, Bouvet E, Petitpretz P et al. Les endocardites infectieuses tricuspidiennes.3èmes entretiens cardiologie. 1983 ; 89-95 In: JP Beix. Pathologie de la valve tricuspide.Paris. Masson. Google Scholar