Infective endocarditis in patients receiving long-term hemodialysis

Objective: To ascertain the predominant characteristics of patients receivi ng long-term dialysis who develop infective endocarditis (IE). Patients and Methods: We reviewed the records of all chronic hemodialysis p atients who had IE at Mayo Clinic, Rochester, Minn, between 1983 and 1997. Results: Twenty episodes of IE occurred in 17 patients. One patient had 3 e pisodes of IE, and 1 patient had 2 episodes of IE; each episode was caused by a different organism. The mean +/- SD age of our patients was 63+/-11 ye ars; there were 13 males; 6 patients had diabetes mellitus; and the mean +/ - SD duration of hemodialysis prior to IE was 24.2+/-20.5 months. This anal ysis included 10 episodes of;IE (occurring in 9 patients) within the Mayo C linic Dialysis System during which time 223,358 hemodialysis treatments mer e delivered, giving a rate of 10 IE episode per 223,336 hemodialysis treatm ents. Among all 20 IE episodes, there were 14 synthetic arteriovenous graft s, 4 permanent venous dialysis catheters, 2 temporary venous dialysis cathe ters, and 2 native arteriovenous fistulas (2 accesses in 2 patients), and a ccess had been in place for a mean +/- SD of 15.9+/-18.6 months. The portal of infection was the hemodialysis access in 13 episodes of IE. The causati ve organisms for IE were Staphylococcus aureus in 8 cases, Enterococcus sp in 4 cases, viridans streptococcus in 3 cases, Staphylococcus epidermidis i n 2 cases, and 1 case each of Streptococcus bovis, group G beta-hemolytic s treptococcus, and Aspergillus sp. The mitral valve was involved in 9 cases, the aortic valve was involved in 5 cases, and the tricuspid and pulmonic v alves were involved in 1 case each. Patient survival (after the first episo de of IE) was 71% at 30 days; 53% at 60 days; and 35% at 1 year. Echocardio graphy was performed in 19 episodes of IE. The transthoracic echocardiogram was 62.5% sensitive and 40% specific for the presence of definite or proba ble vegetations. Univariate analysis for factors affecting 60-day survival show that presence of right-sided IE, vegetation size greater than 2.0 cm(3 ), diagnosis of diabetes mellitus, and initial leukocyte count greater than 12.5 x 10(9)/L were poor prognostic factors. Aortic valve involvement carr ied a better prognosis. Conclusions: Infective endocarditis in hemodialysis patients is relatively infrequent but has a high mortality. Patients with synthetic intravascular dialysis angioaccess (synthetic grafts and venous catheters) are more likel y to develop IE than patients with native arteriovenous fistulas. Transesop hageal echocardiography is a preferred echocardiographic study for suspecte d cases of IE, Prolonged antibiotic therapy is needed for all patients, and close monitoring is needed for patients with right-sided IE, large vegetat ions, diabetes mellitus, and an elevated leukocyte count.