OBJECTIVE

To ascertain the predominant characteristics of patients receiving long-term dialysis who develop infective endocarditis (IE).

PATIENTS AND METHODS

We reviewed the records of all chronic hemodialysis patients 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 episodes 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 years; 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 analysis included 10 episodes of IE (occurring in 9 patients) within the Mayo Clinic Dialysis System during which time 223,358 hemodialysis treatments were delivered, giving a rate of 10 IE episode per 223,336 hemodialysis treatments. Among all 20 IE episodes, there were 14 synthetic arteriovenous grafts, 4 permanent venous dialysis catheters, 2 temporary venous dialysis catheters, and 2 native arteriovenous fistulas (2 accesses in 2 patients), and access 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 causative organisms for IE were Staphylococcus aureus in 8 cases, Enterococcus sp in 4 cases, viridans streptococcus in 3 cases, Staphylococcus epidermidis in 2 cases, and 1 case each of Streptococcus bovis, group G beta-hemolytic streptococcus, and Aspergillus sp. The mitral valve was involved in 9 cases, the aortic valve was involved in 5 cases, and the tricuspid and pulmonic valves were involved in 1 case each. Patient survival (after the first episode of IE) was 71% at 30 days; 53% at 60 days; and 35% at 1 year. Echocardiography was performed in 19 episodes of IE. The transthoracic echocardiogram was 62.5% sensitive and 40% specific for the presence of definite or probable vegetations. Univariate analysis for factors affecting 60-day survival show that presence of right-sided IE, vegetation size greater than 2.0 cm3, diagnosis of diabetes mellitus, and initial leukocyte count greater than 12.5 x 10(9)/L were poor prognostic factors. Aortic valve involvement carried 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 likely to develop IE than patients with native arteriovenous fistulas. Transesophageal echocardiography is a preferred echocardiographic study for suspected cases of IE. Prolonged antibiotic therapy is needed for all patients, and close monitoring is needed for patients with right-sided IE, large vegetations, diabetes mellitus, and an elevated leukocyte count.