Mortality risk factors in chronic haemodialysis patients with infective endocarditis

It is well documented that infective endocarditis (IE) is strongly associated with morbidity and mortality in haemodialysis (HD) patients. Less clear are the mortality risk factors for IE, particularly in an urban African-American dialysis population.

IE patients were identified from the medical records for the period from January 1999 to February 2004 and confirmed by Duke criteria. The patients were classified as 'survivors' and 'non-survivors' depending on in-hospital mortality, and risk factors for IE mortality were determined by comparing the two cohorts. Survivors were followed as out-patients with death as the endpoint.

A total of 52 patients with 54 episodes of IE were identified. A catheter was the HD access in 40 patients (74%). Mitral valve (50%) was the commonest valve involved, and Gram-positive infections accounted for 87% of IE. In-hospital mortality was high (37%) and valve replacement was required for 13 IE episodes (24%). On logistic regression analyses, mitral valve disease [P = 0.002; odds ratio (OR) = 15.04; 95% confidence interval (CI) = 2.70-83.61] and septic embolism (P = 0.0099; OR = 9.56; 95% CI = 1.72-53.21) were significantly associated with in-hospital mortality. Using the Cox proportional hazards model, mitral valve involvement (P = 0.0008; hazard ratio 4.05; 95% CI = 1.78-9.21) and IE related to drug-resistant organisms such as methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus sp. (P = 0.016; hazard ratio 2.43; 95% CI = 1.18-5.00) were associated with poor outcome after hospital discharge.

IE was associated with high mortality in our predominantly African-American dialysis population, when the mitral valve was involved, or septic emboli occurred and if MRSA or VRE were the causal organisms.