Infective endocarditis in dialysis patients: new challenges and old

BACKGROUND: Since the 1960s chronic hemodialysis (HD) has been recognized as a risk factor for the development of infective endocarditis (IE). Historically, it has been particularly associated with vascular access via dual lumen catheters. We wished to examine the risk factors for, and consequences of, IE in the modern dialysis era. METHODS: Cases of IE (using the Duke criteria) at St. Thomas' Hospital (1980 to 1995), Guy's (1995 to 2002), and King's College Hospitals (1996 to 2002) were reviewed. RESULTS: Twenty-eight patients were identified as having developed IE (30 episodes of IE). Twenty-seven patients were on long-term HD and one patient was on peritoneal dialysis (PD). Mean age was 54.1 years, and mean duration of HD prior to IE was 46.3 months. Eight patients were diabetic. Primary HD hemoaccess was an arteriovenous fistula (AVF) in 41.3%, a dual-lumen tunneled catheter (DLTC) in 37.9%, a polytetrafluoroethylene (PTFE) graft in 10.3%, and a dual- lumen non-tunneled catheter (DLNTC) in 4%. The presumed source of sepsis was directly related to hemoaccess in 25 HD patients: DLTC in 48%; AVF in 32%; PTFE in 12%; and DLNTC in 4%. Staphylococcus aureusincluding methicillin resistant Staphylococcus aureus (MRSA)] was present in 63.3%. The mitral valve was affected in 41.4% of patients, aortic valve in 37.9% of patients, and both valves were affected in 17.2% of patients. Of note, 51.7% of patients had an abnormal valve before the episode of IE. In 15 cases surgery was undertaken. Fourteen patients survived to discharge, and 12 survived for 30 days. In 15 cases antibiotic treatment alone was employed; in this case, eight patients died and seven survived to discharge. CONCLUSION: This is the largest reported confirmed IE series in dialysis patients. Infective endocarditis in HD patients remains a challenging problem-although hemoaccess via dual-lumen catheters remains a significant risk, many cases developed in patients with AVFs and this group suffered the greatest mortality. An abnormal valve (frequently calcified) was another risk factor; because valve calcification is now common after 5 years on dialysis, more effort in preventing this avoidable form of ectopic calcification may reduce the risk of developing IE.