Infective endocarditis in patients receiving chronic hemodialysis: A 21-year observational cohort study in Denmark.

BACKGROUND: Chronic hemodialysis is a risk factor for invasive bacterial infections. We conducted a nationwide study of risk and mortality of infective endocarditis (IE) among patients undergoing chronic hemodialysis.

METHODS: In this observational cohort study, patients with end-stage renal disease who initiated hemodialysis in Denmark during 1990 to 2010 were matched on age, gender, and municipality with up to 19 population controls. We extracted information on first admissions with IE, comorbidity, and arteriovenous fistula surgery from medical administrative databases. Incidence rates (IRs) of IE were compared between patients undergoing hemodialysis and population controls using Poisson regression. Risk factors for IE were assessed by Cox regression.

RESULTS: IE was diagnosed in 150 of 9392 patients undergoing hemodialysis (IR: 6.83 per 1000 person-years, 95% confidence interval [CI]; 5.82-8.01) and 250 of 176,369 population controls (IR: 0.18 per 1000 person-years, 95% CI; 0.16-0.20) yielding an incidence rate-ratio of 38.1 (95% CI; 31.2-46.7). Among patients undergoing hemodialysis, absence of arteriovenous fistula surgery was associated with increased risk of IE (hazard ratio [HR] = 1.57; 95% CI; 1.09-2.27) after adjusting for age, sex, valvular disease, diabetes and period of first hemodialysis. Age ≥70 years was associated with a lower risk of IE (HR = 0.59; 95% CI 0.37-0.93). The 90-day all-cause mortality following diagnose of IE was 27% (95% CI; 20-35) for patients undergoing hemodialysis and 23% (95% CI; 18-29) for controls.

CONCLUSIONS: Patients undergoing hemodialysis have markedly elevated risk of IE compared to the general population. Future challenges will be to develop strategies to prevent IE, to reduce IE-related morbidity and mortality in this vulnerable population.