A case-control study: are urological procedures risk factors for the development of infective endocarditis?

Objective: To evaluate the association between urological procedures and the development of infective endocarditis (IE), as there are case-reports linking urological procedures to IE but evidence of a causal relationship is lacking and no major guidelines advise prophylaxis to prevent development of IE during transurethral urological procedures. No case-control study has been undertaken to examine the relationship between urological procedures and the development of IE.

Patients And Methods: Retrospective evaluation of the IE database at our institution. The population consisted of patients diagnosed with enterococcal, staphylococcal, Streptococcus bovis-group and oral streptococcal IE over a 10-year period. Possible risk factors for the development of IE, including urological procedures were collected. A case-control design was used and univariable and multivariable analyses were carried out. Missing data was accounted for using the multiple imputations method.

Results: We included 384 patients with IE. There was a statistical association between the development of enterococcal IE and preceding urological procedures (odds ratio 8.21, 95% confidence interval 3.54-19.05, P < 0.05). Increasing age and being an intravenous drug user were also associated with enterococcal IE. Haemodialysis and the presence of an intracardiac device were associated with the development of coagulase-negative staphyloccal IE.

Conclusion: This is the first study to show a statistical association between urological procedures and the development of IE. The bacteraemia leading to IE may be a result of the urological procedures or a consequence of the underlying urological pathology causing recurrent subclinical bacteraemias.