Case-control study of potential culprit procedures for infective endocarditis in an Egyptian Tertiary Care Centre

Infective endocarditis (IE) is associated with substantial morbidity and mortality. The numbers of patients with chronic predisposing medical comorbidities have increased as has the commensurate risk of exposure to nosocomial bacteremia. However, there are conflicting views as to the significance of bacteremia caused by interventional procedures in the existing IE clinical guidelines. Aim of the work: Many IE risk factors have been postulated, but formal evaluation of these risk factors is lacking in Egyptian tertiary care Centers. In this study, we test the hypothesis that underlying medical conditions, not culprit procedures, are the most important risk factor for development of IE in an Egyptian tertiary care center. Patients and methods: We matched 175 patients with definite IE from the IE database of Cardiology Department at Cairo University Hospital with175 control cases without IE, matched for age, sex, and underlying heart disease.Demographic and clinical data, comorbidities and potential culprit procedures during the 3 months prior to the diagnosis of IE were recorded in both groups. Continuous and categorical variables were compared using a two-tailed t-test and Pearson’s chi-square analysis, respectively. Correlations were tested using Pearsosn’s correlation coefficient. Results: Host-related risk factors included renal impairment (12% vs. 1.1%, p < 0.001), renal dialysis (6.3% vs. 0.6%, p = 0.003) and prior episode of IE (5.1% vs. 1.1%, p = 0.03). Procedure-related risk factors included a history of hospitalization for at least 24 hours in the preceding 3 months, (42.3% vs. 14.9%, p < 0.001), and use of peripheral intravenous (IV) line (18.2% vs. 8.2%, p = 0.005). Any form of dental procedure was not a risk factor for IE.Staphylococcus species especially Staphylococcus aureus was the most prevalent causative and procedure-related microorganism (27.3%), followed by Streptococcus species in 15.9% of cases. Conclusions: Hospitalization for at least 24 h within the preceding 3 months and peripheral IV line placement during that hospitalization were significant risk factors for IE. Our study also confirmed renal impairment and prior IE as risk factors. Staphylococci were the predominant causative microorganisms.These results suggest a nosocomial source of infection and call for reinforcement of infection prevention interventions in Egyptian hospitals especially in high- risk patients