RESUMEN
BACKGROUND AND AIM OF THE STUDY: The echocardiographic findings, microbiological profiles, risk factors for mortality, and outcomes of intravenous drug (IVD) users and non-users with infective endocarditis (IE) in Taiwan were evaluated. METHODS: In this retrospective study, the charts of IVD users and non-users who were treated for IE between January 1999 and December 2009 in a hospital in Taiwan were reviewed. RESULTS: A total of 108 patients (including 26 IVD users) with definite diagnoses of IE according to the modified Duke criteria were enrolled in the study. Typically, IVD users were significantly more likely to be infected with Staphylococcus aureus (p < 0.001). A greater proportion of IVD users had higher levels of hemoglobin (84.6% versus 62.2%; p = 0.033) and a lower percentage had high platelet counts (42.3% versus 73.2%; p = 0.004) when compared to non-users. A higher percentage of IVD users had hepatitis C compared to non-users (73.1% versus 11%; p < 0.001). Most non-users had vegetations in the mitral and aortic valves (40/74; 54.1% and 35/74; 47.3%, respectively), whereas IVD users had significantly more vegetations in the tricuspid valve (10/18; 55.6%). The overall in-hospital mortality rate was 33.3% (36/108), but the rate for IVD users (11.5%; 3/26) was significantly lower than that for non-users (40.2%; 33/82) (p = 0.007). Multivariate analysis showed that age > 40 years and serum creatinine level > or = 1.2 mg/dl were significantly associated with higher mortality [odds ratios (ORs) 1.06 and 7.49, respectively; p < 0.001 for both]. When the entire patient group was analyzed, a significantly better survival was associated with IVD use and surgical intervention (ORs 0.19 and 0.11; p = 0.012 and 0.011, respectively). CONCLUSION: The clinical features, microbiological spectra and outcomes of IVD users with IE were different from those of non-users. Among all patients, a higher age and elevated serum creatinine levels were significant risk factors for mortality, whereas IVD use and surgical intervention were associated with higher rates of survival.