Right-Sided Infective Endocarditis in Korea

ABSTRACT

BACKGROUND AND OBJECTIVES: Right-sided infective endocarditis (RtIE) occurs in about 5-10% of total infective endocarditis cases. In western countries, many cases of RtIE are related to drug addiction. However, there been only scant reports of right-sided infective endocarditis in Korea. The aim of the study was to identify the clinical characteristics of RtIE, such as frequency, predisposing risk factors, causative organisms and in-hospital mortality in Korea. SUBJECTS AND METHODS: All episodes diagnosed as infective endocarditis, between 1989 and 2003, at the Asan Medical Center were retrospectively reviewed using Duke's criteria. A total of 308 patients were diagnosed as infective endocarditis. RESULTS: RtIE was found in 34 patients (11.0%), with a mean age of 44.1+/-15.0 years. Fifteen patients had congenital heart diseases. However, several in-hospital invasive procedures and skin injuries were the most common predisposing risk factors in patients with uncorrected congenital heart disease (group A), whereas unknown causes were most common in patients without uncorrected congenital heart disease (group B). The most common causative organisms in groups A and B were Streptococcus viridans (6/15, 40%) and Staphylococcus aureus (13/19, 68.4%), respectively. In group A, the location of vegetations was variable according to the turbulent flow, but was exclusively at the tricuspid valve in group B. There were 6.7% (1/15) and 26.3% (5/19) inhospital mortalities in groups A and B, respectively (p=0.196). CONCLUSION: No drug addict with RtIE was seen. The most important predisposing risk factor in patients with RtIE was the presence of uncorrected congenital heart disease. The predisposing risk factors, causative organisms and the locations of vegetation in patients with RtIE differed according to the patient's uncorrected congenital heart disease.