Clinical Profile of Isolated Right-Sided Infective Endocarditis

Background: The clinical profile of isolated right-sided endocarditis might have changed in recent years, owing to the increased frequency of intravenous drug abuse and the introduction of new diagnostic criteria. Besides, clinical characteristics of isolated right-sided endocarditis are not well known in Taiwan. Methods: One-hundred and forty-eight episodes of infective endocarditis in 136 consecutive patients admitted to a single tertiary referral center from January 1990 through July 2002 were evaluated retrospectively. Clinical variables were compared between group 1 (26 episodes of isolated right-sided endocarditis) and group 2 (122 episodes of non-right-sided endocarditis). Results: Patients in group 1 were younger, male-predominant, and had higher frequency of intravenous drug abuse as compared to group 2 (31.8 ± 6.3 vs. 45.8 ± 16.4 years, p < 0.001; 96.2% vs. 54.1%, p < 0.001; 84.6% vs. 4.9%, p < 0.001). Staphylococcus aureus was the most common causative microorganism in group 1 (73.1% vs. 22.1%, p < 0.001). Septic pulmonary embolism was frequently present in group 1 (65.4% vs. 0.8%, p < 0.001), and neurological complication was rarely noted in group 1 as compared to group 2 (3.8% vs. 29.8%, p = 0.006). In-hospital mortality rates were similar between both groups (23.1% vs. 22.1%). In group 1, some clinical variables, including platelet count, cardiac and renal complications, and non-cardiac shock, were significantly related to in-hospital death. Conclusions: The clinical profile of isolated right-sided endocarditis was significantly different from that of non-right-sided endocarditis. Our data suggest that the clinical profile of isolated right-sided endocarditis has undergone some changes in the last decade. In-hospital mortality in patients with isolated right-sided endocarditis was surprisingly high in this area. These findings might be useful in the management of this clinical condition.