Ohide Otome1, Stephen Guy2, Adrian Tramontana2, Garry Lane2, Harin Karunajeewa3. 1. Infectious Diseases Department, Western Hospital, Melbourne, Vic., Australia. Electronic address: o.hide@hotmail.com. 2. Infectious Diseases Department, Western Hospital, Melbourne, Vic., Australia. 3. Department of Medicine, Western Hospital, Melbourne, Vic., Australia; North West Academic Centre, The University of Melbourne, Western Hospital, Melbourne, Vic., Australia; Walter and Eliza Hall Institute, Melbourne, Vic., Australia.
Abstract
BACKGROUND: Previously described prognostic markers in right-sided infective endocarditis (RSIE) include vegetation size ≥1cm, fever for more than three weeks, cardiac failure and severe sepsis. This study aimed to evaluate effectiveness of medical therapy for vegetations ≥1cm and explore determinants of outcome in a representative population of intravenous drug users (IDUs) at a metropolitan Australian health service. METHODS: Retrospective review of consecutive IDUs presenting to our institution with native-valve RSIE (by modified Duke criteria) over seven years (2005-2011). Data recorded included echocardiographic estimation of maximal vegetation diameter (classified as < or ≥1cm). Relationships between vegetation size and specified outcomes of death, septic shock, recurrence and relapse were examined by Chi-squared testing. RESULTS: Of 49 episodes five (10%) were managed surgically and a further four (8%) were lost to follow-up and excluded from the analysis. Of the remaining 40 evaluable medically treated patients (median age 28, range 20-55), 37 (93%) cultured methicillin-sensitive S. aureus and all had tricuspid valve involvement. Of 24 with vegetations ≥1cm, three died (mortality 13%) compared with one (6%) in 16 medically treated patients with vegetations <1cm (p=0.63). A Pittsburgh (PITT) bacteraemia score of ≥4 at presentation was associated with a mortality of 24% (four of 17 patients died) compared with 0 in 23 patients with PITT scores <4 (p=0.026). CONCLUSION: Medical therapy alone can be effective for RSIE when large vegetations are present. However a high sepsis score at presentation may increase risk of death. Larger studies are required to determine optimal indications for early surgical intervention.
BACKGROUND: Previously described prognostic markers in right-sided infective endocarditis (RSIE) include vegetation size ≥1cm, fever for more than three weeks, cardiac failure and severe sepsis. This study aimed to evaluate effectiveness of medical therapy for vegetations ≥1cm and explore determinants of outcome in a representative population of intravenous drug users (IDUs) at a metropolitan Australian health service. METHODS: Retrospective review of consecutive IDUs presenting to our institution with native-valve RSIE (by modified Duke criteria) over seven years (2005-2011). Data recorded included echocardiographic estimation of maximal vegetation diameter (classified as < or ≥1cm). Relationships between vegetation size and specified outcomes of death, septic shock, recurrence and relapse were examined by Chi-squared testing. RESULTS: Of 49 episodes five (10%) were managed surgically and a further four (8%) were lost to follow-up and excluded from the analysis. Of the remaining 40 evaluable medically treated patients (median age 28, range 20-55), 37 (93%) cultured methicillin-sensitive S. aureus and all had tricuspid valve involvement. Of 24 with vegetations ≥1cm, three died (mortality 13%) compared with one (6%) in 16 medically treated patients with vegetations <1cm (p=0.63). A Pittsburgh (PITT) bacteraemia score of ≥4 at presentation was associated with a mortality of 24% (four of 17 patients died) compared with 0 in 23 patients with PITT scores <4 (p=0.026). CONCLUSION: Medical therapy alone can be effective for RSIE when large vegetations are present. However a high sepsis score at presentation may increase risk of death. Larger studies are required to determine optimal indications for early surgical intervention.