Tricuspid valve endocarditis due to Staphylococcus aureus. Correlation of two-dimensional echocardiography with clinical outcome.

We studied 53 episodes (51 patients) of tricuspid valvular endocarditis caused by Staphylococcus aureus in a predominantly addicted population and correlated two-dimensional echocardiographic findings with clinical outcome. Thirty-eight episodes with (vs 15 episodes without) tricuspid vegetations on the two-dimensional echocardiogram were significantly associated with (1) longer duration of fever on therapy (mean of 12.3 days vs 6.8 days, respectively; p less than 0.005); and (2) higher frequency of increased right ventricular end-diastolic (RVED) dimension (25 of 38 cases [66 percent] vs two of 15 cases [13 percent], respectively; p less than 0.01). Only patients with increased RVED dimension (5/25; 20 percent) required tricuspid valvular surgery for prolonged fever or progressive right-sided heart failure (p less than 0.05 vs patients with normal RVED dimension). Tricuspid vegetations greater than 1.0 cm identified a subset of patients at increased risk for developing clinical right-sided heart failure during the active or convalescent phase of endocarditis (p less than 0.02 vs patients with tricuspid vegetations less than 1.0 cm). An unexpectedly high prevalence of asymptomatic prolapse of the mitral valve was observed in this population (23 of 53 episodes; 43 percent). Detection of tricuspid vegetations in patients with endocarditis due to S aureus is not a primary indication for early surgery, but identifies patients more likely to exhibit short-term and long-term complications of their infection.