A 10-year retrospective study of infective endocarditis at a university hospital with special regard to the timing of surgical evaluation in S-viridans endocarditis

A total of 154 episodes of infective endocarditis (IE) in 149 patients were studied retrospectively with special regard to the major aetiological grou ps and the surgical evaluation. There mere 136 episodes of native valve end ocarditis (NVE) (88%) and 18 episodes of prosthetic valve endocarditis (PVE ) (12%). Three major groups of NVE crystallized: Streptococcus viridans in 37 (27%), Staphylococcus aureus in 39 (29%) and culture negative IE in 28 ( 21%) episodes. In these groups surgery during the active phase was required in 41, 28 and 18%, respectively, At the operation myocardial abscess was f ound in as many as 7/15 cases with S. viridans, but in only in 3/11 cases w ith S, aureus and 1/5 cases with culture negative IE. The mean duration of preoperative antibiotic treatment was 34 d. This long period of unsuccessfu l pharmacotherapy, preceded by a mean of 47 d from start of symptoms to adm ission to hospital, has probably resulted in the high frequency of myocardi al abscess in S, viridans NVE. Surgical evaluation should be considered whe n fever persists beyond 10 d of adequate treatment, even in the absence of clinically apparent complications, Among the PVE episodes, 11/18 were manag ed with pharmacological treatment alone. Uncomplicated PVE may thus often b e successfully treated with antibiotics alone.