**15. Role of surgery**

Endocarditis caused by NVS is associated with high rates of complications including heart failure, embolization and valvular damage. The need for surgery and time of surgery remains to be determined. However based on outcomes of several cases published in the literature, the rate of surgical treatment is very high especially due to development of heart failure.

he rate of valve surgery is high; 51% (in a review of 29 cases of *Granulicatella* endocarditis by Adam et al.) [50], 48% (review of 23 cases of endocarditis caused by NVS by Guiliano et al.) [49], 38% (review of 30 cases of endocarditis caused by NVS by Stein et al.) [41], 44% (review of 9 cases of *A. defectiva* endocarditis by Hashimoto et al.) [75].

A vegetation size of 10 mm or more is associated with increased mortality and increased risk of embolic events [76]. EASE Trial showed that early surgery in infective endocarditis in patients with large vegetations significantly reduced the mortality, risk of systemic embolism or recurrence of infective endocarditis (3% in the early surgery group vs. 28% in the conventional treatment group) [77]. Lin et al. [68] reported 7 out of 8 cases of endocarditis caused by NVS had large vegetation sizes (10 mm). In the same review, 7 out of 8 cases required surgery (4 out of 8 cases required early valve replacement due to severe heart failure, while 3 cases underwent mitral valve repair 2,4, and 7 months after the diagnosis of endocarditis).

Combined approach with antibiotic treatment and surgery provides the best outcomes in endocarditis caused by NVS. Specifically, early surgical intervention should be considered for those patients with heart failure due to valvular destruction [68], hemodynamic compromise [49] or large vegetation sizes [68, 77].
