**5.1 Timing of surgery**

Only 5–16% of IDUs needs surgery [76–78]. However, if left-sided IE has clear indications for early surgery, and the indications for early surgery in right-sided IE are not established presently [79].

The strategy to delay surgery until the microbial therapy is accomplished and may decrease morbidity and mortality rates significantly. In keeping with published data, *early surgery* is a choice in case of IE with *Staphylococcus aureus* or fungal infection [1, 16, 80]. Early surgery of tricuspid valve IE is considered when associates (1) atrial septal defect; (2) prosthetic valve endocarditis; (3) infected pacing leads; (4) indwelling catheters; and (5) simultaneous left-sided IE [81, 82]. Additionally, development of bacteremia or pulmonary septic emboli also has early surgery.
