As with other IE cases, decisions concerning out- patient therapy may be considered and may be individualized on the basis of clinical impression of symptomatic recovery, cardiovascular stability, assessment of the family s ability to follow prescribed treatment, and availability of infrastructure for out- patient monitoring (Class IIb; Level of Evidence C). Prosthetic Material IE Staphylococcal endocarditis on a prosthetic cardiac valve or other cardiac prosthetic material is usually caused by coagulase-negative staphylococci that are methicillin resis- tant, especially if the endocarditis develops within 1 year after cardiac surgery.126 (See details in Table 7 for treat- ment of methicillin-resistant and methicillin-susceptible staphylococcal endocarditis based on consensus of the writing group and experience in the treatment of adult IE.) Additional recommendations for the treatment of staphylo- coccal endocarditis on intracardiac prosthetic material are listed in the AHA statement on Infective Endocarditis: Diagnosis, Antimicrobial Therapy, and Management of Eradication of infection involving pros- thetic material is considered difficult at best, even when prolonged optimal antibiotic treatment is used. Despite occasional reports of successful medical treatment, which requires long-term use of multiple antimicrobial agents, in most circumstances removal of the infected material is required to achieve a satisfactory outcome.127 The antibi- otic rifampin is included as an addition to other antibiotic drugs in the treatment of staphylococcal IE, especially when there is prosthetic material. Most staphylococcal strains are susceptible to rifampin, and in experimental systems, it has good tissue penetration. 