The effects of cardiopulmonary bypass and compromised renal function on antibiotic concentra- tions in serum should be considered and dosages adjusted as necessary before and during the procedure. Other Considerations There is no evidence that coronary artery bypass graft surgery is associated with a long-term risk for infection. Therefore, antibi- otic prophylaxis for dental procedures is not needed for individ- uals who have undergone this surgery. Antibiotic prophylaxis for dental procedures is not recommended for patients with coronary artery stents (Class III, LOE C). The treatment and prevention of infection for these and other endovascular grafts and prosthetic devices are addressed in a separate AHA publi- cation.152 There are insufficient data to support specific recom- mendations for patients who have undergone heart transplanta- tion. Such patients are at risk of acquired valvular dysfunction, especially during episodes of rejection. Endocarditis that occurs in a heart transplant patient is associated with a high risk of adverse outcome (Table 3).153 Accordingly, the use of IE prophylaxis for dental procedures in cardiac transplant recipients who develop cardiac valvulopathy is reasonable, but the useful- ness is not well established (Class IIa, LOE C; Table 4). The use of prophylactic antibiotics to prevent infection of joint prosthe- ses during potentially bacteremia-inducing procedures is not within the scope of this document. Future Considerations Prospective placebo-controlled, double-blinded studies of anti- biotic prophylaxis of IE in patients who undergo a bacteremia- producing procedure would be necessary to evaluate accurately the efficacy of IE prophylaxis. Additional prospective case- control studies are needed. The AHA has made substantial revisions to previously published guidelines on IE prophylaxis. Given our current recommendations, we anticipate that signifi- cantly fewer patients will receive IE prophylaxis for a dental procedure. Studies are necessary to monitor the effects, if any, of these recommended changes in IE prophylaxis. 