Patients with relapsing or recurrent IE are at greater risk of congestive heart failure and increased need for cardiac valve replacement surgery, and they have a higher mortality rate than patients with a first episode of native valve IE.118 124 Additionally, patients with multiple episodes of native or prosthetic valve IE are at greater risk of additional episodes of endocarditis, each of which is associated with the risk of more Published series regarding endocarditis in patients with CHD are underpowered to determine the extent to which a specific form of CHD is an independent risk factor for morbidity and mortality. Nevertheless, most retrospective case series suggest that patients with complex cyanotic heart disease and those who have postoperative palliative shunts, conduits, or other prostheses have a high lifetime risk of acquiring IE, and these same groups appear at highest risk for morbidity and mortality among all patients with CHD.125 129 In addition, multiple series and reviews reported that the presence of prosthetic material130,131 and complex cyanotic heart disease in patients of very young age (newborns and infants 2 years of age)132,133 are 2 factors associated with the worst prognoses from IE. Some types of CHD may be repaired completely without residual cardiac defects. As shown in Table 3, the Committee concludes that prophylaxis is reasonable for dental procedures for these patients during the first 6 months after the procedure. In these patients, endothelialization of prosthetic material or devices occurs within 6 months after the procedure.134 The Committee does not recommend prophylaxis for dental procedures more than 6 months after the procedure provided that there is no residual defect from the repair. In most instances, treatment of patients who have infected prosthetic materials requires surgical removal in addition to medical therapy with associated high morbidity and mortality rates. 