There should be a shift in emphasis away from a focus on a dental procedure and antibiotic prophylaxis toward a greater emphasis on improved access to dental care and oral health in patients with underlying cardiac conditions associated with the highest risk of adverse out- come from IE and those conditions that predispose to the acquisition of IE. Cardiac Conditions and Endocarditis Previous AHA guidelines categorized underlying cardiac conditions associated with the risk of IE as those with high risk, moderate risk, and negligible risk and recommended prophylaxis for patients in the high- and moderate-risk categories.1 For the present guidelines on prevention of IE, the Committee considered 3 distinct issues: (1) What under- lying cardiac conditions over a lifetime have the highest predisposition to the acquisition of endocarditis? (2) What underlying cardiac conditions are associated with the highest risk of adverse outcome from endocarditis? (3) Should recommendations for IE prophylaxis be based on either or both of these 2 conditions? Underlying Conditions Over a Lifetime That Have the Highest Predisposition to the Acquisition of Endocarditis In Olmsted County, Minnesota, the incidence of IE in adults incidence has remained stable during the past 4 decades and is similar to that reported in other studies.100 103 Previously, RHD was the most common underlying condition predispos- ing to endocarditis, and RHD is still common in developing countries.99 In developed countries, the frequency of RHD has declined, and MVP is now the most common underlying condition in patients with endocarditis.104 Few published data quantitate the lifetime risk of acquisi- tion of IE associated with a specific underlying cardiac condition. 