A quantitative assessment of pre-dental antibiotic prophylaxis for patients with mitral-valve prolapse.

Because antibiotic prophylaxis for dental procedures in patients with mitral-valve prolapse (MVP) has been controversial, we performed a decision analysis to assess the costs and effects of the oral and parenteral penicillin regimens currently recommended for patients at high risk for bacterial endocarditis. The analysis suggests that there is a very small risk of post-dental endocarditis in MVP (4.1 cases per 10(6) procedures) which is outweighed by a greater risk of fatal reactions to parenteral penicillin (15 deaths per 10(6) courses). Parenteral penicillin prophylaxis therefore causes a net loss of life. For oral penicillin the risk of a fatal reaction is lower (0.9 deaths per 10(6) courses). However, oral penicillin prophylaxis appears to spare life only in older adults with MVP and at an extremely high cost: Over +1 million must be spent to spare one year of life. Personal preferences may still make antibiotic prophylaxis desirable for individual MVP patients. However, from a societal perspective, routine predental antibiotic prophylaxis for MVP is a very expensive preventive strategy.