Cost-effectiveness of infective endocarditis prophylaxis for mitral valve prolapse with or without a mitral regurgitant murmur.

To assess the cost-effectiveness of prevention of infective endocarditis (IE) and to calculate cost-effectiveness of currently recommended regimens in patients with mitral valve prolapse (MVP), data on risk of death, complications, and health-care use, and cumulative incremental health-care costs due to the occurrence of IE were combined with data on the prevalence and manifestations of MVP, estimated years of life lost, and efficacy of antibiotic prophylaxis. Effectiveness and costs of standard endocarditis prophylaxis regimens were calculated per IE case prevented and years of life saved. Under the most likely scenario, oral amoxicillin prophylaxis for all MVP patients would prevent 32 cases of IE per million dental procedures at approximate costs of $119,000 per prevented case and $21,000 per year of life saved. Limiting prophylaxis to patients with mitral murmurs would prevent 80 cases of IE per million procedures at costs of about $19,000 per prevented case and $3,000 per year of life saved. Erythromycin prophylaxis was slightly less expensive than amoxicillin per benefit because of lower cost and lack of drug anaphylaxis, whereas intravenous ampicillin was 7 to 30 times more costly. Sensitivity analyses suggested that erythromycin prophylaxis might be cost-saving under some scenarios, whereas intravenous ampicillin use might cause net loss of life. Thus, prevention with oral antibiotics of the cumulative morbidity and incremental health care costs due to IE in MVP patients is reasonably cost-effective for MVP patients with mitral murmurs.