Title: 0208 - Impact of the 2007 American Heart Association’s Antibiotic Prophylaxis Recommendations


Martin Thornhill (Presenter)
University of Sheffield

Teresa Gibson, Truven Health Analytics/IBM Watson Health, USA
Eli Cutler, Truven Health Analytics/IBM Watson Health, USA
Mark Dayer, Taunton and Somerset NHS Trust
Vivian Chu, Duke University Medical Center
Peter Lockhart, Carolinas Medical Center
Patrick O'Gara, Brigham and Women’s Hospital, and Harvard Medical School
Larry Baddour, Mayo Clinic College of Medicine


Objectives: The American Heart Association (AHA) updated its recommendations for antibiotic prophylaxis (AP) to prevent infective endocarditis (IE) in 2007, advising that AP cease for those at moderate-risk of IE, but continue for those at high-risk undergoing invasive dental procedures. Our objective was to study AP prescribing and IE incidence before and after the 2007 AHA recommendations in those at high-risk, moderate-risk and unknown/low-risk of IE in a large, representative US population.

Methods: High-risk, moderate-risk and unknown/low-risk individuals with linked prescription and Medicare or commercial healthcare data were identified in the Truven Health MarketScan databases from May 2003 through August 2015 (198,522,665 enrollee-years of data). AP prescribing and IE incidence were evaluated.

Results: Following the 2007 recommendation changes, there were 62.8% and 18.5% falls in AP prescribing for individuals at moderate- and high-risk of IE respectively. There was also a 1.7-fold increase in IE incidence (95%CI 1.0-2.9) among moderate-risk individuals (2.9 cases/month/100,000 increase) and a 2.8-fold increase (95%CI 1.7-4.6) in incidence among those at high-risk (51.3 cases/month/100,000 increase) compared to what would have been expected from extrapolation of the pre-2007 trend. There was no IE incidence increase in unknown/low-risk individuals, despite a 52.2% fall in AP prescribing.

Conclusions: AP prescribing decreased in all IE at-risk groups. This reduction was larger for individuals at moderate or low/unknown-risk than that for those at high-risk. These decreases were associated with an increase in IE incidence among high-risk individuals, a trend towards an increase in IE incidence for moderate-risk patients and no change for those at low/unknown-risk. Although these data do not prove a cause-effect relationship between reduction of AP administration and increase in IE incidence, they provide unique new evidence to help those with responsibility for drafting recommendations on the management of individuals at increased risk of IE who are undergoing invasive dental procedures.

This abstract is based on research that was funded entirely or partially by an outside source:
This study was funded by a research grant from Delta Dental of Michigan and its Research and Data Institute.

Disclosure Statement:
The submitter must disclose the names of the organizations with which any author have a relationship, the nature of the relationship, and the clinical or research area involved. The following is submitted: This study was funded by a research grant from Delta Dental of Michigan and its Research and Data Institute.