Infective Endocarditis Hospitalizations Before and After the 2007 American Heart Association Prophylaxis Guidelines

Background: In 2007, the American Heart Association (AHA) published revised guidelines for infective endocarditis (IE) prophylaxis. Population-based data with respect to the potential impact of these revised guidelines are lacking. Methods: The Canadian Institute for Health Information Discharge Abstract Database was used to identify all hospitalizations between April 2002 and March 2013 having IE as a primary diagnosis. Hospitalization rates were determined using age-specific population data from Statistics Canada. Interrupted time series analysis was used to evaluate changes in the slope of hospitalization rates after the AHA guidelines were published. Results: There were 9431 hospitalizations during the study period among 8055 patients (63% male patients). Time trend analysis showed an increase of 0.05 IE hospitalizations per 10 million population per month (95% confidence interval, 0.005-0.09; P = 0.029) from April 2002-March 2007 and an increase of 0.07 IE hospitalizations per 10 million population per month from April 2007-March 2013 (interaction P = 0.5213). Change-point analysis showed that a change in the slope occurred in April 2011, 4 years after publication of the revised AHA guidelines. Staphylococcus aureus was the most commonly reported organism (29.4%). Streptococcal infections decreased over time, beginning before the 2007 guidelines (P < 0.0001). The presence of a pacemaker or defibrillator was an increasingly prevalent risk factor over time (4% increase per year; P = 0.0178). Conclusions: The rate of IE hospitalizations increased in Canada before and after the publication of the 2007 AHA guidelines, with no significant change in slope after 2007. These guidelines had no impact on the incidence of IE hospitalizations.