Infective Endocarditis Trends in the US | Journal Scan

Study Questions:

Was the 2007 American College of Cardiology (ACC)/American Heart Association (AHA) change in infective endocarditis (IE) antibiotic prophylaxis guidelines temporally associated with different trends in IE incidence, microbiology, and outcome?


In a retrospective observational cohort study, the Healthcare Cost and Utilization Project – National Inpatient Sample (NIS) database (a large all-payer database including Medicare, Medicaid, private insurance, and uninsured patients) was used to investigate IE hospitalization rates in the United States from 2000-2011. The average annual rates of IE before and after the 2007 guideline change were compared using segmented regression analysis, as were microbiology and outcome (assessed as need for valve replacement).


There were 457,052 IE-related hospitalizations in the United States from 2000-2011, with a steady increase in incidence (p < 0.001). The trend in IE hospitalization rates from 2000-2007 (0.54 per 100,000 population [95% confidence interval, 0.32-0.75]) and 2008-2011 (0.6 per 100,000 population [95% confidence interval, 0.23-0.97]) was not statistically different (p = 0.74). The incidence in the number of Staphylococcus IE cases per 1 x 106 population during 2000-2007 and 2008-2011 were similar (p = 0.13), but Streptococcus IE hospitalization rates were significantly higher after the guideline revision (p = 0.002). Valve replacement rates for IE steadily increased over the interval 2000-2007 (p = 0.03), but showed a plateau from 2007-2011. Overall, there was no significant difference in the rates of valve replacement for IE before and after the guideline revision (p = 0.23).


The incidence of IE has increased in the United States over the last decade, with a significant increase in the incidence of Streptococcus IE following the 2007 IE prophylaxis guideline revision. The rates of hospitalization and of valve surgery due to IE did not change after the 2007 guideline revision.


It is hard to attribute the overall increase in incidence of IE to the 2007 guidelines when the rate of increase through 2007 was similar to after 2007. However, the incidence of Streptococcus-related IE changed relatively abruptly after the IE prophylaxis guideline revision in 2007, suggesting that a decreased use of antibiotic prophylaxis for dental procedures could have been responsible for the increased rate of Streptococcus IE. The degree of penetrance of the revised guideline recommendations into clinical practice remains an unknown variable. The authors appropriately propose ongoing monitoring of the impact of the guideline recommendations. In addition, in that neither past nor current guidelines on antibiotic are evidence-based, the decision of an informed patient might remain a good clinical option.

Clinical Topics: Cardiac Surgery, Congenital Heart Disease and Pediatric Cardiology, Invasive Cardiovascular Angiography and Intervention, Prevention, Cardiac Surgery and Arrhythmias, Cardiac Surgery and CHD and Pediatrics, Congenital Heart Disease, CHD and Pediatrics and Arrhythmias, CHD and Pediatrics and Interventions, CHD and Pediatrics and Quality Improvement, Interventions and Structural Heart Disease

Keywords: Anti-Bacterial Agents, Antibiotic Prophylaxis, Cardiac Surgical Procedures, Cohort Studies, Endocarditis, Bacterial, Endocarditis, Health Care Costs, Heart Defects, Congenital, Hospitalization, Incidence, Inpatients, Medicaid, Medicare, Medically Uninsured, Penetrance, Regression Analysis, Retrospective Studies, Secondary Prevention, Staphylococcus, Streptococcus

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