The incidence of infective endocarditis has increased steadily in the United States from 2000 to 2011, according to recent data published in the Journal of the American College of Cardiology.
The trend in rising incidence corresponds with a 2007 guideline update from the American College of Cardiology and American Heart Association that restricted the use of antibiotic prophylaxis to high-risk patients.
“The increase in the incidence of infective endocarditis is likely related to an increase in the population at risk, such as older, diabetic and hemodialysis patients, prosthetic device recipients and patients who undergo a number of invasive procedures,” Nileshkumar Patel, MD, from the department of internal medicine at Staten Island University Hospital, New York, and Sadip Pant, MD, from the department of cardiovascular medicine at the University of Louisville, Kentucky, told Cardiology Today.
Pant, Patel and colleagues conducted a retrospective, observational, cohort study to compare the incidence of infective endocarditis before and after the guideline update from 2000-2007 to 2008-2011. The researchers also observed national trends in the microbiology of infective endocarditis and valve replacement rates. Information was culled from the Nationwide Inpatient Sample database.
More than 457,000 hospitalizations related to infective endocarditis occurred during the study period, with a steady increase in incidence from 2000 to 2011 (P < .001), according to the data.
The rate of infective endocarditis-related hospitalizations changed from 0.54 per 100,000 people in 2000-2007 to 0.6 per 100,000 people in 2008-2011.
Analysis of the microbiology showed an increase in all pathogen types (P < .001), including cases of infective endocarditis due to Staphylococcus, which increased from 33% in 2000 to 40% in 2011; Streptococcus, which increased from 24.8% to 27%; gram-negative bacteria, which increased from 5.3% to 8.2%; and fungi, which increased from 0.6% to 1.4% (P < .001 for all). Hospitalization rates due to Streptococcus infective endocarditis were higher after the release of the new guidelines in 2007 (P = .002).
“We can’t say for sure that an increase in Streptococcal infective endocarditis was because of a change in guidelines,” Patel and Pant told Cardiology Today. “However, our study raises important questions about the impact of the ACC/AHA guidelines and underlines the need for ongoing monitoring of both antibiotic prophylaxis prescribing practices and the incidence of infective endocarditis.”
The researchers also observed a fixed increase in rates of valve replacement from 2000 to 2007 (P = .03), but rates stabilized after the guideline revision. Overall, there was no significant difference in rates of valve replacement for infective endocarditis before and after the guideline update, according to the results.
“Since we did not study the antibiotic prescription pattern before and after the change in guidelines, we can only speculate but cannot prove from our study whether the association is the result of restricted antibiotic utilization,” Pant and Patel said. “On the same note, a recent study from the United Kingdom showed an increase in infective endocarditis cases with a decrease in antibiotic use after the National Institute for Health and Care Excellence (NICE) guideline change in 2008. We, therefore, suggest that there is a need for ongoing monitoring of the guideline and their impact on the disease incidence.” – by Stephanie Viguers
For more information:
Nileshkumar Patel, MD, can be reached at the University of Miami Miller School of Medicine, 1611 Northwest 12th Avenue, Miami, FL 33136.
Disclosure: Pant and Patel report no relevant financial disclosures.