Endocarditis: Hospitalizations and Mortality Trends

Behnood Bikdeli, MD Yale/YNHH Center for Outcomes Research and Evaluation One Church St, Suite 200 New Haven CT 0651MedicalResearch.com Interview with:
Behnood Bikdeli, MD
Yale/YNHH Center for Outcomes Research and Evaluation
One Church St, Suite 200
New Haven CT 0651

MedicalResearch.com: What are the main findings of the study?

Dr. Bikdeli: We determined the trends in hospitalizations and mortality from endocarditis among US older adults from 1999 to 2010. Endocarditis is the most serious cardiovascular infection and our study that had a very large sample, signified the high burden of endocarditis in this time period.

Further, as a secondary question, we compared the trends in hospitalizations and outcomes before versus after 2007, a year in which the American Heart Association (AHA) made a very radical change in its recommendations. The 2007 AHA recommendations narrowed the indications for use of antibiotics to prevent endocarditis. Many people were concerned that after such recommendations, the rates of endocarditis might increase remarkably. Our study did not show a consistent increase in hospitalizations or outcomes after 2007. What is unique about our study is that we demonstrated these trends to be consistent after adjustments for demographic changes over time. Moreover, we demonstrated that the adjusted mortality rates did not show a consistent increase after 2007, when the AHA guidelines recommended restricted antibiotic prophylaxis for endocarditis.

MedicalResearch.com: Were any of the findings unexpected?

Dr. Bikdeli: Yes, in fact we observed a consistent decline in endocarditis hospitalization rates from 2006-2010. This interesting finding warrants further investigation. One possible explanation could the concerted efforts that have been used for reducing the rates of catheter-associated bloodstream infections.

Another surprising finding was the consistently higher rates of endocarditis and worse outcomes for black patients. This issue also requires more in-depth research. 

MedicalResearch.com: What should clinicians and patients take away from your report?

Dr. Bikdeli: This is a very important question. We caution against under or over interpretations from our findings. First, as I said earlier, our study shows that the burden of endocarditis among elderly Medicare beneficiaries is very high, with a third of patients dying one year from diagnosis.

Second, we did not observe a consistent increase in hospitalization rates after 2007, when the AHA recommended for restrictive use of antibiotic prophylaxis. Our investigation was not a comparative effectiveness study to prove the non-inferiority of restrictive prophylaxis. However, the trends that we observed, as well as a few studies from the US, UK, and France, do not show a change in pattern of endocarditis hospitalizations after recommendations for restrictive antibiotic use.

Clinicians should consider the risks and benefits of prophylaxis on a case-by-case basis and should share the information with their patients for appropriate decision making. My personal opinion is that widespread antibiotic prophylaxis would not have a big beneficial impact, and is not free from adverse effects. Nevertheless, there may be several instances in which antibiotic prophylaxis for endocarditis is reasonable.

MedicalResearch.com: What recommendations do you have for future research as a result of this study?

Dr. Bikdeli: With regard to antibiotic prophylaxis for endocarditis, one would ideally want to see comparative effectiveness studies (e.g. randomized controlled trials). However, widespread antibiotic prophylaxis, most probably, has a small effect size. Therefore, a randomized trial to test its efficacy might require around 50,000 patients, make it extremely unlikely to happen in near future. What I expect to be helpful is continued surveillance investigations, similar to our study. Also, we certainly need to further investigate better therapeutic options for management of endocarditis, and would also need to address the disparities for high-risk subgroups, such as blacks.


Trends in Hospitalization Rates and Outcomes of Endocarditis among Medicare Beneficiaries
Behnood Bikdeli, MD; Yun Wang, PhD; Nancy Kim, MD, PhD; Mayur M. Desai, PhD, MPH; Vincent Quagliarello, MD; Harlan M. Krumholz, MD, SM

J Am Coll Cardiol. 2013;():. doi:10.1016/j.jacc.2013.07.071


Last Updated on November 3, 2014 by Marie Benz MD FAAD