Author + information
- Sadip Pant, MD∗ (, )
- Samir Patel, MD,
- Nileshkumar Patel, MD,
- Abhishek Deshmukh, MD and
- Jawahar L. Mehta, MD, PhD
- ↵∗Cardiovascular Medicine, University of Louisville, Department of Cardiovascular Medicine, 526 S Jackson Street, Louisville, Kentucky 40202
We read with great interest the letter by Drs. Kazi and Bolger on our study “Trends in Infective Endocarditis Incidence, Microbiology, and Valve Replacement in the United States From 2000 to 2011” (1). We agree with Drs. Kazi and Bolger that any intervention in the field of medicine gets adopted in practice gradually after the publication of a “practice changing guideline” or late-breaking clinical trial. However, in this era of information technology, most physicians (at least in the United States) have ready access to journals and tend to update themselves swiftly. Moreover, publications often make it to journals in e-format ahead of print (for instance, the American College of Cardiology/American Heart Association guideline was e-published in April 2007, but appeared in print in October 2007). Hence, we believe it is reasonable to use this year as a start of practice change as opposed to hypothetical cut off (beginning of 2008) proposed by Drs. Kazi and Bolger. However, as we mentioned in our limitation section, we did not study the antibiotic prescription data to precisely answer the concerns by Drs. Kazi and Bolger.
Further, we compared the annual rates of hospitalizations for infective endocarditis (IE) before and after the introduction of the 2007 IE antibiotic prophylaxis guidelines using segmented regression analysis of the interrupted time series. The linear model is a good fit based on adjusted R2 value for the model (adjusted R2 = 0.87 for IE hospitalization trend). This method has been used in IE trends study in the past as well (2). Furthermore, as evident in Table 1 in our paper (1), the rate of Streptococcus IE-related hospitalization increased significantly over the study period (2000 to 2011). As we discussed in our study, change in antibiotic prophylaxis is a speculation. Other possibilities include increase in enterococcus IE subset, and increasing survival of IE risk-prone populations, such as adults with congenital heart disease and device implants. In the absence of prospective randomized data, the differing results from alternative breakpoint in segmented regression as done by Drs. Kazi and Bolger does not refute our hypothesis, but further echoes the need for ongoing monitoring of the impact of new guidelines. Finally, observations made from administrative database should be considered “hypothesis generating” and not decisive. Rigorous prospective data is needed before drawing conclusions by Drs. Kazi and Bolger that “restricted use of antibiotic for IE prophylaxis appears to have had no measurable adverse impact on the health of the American public.”
Please note: The authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- American College of Cardiology Foundation