Temporal Trends in Infective Endocarditis in the Context of Prophylaxis Guideline Modifications: Three Successive Population-Based Surveys
What are the temporal trends, incidence, and clinical characteristics in infective endocarditis (IE) following the 2002 French IE prophylaxis guideline modifications?
Three 1-year population-based surveys were conducted in 1991, 1999, and 2008 in three French regions, totaling 11 million inhabitants ages ≥20 years. The authors prospectively collected IE cases from all medical centers and analyzed age- and sex-standardized IE annual incidence trends.
Overall, 993 expert-validated IE cases were analyzed (323 in 1991; 331 in 1999; and 339 in 2008). IE incidence remained stable over time (95% confidence intervals given in parentheses): 35 (31-39), 33 (30-37), and 32 (28-35) cases per million in 1991, 1999, and 2008, respectively. Oral streptococci IE incidence did not increase either in the whole patient population (8.1 [6.4-10.1], 6.3 [4.8-8.1], and 6.3 [4.9-8.0] in 1991, 1999, and 2008, respectively) or in patients with pre-existing native valve disease. The increased incidence of Staphylococcus aureus IE (5.2 [3.9-6.8], 6.8 [5.3-8.6], and 8.2 [6.6-10.2]) was not significant in the whole patient population (p = 0.23), but was significant in the subgroup of patients without previously known native valve disease (1.6 [0.9-2.7], 3.7 [2.6-5.1], and 4.1 [3.0-5.6]; p = 0.012).
Scaling down antibiotic prophylaxis indications was not associated with an increased incidence of oral streptococcal IE. A focus on avoidance of S. aureus bacteremia in all patients, including those with no previously known valve disease, will be required to improve IE prevention.
The precise incidence of IE is difficult to determine due to the relative rarity of the disease and variability of diagnosis and reporting. As much as methods could be expected to remain unchanged between three discrete surveys spanning 18 years, this study makes the important observation that IE rates did not appear to increase in these regions of France despite revised IE prophylaxis guidelines that were proposed there in 2002. Based on that, it might be reasonable to conclude that a dramatic decrease in the use of IE prophylaxis has not resulted in an increase in IE occurrence––but only if the new guidelines were broadly adopted (which has not been the case in the United States). The study offers an important piece of data, but it may never be possible to prove equivalent efficacy of the revised guidelines. In the interim, patient education (about valve disease, about IE, about oral hygiene, and about available options for prophylaxis) seems both reasonable and ethical.
Keywords: Endocarditis, Staphylococcal Infections, Staphylococcus aureus, Antibiotic Prophylaxis
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