BACKGROUND: In 2009, updated European Society of Cardiology guidelines on the prevention, diagnosis, and treatment of infective endocarditis (IE) were released and restricted the use of antibiotic prophylaxis to high-risk patients only. The aim of this study was to analyze the effect of the restrictive antibiotic regimen on the incidence and manifestations of surgically treated IE before and after the guideline change.

METHODS: This study retrospectively analyzed data of 4917 patients who underwent valve surgical procedures for IE between 1994 and 2018 in 6 German cardiac surgery centers. Potential risk factors for 30-day mortality were assessed using logistic regression. Interrupted time series regression was used to evaluate the effect of the guideline change on the manifestation of IE.

RESULTS: A total of 2014 patients (41%) underwent surgical procedures before the guideline change, and 2903 patients (59%) underwent surgical procedures after the change. After 2009, patients were older (67.0 years [interquartile range, 56.0-74.0 years] vs 64.0 years [interquartile range, 52.0-71.0 years]; P < .001), and they presented with more comorbidities, such as hypertension (56.9% vs 41.7%; P < .001), diabetes (27.4% vs 24.4%; P = .020), peripheral artery disease (8.5% vs 6.5%; P = .011), and preoperative acute kidney injury (42.8% vs 31.9%; P < .001). Patients had worse clinical outcomes with respect to 30-day mortality (18.1% vs 14.3%; P = .001) and 1-year mortality (37.1% vs 29.1%; P < .001). An increase in Streptococcus-related IE (P = .002) and an increase in mitral valve IE (P = .035) were observed after the guideline change.

CONCLUSIONS: Since 2009, there has been a significant increase in the incidence of mitral valve IE and Streptococcus-related IE. Patients undergoing surgical procedures for IE present with more comorbidities, which contribute to high mortality rates.