Clinical Practice of Surgical Treatment for Left-Sided Infective Endocarditis: Nationwide Data from the NIDUS Registry

BACKGROUND: Surgery is an essential treatment for selected patients with infective endocarditis (IE). Despite indications for surgery, not all patients undergo surgery. Most previous IE cohorts have examined a selected group of patients from primary tertiary centers. Thus, the aims of this study were to describe the use of surgery by indication and to assess mortality in a nationwide cohort of patients with left-sided IE. METHODS: This study was an observational cohort study including patients with left-sided IE from the National Danish Endocarditis Studies (2016-2021). Patients were categorized according to the presence of surgical indications defined as a Class I indication for surgery according to the 2015 European guidelines or a vegetation ≥10 mm on the diagnostic echocardiography and whether surgery was performed. One-year mortality was assessed with the 1-Kaplan-Meier estimator and multivariable Cox regression models. RESULTS: Among 3017 patients, 662 (21.9%; median age, 66.9 years) underwent surgery, 655 (21.6%; median age, 75.9 years) had surgical indications but received conservative treatment, and 1700 (56.5%; median age, 76.0 years) had no surgical indications. Surgical patients had fewer comorbidities and more streptococci, whereas nonsurgical patients had more comorbidities and Staphylococcus aureus . Patients with surgical indications who did not undergo surgery had the highest in-hospital (31.8% versus 12.5% versus 15.7%; P <0.001) and 1-year (50.5% versus 17.0% versus 33.5%, P <0.001) mortality compared with surgical patients and those without indications. Multivariable Cox models confirmed these findings. High surgical risk (22.8%) was the most reported reason for withholding surgery. CONCLUSIONS: In a nationwide consecutive cohort of patients with left-sided IE, 40% had indications for surgery according to guidelines, but only half of these underwent surgery. Surgically treated patients had the highest survival but were a decade younger, had fewer comorbidities, and had less frequent IE caused by S aureus. Thus, confounding by indication remains a limitation, and more studies are warranted to explore the management of patients at high surgical risk.