Impact of time from symptom onset to diagnosis in infective endocarditis: insights from the nationwide NIDUS registry

Background Infective endocarditis (IE) often presents with non-specific symptoms, which may delay diagnosis and treatment. Previous studies exploring symptom duration have been limited by small cohorts or single-centre studies. We aimed to investigate patient characteristics, microbial aetiology, treatment, and all-cause mortality of patients with IE according to symptom duration prior to diagnosis. Methods We included all patients with first-time IE from the NatIonal Danish Endocarditis StUdies (NIDUS) registry (2016–2021). Patients with left-sided IE and available symptom duration were stratified as short, intermediate, or prolonged (≤ 7, 8–29, or ≥ 30 days). The primary outcome was six-month mortality. Results Among 2,938 patients with left-sided IE, median symptom duration was 8 days [IQR:4–20], and 17.6% had symptoms ≥ 30 days. The short-duration group compared with the prolonged-duration group was older (median 74.1 vs. 72.2 years), more often female (35.1% vs. 24.8%), had more comorbidities, embolism (14.5% vs. 8.9%), sepsis (28.2% vs. 12.2%), and Staphylococcus aureus IE (38.3% vs. 11.6%). The short- and intermediate-duration groups underwent surgery less frequently (18.1% and 23.2%) than the prolonged-duration group (31.7%). The six-month cumulative incidence of mortality was lower in the prolonged-duration group (21.8%) than in the short and intermediate groups (28.7% and 28.9%), although non-significant after adjustment (HR 0.92 [95% CI:0.74–1.14]) compared to the short group. Conclusion In patients with left-sided IE, short symptom duration prior to diagnosis was associated with Staphylococcus aureus IE, sepsis, and lower surgical rates. Prolonged symptom duration was associated with lower cumulative mortality, but this was not significant after multivariable adjustment.