Variables associated with diagnostic delay and mortality in infective endocarditis: an observational retrospective study

Background: In infective endocarditis (IE), a prompt diagnosis and therapy lead to better outcomes.Diagnostic delay seems common, but causing factors are still under-investigated, limiting actions to improve outcomes.This study examines variables associated with IE delayed diagnosis and mortality.Methods: This single-centre retrospective observational study included adults diagnosed with IE according to Duke's criteria from 2009 to 2022.IE diagnoses within 5 days from hospital admission (<5d) were compared to those from day 5 onwards (5d).Logistic regression and Cox analyses identified factors associated with 5d diagnosis and in-hospital mortality.Sensitivity analyses excluding recurrent endocarditis or diagnoses before 2016, and a post-hoc analysis focused on fever at admission were performed.Results: This study included 349 episodes of IE that occurred in 331 patients (females:31.2%;median age:72 years).Median time to diagnosis was 3 days (IQR:1-8), 196 (56.2%) patients received a diagnosis before and 153 (43.8%) after 5 days.Absence of fever at presentation was associated with 5d diagnosis (OR:2.09;]; p=0.011).Although mortality was not associated to a 5d diagnosis (HR:0.96;95%CI [0.49-1.87]p=0.905), a higher risk of mortality was found in patients with absence of fever (HR:2.03;95%CI [1.06-3.90];p=0.033) and embolic events (HR:2.15;]; p=0.023), which were more frequent in patients without fever (46/120, 38.3%) than with fever (54/227, 23.8%, p=0.007).Conclusions: IE patients presenting without fever have higher risk of delayed diagnosis and mortality, possibly due to a higher incidence of embolic events.In these patients, efforts to improve early diagnosis are required.