Prognostic implications of a negative echocardiography in patients with infective endocarditis

Background: Echocardiography plays an important role in infective endocarditis (IE) diagnosis according with the modified Duke criteria. We evaluated the implications of a positive echocardiography in the prognosis of a cohort of patients with IE. Methods: Prospective multicentre study in 31 Spanish centres. From January 2008 to September 2016, 3467 patients were included (2765 definite IE, 702 possible IE). The main outcome was in-hospital mortality. Echocardiography diagnosis was based on modified Duke criteria for the diagnosis of IE. Results: Median age was 69 years (interquartile range: 57-77 years). Comorbidity was high (mean Charlson index 4.7 +/- 2.8). Transoesophageal echocardiography was performed in 2680 (77.3%). The overall inhospital mortality rate was 26.7%. Univariate analysis showed that, in patients with definite IE, inhospital mortality was similar in patients with positive and negative echocardiography (27.7% vs. 24.6%, respectively, p = 0.121). In possible IE these figures were 27.5% vs. 16.7%, respectively, p < 0.001. Complications (cardiac and extra-cardiac [embolic, immunological, and septic shock]) were more frequent with positive than with negative echocardiography, regardless of clinical suspicion (definite IE 35.5% vs. 16.8%, respectively, p < 0.001; possible IE 20.8% vs. 7.6%, respectively, p < 0.001). Positive echocardiography was a predictor of inhospital death by logistic regression modelling, after adjusting for confounders, definite IE (odds ratio [OR] 1.3, 95% confidence interval [CI] 1.02-1.76, p = 0.036), possible IE (OR 1.59, 95% CI 1.02-2.45, p = 0.036). Conclusions: A positive echocardiography in patients with IE is associated with increased inhospital mortality, in addition to other clinical factors and comorbidities.