Predictors of long-term mortality in left-sided infective endocarditis: an historical cohort study in 414 patients

Introduction:: Very limited data are available on the long-term outcome of infective endocarditis (IE) and its determinants. The aim of this study was to identify the predictors of long-term mortality in patients affected by left sided IE (LSIE). Methods:: This was an historical retrospective observational study on prospectively collected data from patients with LSIE hospitalized in our Unit (January 2000-December 2017). Multiple variables relevant to history, physical examination, laboratory tests, echocardiography, comorbidities, complications and outcome were analysed by Cox regression to identify predictors of long-term mortality. Results:: 414 patients were included, and followed up for a median of 39 months [IQR 11-74]. Median age was 59 years [range 3-89], and most patients were male. Over 50% showed at least one comorbidity. Hyperglycaemia, increased creatinine and an indication for surgery predicted in-hospital mortality, while a prior myocardial infarction, chronic kidney disease (CKD) on hemodialysis and a larger vegetation were independent predictors of 1-year mortality. At multivariate analysis, peripheral arterial disease (p= 0.017), hyperglycemia on admission (p=0.013) and a higher BMI (p=0.009) were independent predictors of long-term mortality in 1-year survivors. At multivariable Cox proportional hazard regression, peripheral arterial disease (p=0.002), hyperglycemia (p=0.041) and CKD on hemodialysis (p=0.025) confirmed to be independently associated with an increased risk of long-term mortality in the overall 414 patient cohort. Conclusions:: Cardiovascular and metabolic risk signals, specifically peripheral arterial disease and hyperglicemia, affect long-term mortality of LSIE. An active and long-term follow up seems warranted in IE survivors showing these conditions at outset.