The relationship between causative microorganisms and cardiac lesions caused by infective endocarditis: New perspectives from the contemporary cohort of patients

•None of the infective endocarditis (IE) cardiac lesions is microorganism specific.•More severe lesions are caused by Staphylococcus aureus, coagulase-negative staphylococci, and non-HACEK bacteria.•The highest tendency to form multiple lesions have non-HACEK group.•Multiple IE cardiac lesions are linked to higher propensity for surgery.•The Echo IE Sum can be useful in therapeutic decision-making. The etiology of infective endocarditis (IE) is changing. More aggressive forms with multiple IE cardiac lesions have become more frequent. This study sought to explore the relationship between contemporary causative microorganisms and IE cardiac lesions and to analyze the impact of multiple lesions on treatment choice. In 246 patients hospitalized for IE between 2008 and 2015, cardiac lesions caused by IE were analyzed by echocardiography, classified according to the 2015 European Society of Cardiology guidelines and correlated with microbiological data. We defined a new parameter, the Echo IE Sum, to summarize all IE cardiac lesions in a single patient, enabling comprehensive comparisons between different etiologies and treatment strategies. Staphylococcus aureus was associated with the development of large vegetation (OR 2.442; 95% CI 1.220–4.889; p=0.012), non-HACEK bacteria with large vegetation (OR 13.662; 95% CI 2.801–66.639; p=0.001), perivalvular abscess or perivalvular pseudoaneurysm (OR 5.283; 95% CI 1.069–26.096; p=0.041), and coagulase-negative staphylococci (CoNS) with leaflet abscess or aneurysm (OR 3.451; 95% CI 1.285–9.266, p=0.014), and perivalvular abscess or perivalvular pseudoaneurysm (OR 4.290; 95% CI 1.583–11.627; p=0.004). The Echo IE Sum significantly differed between different etiologies (p