Importance of experience in transoesophageal echocardiographic evaluation of vegetation size in patients with infective endocarditis: a reliability study

Aims: Vegetation size assessed by transoesophageal echocardiography (TOE) is a decisive metric in guiding surgical intervention and prognosis in patients with definite infective endocarditis (IE). The aim of this study was to assess the impact of echocardiographic experience on the reliability and reproducibility of TOE measurements of vegetations in patients with IE.

Methods and results: Twenty-nine raters from a cardiac department at a tertiary centre were divided into three groups according to echocardiographic experience: experts, cardiologists, and novices. All raters were instructed to measure the maximum length of vegetations in 20 different TOE exams. Interrater agreement was evaluated using intraclass correlation coefficient (ICC), one-way analysis of variance, Kruskal-Wallis test, and Bland-Altmann plots. Reliability was assessed by minimal detectable change (MDC). All measurements were compared with the measured size agreed on by the multi-disciplinary IE team.There was an overall significant interrater variance between the three groups (P < 0.001). The variance was 10.1, 14.8, and 21.7 for the experts, cardiologists, and novices, respectively. ICC was excellent for experts (96.3%) and cardiologists (93.7%) and good for novices (84.6%). The three groups tended to measure smaller than the endocarditis team. MDC was 2.6 mm for experts, 3.3 mm for cardiologists, and 3.6 mm for novices.

Conclusion: The study showed good to excellent intraclass correlation but high dispersion in all groups. Variance decreased with higher experience. Our findings support current recommendations that complicated cases should be cared for by the multi-disciplinary endocarditis team and underline the importance of echocardiographic expertise when evaluating and measuring vegetations in patients with IE.