Prognostic value of residual vegetation after antibiotic treatment for infective endocarditis: A retrospective cohort study

Abstract

Infective endocarditis is associated with significant morbidity and mortality. Natural history of vegetations under antibiotic treatment is poorly understood, and the long-term prognostic impact of residual vegetations after complete treatment remains unknown. To evaluate prognostic impact of residual vegetation after complete and successful antibiotic treatment. In a retrospective cohort study, we included 134 patients hospitalized for infective endocarditis in a tertiary center, with presence of vegetation at diagnosis, treated with complete antibiotic therapy, from January 2013 to December 2017. The follow-up started at the end of antibiotic treatment, when healing was complete. Presence or absence of residual vegetation was assessed at this time. The primary endpoint was a composite of the occurrence of embolic event, recurrence of endocarditis or death from any cause. Eighty-five patients were men (63%), mean age was 69 ± 15-years-old and median follow-up was 16.3 (IQR: 5 to 30) months. Sixty-six (49%) patients have residual vegetations at the end of treatment. The primary endpoint occurred in 23 patients (35%) in the group with residual vegetation and in 16 patients (24%) without, which was not statistically relevant (OR 1.74; 95% confidence interval 0,82–3,67; P = 0.15). By univariate analysis, the occurrence of the primary endpoint was associated with an increasing size of vegetation under treatment (OR 5.94;95% CI 1.52–23.15; P = 0.01), or a size of vegetation over 10 mm at the end of treatment (OR 3.47;95% CI 1,19–10,08; P = 0.02); however, it was not corroborated by multivariate analysis. There was a trend of the antiplatelet therapy to be protective of the occurrence of the primary endpoint (0R = 0.30; 95% CI 0.09–0.99; P = 0.04) ( Table 1 , Fig. 1 ). Persistence of vegetation after healing is frequent but has no clear prognostic impact in patients treated for infective endocarditis.