A Retrospective Review of the Natural Progression of Cardiac Vegetation

Introduction: Infective endocarditis (IE) is a life-threatening condition with an annual mortality of up to 40%. Vegetations are the hallmark of IE, however, factors that affect the initial size and changes in size remain unclear. Our study aims to investigate the natural history of cardiac vegetation, including changes in size and/or resolution with adequate treatment, and to analyze factors that influence size and potential for persistence. Material and methods: We conducted a retrospective review of 102 patients admitted with native-valve endocarditis at Henry Ford Health System from September 1, 2017, to June 30, 2019. We included patients treated with six weeks of intravenous antibiotics who had both a diagnostic and a follow-up echocardiogram after antibiotic completion. The primary outcome was the change in vegetation size. Secondary measures included pathogen identification, valve involvement, number of complications, associated IV drug use, and co-infection with hepatitis B/C. Results: Of the 102 patients reviewed, 30 patients matched the inclusion criteria. There was a significant decrease in vegetation size after adequate antibiotic treatment. However, complete resolution was not often seen. A statistically significant relationship was seen between vegetation size, IV drug use, and Staphylococcal species (including both methicillin-susceptible Staphylococcus aureus [MSSA] and methicillin-resistant S. aureus [MRSA]), whereas a history of hepatitis B or C was not significantly related to vegetation size. Conclusion: Large vegetation may predict a higher risk of embolic complications and can be reduced with IV antibiotics, although complete resolution is not likely. IV drug use and Staphylococcal endocarditis influence vegetation size and embolic complications. We argue that these subgroups should be prioritized for early surgical intervention.