699 - A Retrospective Review of the Progression of Cardiac Vegetations with treatment

Background: The purpose of our study was to assess the natural history of cardiac vegetations in native valves( NVIE) including changes in size and/or resolution with adequate treatment, as well as analyze factors that influence initial size.

Methods: We did a  retrospective review of 102  patients discharged  with a diagnosis NVIE at a community hospital.  These patients were then screened to see if they received an adequate course of antimicrobial therapy and had follow up echocardiograms. The primary outcome measured was the change in vegetation size. We also assessed  secondary measures including pathogen identified, the valve involved, complications, and associated IDU and any co-infections.

Results:
31 patients fulfilled the study criteria and showed an initial mean vegetation size of 170mm upon initial echocardiography. The follow-up size after antibiotic treatment was 78mm suggesting a statistically significant relationship between antibiotic completion and reduction in vegetation size . (p-value 0.005). 
T-Test was used for subgroup analysis and showed that  the initial size of vegetations was significantly larger in IDUs (311) when compared to non-IDU (92)(p-value= 0.026).Patients who had embolic phenomena had significantly larger initial vegetations than those with no embolic complication. 
Initial vegetation size was significantly larger for people with embolic complications (308 mm vs 82.65 mm, p-value 0.013).We also found that patients with Staphylococcal endocarditis had larger vegetations than those with non-staphylococcal endocarditis (264 vs 39, p-value  0.001). and treatment led to a larger decrease in vegetation size (152 vs 7, p value 0.007)

Conclusion: Our small study suggests that successful treatment of NVIE does lead to a decrease in vegetation size though resolution of the vegetation does not occur. We also found that embolic phenomenon tended to occur with larger vegetations with our study suggesting that a vegetation > 3 cm was more likely to embolize. Our study also shows that vegetations in NVIE in injection drug users were larger than those in non-IDU and vegetation size is larger in patients with staphylococcal endocarditis however successful treatment in these patients also leads to a larger decrease in size of these vegetations