Asymptomatic and symptomatic embolic events in infective endocarditis: associated factors and clinical impact

Background: Embolic complications of infective endocarditis are common. The impact of asymptomatic embolism is uncertain.

Objectives: To determine the frequency of emboli due to IE and to identify events associated with embolism.

Methods: Retrospective analysis of an endocarditis database, prospectively implemented, with a post hoc study driven by analysis of data on embolic events. Data was obtained from the International Collaboration Endocarditis case report forms and additional information on embolic events and imaging reports were obtained from the medical records. Variables associated with embolism were analyzed by the statistical software R version 3.1.0.

Results: In the study period, 2006-2011, 136 episodes of definite infective endocarditis were included. The most common complication was heart failure (55.1%), followed by embolism (50%). Among the 100 medical records analyzed for emboli in left-sided infective endocarditis, 36 (36%) were found to have had asymptomatic events, 11 (11%) to the central nervous system and 28 (28%) to the spleen. Cardiac surgery was performed in 98/136 (72%). In the multivariate analysis, splenomegaly was the only associated factor for embolism to any site (p<0.01, OR 4.7, 95% CI 2.04-11). Factors associated with embolism to the spleen were positive blood cultures (p=0.05, OR 8.9, 95% CI 1.45-177) and splenomegaly (p<0.01, OR 9.28, 95% CI 3.32-29); those associated to the central nervous system were infective endocarditis of the mitral valve (p<0.05, OR 3.5, 95% CI 1.23-10) and male gender (p<0.05, OR 3.2, 95% CI 1.04-10). Splenectomy and cardiac surgery did not impact on in-hospital mortality.

Conclusions: Asymptomatic embolism to the central nervous system and to the spleen were frequent. Splenomegaly was consistently associated with embolic events.