Research Article: Time-sensitive predictors of embolism in patients with left-sided endocarditis: Cohort study

Date Published: April 25, 2019

Publisher: Public Library of Science

Author(s): Alvin Yang, Charlie Tan, Neill K. J. Adhikari, Nick Daneman, Ruxandra Pinto, Bennett K. M. Haynen, Gideon Cohen, Mark S. Hansen, Salah A.M. Said.


Accurate prediction of embolic events in infective endocarditis could inform critical clinical decisions, such as the timing of cardiac surgical intervention. However, many embolic events occur before hospital admission and echocardiography and are thus non-modifiable. We aimed to identify time-sensitive variables that predict embolic events in infective endocarditis, focusing on those that occur after diagnosis.

Clinical, microbiological, and echocardiographic characteristics were collected from 116 patients with definite or probable left-sided infective endocarditis admitted to Sunnybrook Health Sciences Centre (Toronto, Canada) between October 2013 and July 2016; associations between these characteristics and embolic events were identified using simple logistic regression.

The mean (SD) age was 66 (17) years; 82 patients (71%) were men. The most frequent microorganisms were Staphylococcus aureus (23%) and viridans group streptococci (21%). Seventy-nine (68%) patients had left-sided vegetations, with involvement of the aortic valve in 34 (43%) patients, mitral valve in 37 (47%) patients, and both in 8 (10%) patients. The mean (SD) vegetation size was 10 (7) mm. Forty-three unique patients (37%) had 50 embolic events, with most (34/43; 79%) having a first embolic event (38/50; 76%) before or on the day of echocardiography. There were no significant predictors of the 11 patients with an embolic event after echocardiography; significant predictors of an embolic event at any time were single valve vegetation vs. no vegetation (OR, 4.75; 95% confidence interval [CI], 1.76–12.78) and, among patients with a vegetation, mitral vs. aortic valve location (OR, 4.43; 95%CI, 1.63–12.04).

Associations between patient and echocardiographic characteristics and embolism in patients with infective endocarditis may be time-sensitive, as few embolic events occurred after clinical and echocardiographic assessment.

Partial Text

Infective endocarditis (IE) is characterized by high morbidity and mortality despite advances in medical and surgical care [1]. Among the most common and catastrophic complications of IE are embolic events (EEs). Echocardiographic variables associated with EEs include vegetation size [2–5], mobility [4, 6, 7], and mitral location [8–12]. Other clinical variables associated with EEs include Staphylococcus aureus infection [2, 6, 7, 9, 12–18], age [2, 18, 19], intravenous drug use (IVDU) [16, 20], and prosthetic valve IE [12, 17, 21].

We investigated 116 patients with definite or probable IE to identify clinical, microbiological, and echocardiographic characteristics associated with EEs. EEs occurred in 37% of patients, congruent with previously reported rates of 18–44% [17, 24, 30, 31]. The large majority of EEs occurred before or on the day of hospital admission, thereby precipitating medical contact. We found several predictors of all EEs that were no longer statistically significant when considering only EEs that occurred after echocardiography, limiting their utility for clinical decision-making.

The present study validates a global association between conventional clinical and echocardiographic variables and systemic embolism, while suggesting that the predictive value of echocardiographic variables may be time-sensitive. These results illustrate limitations inherent in studies that combine prospective and retrospective associations with embolism and serve as a caveat emphasizing the importance of a comprehensive evaluation when applying practice guidelines in planning surgical intervention.