Aspirin on the Risk of Embolic Events in Patients With Infective Endocarditis - Aspirin on the Risk of Embolic Events in Patients With Infective Endocarditis


The goal of the trial was to evaluate the effect of aspirin therapy versus placebo on the risk of embolic events in patients with infective endocarditis.


Aspirin can reduce the risk of embolism in patients with endocarditis by enhancing vegetation resolution.

Study Design

Study Design:

Patients Screened: 513
Patients Enrolled: 115
Mean Patient Age: mean age 56 years
Female: 27

Patient Populations:

Age 16 and 80 years with native valve or prosthetic valve endocarditis, defined as two of the following three criteria: 1) multiple positive blood cultures (at least two sets) with no known extracardiac source; 2) echocardiographic evidence of vegetation, defined as a localized, mobile mass contiguous with a valve leaflet or prosthetic valve; and 3) at least two of the following clinical findings: fever, new or changing heart murmur, pre-existing heart disease, and microvascular phenomena


Isolated right-sided endocarditis, echocardiographic evidence of perivalvular abscess (defined as an abnormal echolucent mass within the perivalvular tissue), probable surgical intervention within seven days, current use of aspirin, recent or actively evolving stroke, history of gastrointestinal bleeding or active peptic ulcer disease within the past 12 months, history of a bleeding diathesis, allergic or intolerance to aspirin, and inability or unwillingness to provide informed consent

Primary Endpoints:

Clinical embolic events involving the brain or other organs

Secondary Endpoints:

Cerebral hemorrhage, subclinical strokes detected by cerebral computed tomography, death, major or minor bleeding, valve surgery, and echocardiographic progression of valvular involvement

Drug/Procedures Used:

Patients were randomized to either aspirin (325 mg/day; n=60) or placebo (n=55) for four weeks.

Concomitant Medications:

All patients were on antibiotic therapy. Anticoagulation therapy was continued in patients with mechanical prosthetic valves.

Principal Findings:

Only 31% of the target enrollment (n=369) occurred before the trial was ended (n=115) due to slow enrollment. Mean symptom duration was 34.5 days in the aspirin arm and 33.5 in the placebo arm. Embolic events occurred in 28.3% of patients in the aspirin arm and 20.0% of patients in the placebo arm (odds ratio [OR] 1.62, 95% confidence interval [CI] 0.68-3.86, p=0.29). Any bleeding (major or minor) trended higher in the aspirin group versus placebo (28.8% vs. 14.5%, OR 1.92, 95% CI 0.76-4.86, p=0.075).

There was no difference in heart failure (39.7% vs. 30.9%, OR 1.47, 95% CI 0.68-3.20, p=0.431), in-hospital death (6.7% vs. 10.9%, OR 0.58, 95% CI 0.16-2.19, p=0.516), renal dysfunction (22% vs. 29.1%, OR 0.69, 95% CI 0.30-1.61, p=0.400), or valve surgery (30.5% vs. 23.6%, OR 1.42, 95% CI 0.62-3.26, p=0.528). Results were similar in the subgroup of patients with native valve endocarditis. Both number and size of vegetation resolution and severity of valvular dysfunction were similar in the two treatment arms.


Among patients with infective endocarditis, treatment with aspirin therapy was not associated with a reduction in embolic events compared with placebo. Embolism is a major complication and one of the main causes of death in patients with infective endocarditis.

There is no proven treatment currently available to prevent embolism in these patients. The mean duration from symptom onset to treatment in the present trial was 34 days, and it is unknown whether earlier use of aspirin may have different effects.


Chan KL, Dumesnil JG, Cujec B, et al., for the Investigators of the Multicenter Aspirin Study in Infective Endocarditis. A randomized trial of aspirin on the risk of embolic events in patients with infective endocarditis. J Am Coll Cardiol 2003;42:775-80.

Clinical Topics: Heart Failure and Cardiomyopathies, Noninvasive Imaging, Acute Heart Failure, Echocardiography/Ultrasound

Keywords: Cause of Death, Odds Ratio, Endocarditis, Platelet Aggregation Inhibitors, Heart Murmurs, Heart Failure, Confidence Intervals, Embolism, Echocardiography

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