Anticoagulation May Not Affect Stroke Risk in Left-Sided Infective Endocarditis

endocarditis, infective endocarditis
In this study of patients with left-sided infective endocarditis, investigators analyzed how anticoagulation affects stroke occurrence and bleeding complications.

Continuation of anticoagulation therapy may not have an effect on stroke, cerebrovascular hemorrhage, or mortality in patients with left-sided infective endocarditis, according to study results published in the American Journal of Medicine.

Stroke occurs in 17%-20% of patients with infective endocarditis; however, current guidelines provide few definitive recommendations on the role of anticoagulation in the prevention and management of stroke in acute infective endocarditis. The researchers of this study sought to evaluate whether anticoagulation increases the risk for stroke and bleeding complications in patients with left-sided infective endocarditis.

In this retrospective cohort study, researchers identified adult patients with left-sided infective endocarditis admitted to a tertiary academic hospital between December 2011 and April 2018 (N=258). Of these patients, they classified 20.9% as users of injection drugs, including opioids, cocaine, and amphetamines. Researchers stratified patients into 2 groups according to whether or not they were receiving anticoagulation (warfarin or parenteral anticoagulation) at the time of admission. The primary outcome measure was the occurrence of stroke at 10 weeks, and secondary outcome measures included intracranial hemorrhage, length of hospital stay, and mortality. 

At the time of admission, 19.4% of patients were receiving anticoagulation (warfarin, n=27; parenteral anticoagulation, n=21; and direct oral anticoagulant, n=2). Researchers continued preexisting anticoagulation in 54% (n=27) of patients upon admission. Of the patients on anticoagulation at admission who survived beyond 2 weeks (n=40), 27.5% (n=11) restarted anticoagulation before or upon discharge. Anticoagulation was not started in patients who were not on preexisting anticoagulation therapy.

Results revealed that patients receiving anticoagulation were older (median age, 63 vs 52 years; P =.02), more likely to have prosthetic valves (38% vs 13.9%; P <.01), more likely to have a history of previous infective endocarditis (20% vs 9.6%; P =.04), and had significantly less mitral valve involvement (40% vs 62%; P <.01) than patients who did not receive anticoagulation. 

Of the 258 patients evaluated, 34.9% (n=90) experienced a stroke and 20.5% (n=53) died within 10 weeks after diagnosis of infective endocarditis.

Characteristics of patients who experienced a stroke included history of injection drug use, mitral valve involvement, Staphylococcus aureus infection, and low platelet counts.

There was no significant difference in the overall rate of stroke, cerebrovascular hemorrhage, or mortality between patients who received anticoagulation on admission and patients who did not.

Limitations to the study included using data from a tertiary clinic in North Carolina where injection drug use is an epidemic, indicating that people who inject drugs may be overrepresented. Most of the patients experienced clinically apparent strokes, and vegetation size was not included in the analysis.

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The study researchers concluded that anticoagulation before admission for acute infective endocarditis was not associated with higher rate of intracranial hemorrhage at 10 weeks and that continuation of anticoagulation upon admission may be permissible in left-sided infective endocarditis as long as there are no contraindications.

Disclosure: One study author declared associations with the pharmaceutical industry. Please see original reference for a full list of authors’ disclosures.


Davis KA, Huang G, Petty SA, Tan WA, Malaver D, Peacock JE Jr. The effect of pre-existing anticoagulation on cerebrovascular events in left-sided infective endocarditis [published online September 5, 2019]. Am J Med. doi:10.1016/j.amjmed.2019.07.059