Infective endocarditis due to Staphylococcus aureus: deleterious effect of anticoagulant therapy

Abstract

Background: The use of anticoagulant therapy in patients with infective endocarditis (IE) is a controversial issue.

Objective: To study the impact of anticoagulant therapy on the clinical outcome, mortality, and cause of death in a series of patients with native and prosthetic left-sided Staphylococcus aureus IE.

Methods: This report is based on all consecutive cases of IE diagnosed at our hospital between 1975 to 1997. Clinical data, including the use of anticoagulant therapy at the time of diagnosis, were prospectively obtained, and antibiotic treatment and surgical indications were uniform throughout the study period. Computed tomographic scans of all clinical records were reviewed.

Results: Of 637 consecutive patients with IE, 56 had left-sided S aureus IE affecting native valves in 35 patients and prosthetic valves in 21 patients. Of the patients with prosthetic valve IE, 19 (90%) were taking oral anticoagulant therapy at the time of diagnosis while no patient with native valve IE was receiving such treatment. There were no differences between native valve IE and prosthetic valve IE in age, sex, embolic episodes, and number of central nervous system complications. Mortality was higher in prosthetic valve IE than in native valve IE (71% vs 37%; P=.02). No patient with native valve IE died due to central nervous system complications, while 73% (11 of 15 patients) with prosthetic valve IE died due to central nervous system complications. The difference in the distribution of the type of death (stroke vs other) was significant (P<.007).

Conclusions: Our results suggest that in left-sided S aureus IE anticoagulant therapy is closely associated with death due to neurologic damage. According to our data, as soon as the clinical diagnosis of S aureus IE is indicated the use of anticoagulant therapy should be immediately stopped until the septic phase of the disease is overcome.