Comparison of Mortality, Stroke, and Relapse for Methicillin-Resistant versus Methicillin-Susceptible Staphylococcus aureus Infective Endocarditis: a Retrospective Cohort Study

Abstract Objective The purpose of this study was to compare survival, relapse, and stroke for patients with methicillin-resistant Staphylococcus aureus (MRSA) versus methicillin-susceptible S. aureus (MSSA) infective endocarditis (IE). Methods In this retrospective study, the primary outcome of death and secondary outcomes of stroke and relapse were compared using multivariable Cox proportional hazards regression. Surgical treatment was adjusted for as a time-dependent variable. Results In total, 355 patients with at least one episode of IE caused by S. aureus were included. Patients with MRSA IE had higher mortality than those with MSSA IE (HR 1.34, 95% CI 1.01-1.77), but did not have a higher risk of stroke (HR 0.75, 95% CI 0.43-1.32) or relapse (HR 0.89, 95% CI 0.26-3.05). The cumulative incidence of relapse was very small. Conclusions Among patients with IE caused by S. aureus MRSA infection is associated with higher mortality than MSSA infection.