Here are some interesting tidbits recently published from the largest prospective cohort of infective endocarditis ever collected (abstract). Causative organisms were Gram positive in 81-88% of cases (3-4% Gram negative, 1-2% fungi or yeast, and 8-13% other / culture negative). MSSA accounted for almost 1/3 of cases, and MRSA accounted for 36% of cases in those >65 years old, and 21% of cases in those 18-65 years old. Compared to patients 18-65 years old, those >65 years old were more likely to have a +blood culture (92% vs 86%) but less likely to have vegetations (84% vs 88%) peripheral embolic events (15% vs 26%) or stroke (15% vs 18%). However, they were twice a likely to die (25% vs 13%). Take home messages here are to remember atypical presentations (lack of blood culture or vegetations; hence the need for the modified Duke criteria for diagnosis (Duke criteria)), and the overwhelmingly high rates of MRSA and death in the elderly.
Dr. Scheurer is a clinical hospitalist and the Medical Director of Quality and Safety at the Medical University of South Carolina in Charleston, South Carolina, and is Assistant Professor of Medicine. She is a graduate of the University of Tennessee College of Medicine, completed her residency at Duke University, and completed her Masters in Clinical Research at the Medical University of South Carolina. She also serves as the Web Editor and Physician Advisor for the Society of Hospital Medicine.