The Changing Face of Infective Endocarditis: Ten Years Experience
Eric A Swanson, Shirin Shahbazi, Chi Lai, Michael C Fishbein. University of California, Los Angeles, Los Angeles, CA
Background: Infective endocarditis (IE) has high morbidity and mortality. Over the years, there has been a shift in predisposing conditions, causative organisms, guidelines for prophylaxis, and treatment. For example, routine prophylaxis for dental procedures is no longer recommended in cardiac conditions which have lower risk of adverse outcome from endocarditis, such as mitral valve prolapse and aortic stenosis.
Design: Eighty-four cases of IE requiring surgical intervention were identified from the surgical pathology database over the past ten years. Clinical and pathologic features were obtained from the medical record and pathology reports, including demographics, source of infection and predisposing factors, disease course, and surgical treatment.
Results: Seventy-one cases of native valve, along with 13 cases of prosthetic valve IE were examined. In the native valve cases, the median age was 53 years and 64.8% were men. Of these cases, 24% were temporally associated with dental procedures, or occurred in patients with poor dentition; 18.6% of the cases occurred in patients with diabetes mellitus (DM), and 17.1% in patients with end stage renal disease. Only 5.7% of this patient population had infections related to intravenous drug abuse. The majority of the causative organisms were oral and skin flora, consisting of Strep viridans (28.6%) and coagulase negative Staph (11.4%). Methicillin resistant Staph aureus (MRSA) was the pathogen in 17.1% of cases. In 51.3% of the cases, an underlying native valve or heart disease was identified as a risk factor for the infection, of which 15% were mitral valve prolapse and 15% bicuspid aortic valve. Only one case of underlying rheumatic heart disease was identified. All valves showed acute and chronic changes, 91.4% had vegetations noted by imaging or pathologic examination, and 73.2% had organisms seen histologically in spite of antibiotic therapy. There was a trend towards more valve repairs, as opposed to replacement, in more recent years.
Conclusions: In this contemporary series of IE cases undergoing surgery, many more cases are associated with mitral valve prolapse or bicuspid aortic valve than rheumatic heart disease. Many patients had DM and renal failure predisposing to infection. Oral and skin flora were the causative organisms in the majority of cases; however MRSA was frequently identified. In spite of recommendations for more restricted use of prophylaxis, in this series, there was continued association between dental procedures/disease and endocarditis.
Wednesday, March 21, 2012 1:00 PM
Poster Session VI # 36, Wednesday Afternoon