Clinical features, microbiology and surgical outcomes of infective endocarditis: a 13-year study from a UK tertiary cardiothoracic referral centre.

BACKGROUND: Infective endocarditis (IE) causes substantial morbidity and mortality. Patient and pathogen profiles, as well as microbiological and operative strategies, continue to evolve. The impact of these changes requires evaluation to inform optimum management and identify individuals at high risk of early mortality. AIM: Identification of clinical and microbiological features, and surgical outcomes, among patients presenting to a UK tertiary cardiothoracic centre for surgical management of IE between 1998 and 2010. DESIGN: Retrospective observational cohort study. METHODS: Clinical, biochemical, microbiological and echocardiographic data were identified from clinical records. Principal outcomes were all-cause 28-day mortality and duration of post-operative admission. RESULTS: Patients (n = 336) were predominantly male (75.0%); median age 52 years (IQR = 41-67). Most cases involved the aortic (56.0%) or mitral (53.9%) valves. Microbiological diagnoses, obtained in 288 (85.7%) patients, included streptococci (45.2%); staphylococci (34.5%); Haemophilus, Actinobacillus, Cardiobacterium, Eikenella, Kingella (HACEK) organisms (3.0%); and fungi (1.8%); 11.3% had polymicrobial infection. Valve replacement in 308 (91.7%) patients included mechanical prostheses (69.8%), xenografts (24.0%) and homografts (6.2%). Early mortality was 12.2%, but fell progressively during the study (P = 0.02), as did median duration of post-operative admission (33.5 to 10.5 days; P = 0.0003). Multivariable analysis showed previous cardiothoracic surgery (OR = 3.85, P = 0.03), neutrophil count (OR = 2.27, P = 0.05), albumin (OR = 0.94, P = 0.04) and urea (OR = 2.63, P < 0.001) predicted early mortality. CONCLUSIONS: This study demonstrates reduced post-operative early mortality and duration of hospital admission for IE patients over the past 13 years. Biomarkers (previous cardiothoracic surgery, neutrophil count, albumin and urea), predictive of early post-operative mortality, require prospective evaluation to refine algorithms, further improve outcomes and reduce healthcare costs associated with IE.

Studies on hypoxia: XII. Detrimental effects of synthetic polyribonucleotides on epiphyseal plates of rats exposed to hypoxia.

The effect of different doses of polyadenylic and polyuridylic acids (poly A:U) was studied in control rats and in rats exposed to hypoxia. In the control rats, administration of different doses of poly A:U did not change the thickness of the epiphyseal plate or increase the incorporation of 3H-phenylalanine as judged using radioautography. Rats exposed to hypoxia showed a significant dose-related reduction in the thickness of the epiphyseal plate and 3H-phenylalanine incorporation.

Studies on hypoxia: XI. Long-term effects on the epiphyseal plate--a histomeric and radioautographic study.

Rats were exposed to hypoxia for one week. The mean thickness of epiphyseal plates form control rats was 430 micrometers (mum) which was reduced to 313 mum in hypoxic rats. Radioautographic incorporation of 3H-phenylalaine by connective tissue cells in hypoxic rats was reduced up to 38% in control rats.