Trecentosessantasei casi di endocardite infettiva osservati nel periodo 2003-2015 presso l'A.O.- polo universitario L. Sacco di Milano

Three hundred and sixty-six cases of infectious endocarditis observed in the period 2003 - 2015 at the L.Sacco hospital, Milan Background/Aim: Infective endocarditis (IE) is a disease characterized by high morbidity and mortality. The epidemiology of this infection has changed dramatically in the last four decades, especially in industrialized countries. We sought to provide a contemporary picture of the presentation, etiology and in-hospital outcome of IE observed in a single centre. Patients and Methods: Retrospective cohort study of 366 episodes of definite or probable IE in 325 patients admitted to the “L.Sacco” Hospital in Milan, Italy, from January 1, 2003 through December 31, 2015. Statistical analyzes were performed using Wilcoxon nonparametric test for continuous variable, while for discrete variables Chi-square test or Fisher's exact test were applied. The multivariate regression analyzes were conducted taking into account the correlation between the observations of the dependent variable, correlation due to the fact that there are disclosures relating to the same subject. The analysis was made by applying the method of generalized estimating equation (GEE). Results: The overall incidence of IE was found to be 1.43 in 1000 hospitalized with a significant increase in the period from 2003 to 2015 (p = 0.002). The cohort has a median age of 62 (interquartile range, 45-74) years, with 2/3 (68%) of male patients and 60% was observed a native valve IE. Patients came to clinical attention after a median latency of onset of symptoms of 14 (5-32) days, with a few of the classic clinical signs of the disease. The analysis of factors predisposing the EI showed in 19% of cases, an active drug abuse, in 40% the infection of a prosthetic valve or pacemaker, 18% a previous episode of EI, 25% a recent healthcare exposure (invasive procedures, bearers of central venous catheters, hemodialysis) and in 5% a chronic rheumatic disease.The pathogens most frequently isolated was Staphylococcus aureus (30%) followed by Streptococcus spp (26%) and Enterococcus spp (18%). In 20% of cases, no etiologic agent was identified. Fungal endocarditis were 7 (2%) identified by blood culture and culture of explanted valve. The aortic valve (38%) and the mitral valve (32%) were the most affected valves. The following complications were frequent: stroke (20%), systemic embolization (26%), heart failure (33%), intracardiac abscess (9%). Surgical treatment was applied in the half (51%) of cases and hospital mortality was high (19%). From the comparison between the two periods (2003-2010 vs. 2011-2015) the following characteristics were significantly increased in the second period: the median age (56 vs. 69 years, p <0.0001), healthcare associated cases (20% vs 36%, p = 0.003), IE by Enterococcus spp (16% vs 24%, p = 0.03) and S. aureus (29% vs 39%, p = 0.03). The cases of IE in drug abusers are significantly decreased (22% vs 8%, P = 0.0003). The mortality rate has remained unchanged. Healthcare associated IE (p = 0.04) and the onset of complications (p <0.0001) were significantly associated with mortality, while the cardiac surgery has proved protective (p = 0.005). Conclusions: In line with what has been described in the literature also in our center IE is confirmed to be an acute disease with a significantly increased incidence, which predominantly affects elderly male with often unrecognized degenerative valve disease or heart valve prostheses. Staphylococcus aureus is the most frequently isolated germ associated with increased risk of complications. IE caused by Enterococcus spp have significantly increased. Despite advances in diagnosis and therapy in recent decades, the in-hospital mortality remains unchanged.