Endocarditis in internal medicine departments: a case series

Background: Infective endocarditis (IE) is a rare pathology, with an incidence of 3–10 cases/100.000 person-year (1). The incidence didn’t significatively change in the last century: the decrease of postrheumatic valvular heart disease at population level is compensated by an increase in degenerative valvular heart disease as predisposing factor. Moreover, the share of patients with intravascular foreign material is increasing. IE is often diagnosed late. The clinical features are usually atypical. Since the introduction of the Duke criteria, clinical, bacteriological and echocardiographic findings (transthoracic and transoesophageal echocardiography) are being integrated, allowing an earlier definite diagnosis (1). Normochromic normocytic anemia, elevated ESR, neutrophilia, increased immunoglobulins, circulating immune complexes and rheumatoid factor are often present in IE. Many factors affect the outcome of this serious disease, including virulence of the species, patient’s characteristics, comorbidities, delays in diagnosis and treatment, surgical indications, and timing of surgery (2). Endocarditis is frequently characterized by a complicated course. About 50 % of the patients develop heart failure. One third of the patients present with cerebral or peripheral embolization. Embolization predominantly occurs at the beginning, in the first two weeks of antibiotic treatment. Abscess formation occurs more frequently than suspected if diagnosis is lead by ultrasonographic methods. Staphylococcus aureus infection is particularly aggressive in the presence of an artificial valve, often leading to extravalvular extension with abscess formation around the artificial valve. Despite improvements in medical and surgical therapies, IE is associated with poor prognosis and remains a diagnostic and therapeutic challenge. For its systemic involvement, endocarditis is typically an internistic pathology, and must be managed in an Internal Medicine Department (IMD) with critical care competence. Aims: To evaluate incidence, prevalence and clinical manifestations of endocarditis in our IMD. Methods: We retrospectively evaluated all the patients admitted in the critical area of our IMD in the year 2011–2012. We selected all the patients dismissed with a diagnosis of IE and reviewed the clinical, laboratoristic and echocardiographic data. Results: Seven patients were discharged with a definite diagnosis of native-valve IE. The most frequent clinical manifestations were dyspnea (57 %) and fever (43 %); our ED admitted the patients in our IMD with the diagnosis of AHF in 57 % of the cases, fever of unknown origin in 14.3 %, other diagnoses in 28.3 %. Mean ESR at diagnosis was 70 mm/h (SD ± 41 mm/h), CRP was 7.57 ng/ml (SD ± 6.16 ng/ml). Many patients (86 %) presents anemia, neutrophilia and increased hypergammaglobulinaemia. New ECG alterations were observed in 28.6 % of the sample. Only two cases resulted positive for rheumatoid factor. 71 % of the performed coltures resulted negative. Among the positive specimens, the most prevalent species found were Enterococcus spp and Staphylococcus spp (14.3 % of the cases each). Transthoracic echocardiography (TTE) resulted positive in 57 % of the cases, while transesophageal study confirmed the diagnosis in all the cases. No one of the described patients had recent hospitalization, carried a CVC or urinary catheter. In only one case IE was related with colon cancer, in another case the way of infection was related to drug addiction. No patient who was found to be diabetic or seriously immunocompromised. Discussion: IE still represents a complex diagnosis. In our series of patients is not possible to identify a common denominator, which could simplify the diagnostic process. The most frequent data (anemia, neutrophilia, hypergammaglobulinemia) is also the most unspecific. Although current guidelines clearly express how to the diagnose and manage IE, this pathology still remains very hard to diagnose without a correct clinical method and proven experience in cardiac ultrasound. IMD with competence both in echocardiography and critical care can carry the right methodological approach, diagnosing and managing most of the cases.