Endocardial Involvement
The prevalence of infective endocarditis in HIV-infected patients is similar to that of patients in other risk groups, such as intravenous drug users [40]. Estimates of endocarditis prevalence vary from 6.3 to 34% of HIV-infected patients who use intravenous drugs independently of HAART regimens [21].
Right-sided valves are predominantly affect-ed and the most frequent agents are Staphylococcus aureus (>75% of cases), Streptococcus pneumoniae (15-20% of cases), Haemophilus influenzae (10% of cases), Candida albicans, and Aspergillus fumigatus [21, 41]. Patients with HIV generally have similar presentations and survival (85 vs 93%) from infective endocarditis as those without HIV [41] (Figs. 8-11). However, in relation to the state of immunodeficiency, patients with late-stage HIV disease have a mortality rate from infective endocarditis of about 30% higher than do asymptomatic HIV-infected patients [41]. Nonbacterial thrombotic endocarditis-which was described with a prevalence of 3-5% in AIDS patients before the introduction of HAART, and mostly in patients with HIV wasting syndrome-is now more frequently observed in developing countries with a high incidence (about 10-15%) and mortality rate for systemic embolization [26]. Death from marantic endocarditis is rare in HIV-infected patients receiving HAART.
Fig. 8 Voluminous mobile vegetation on the anterior and posterior mitral leaflet in an HIV-infected patient, detected by transthoracic echocardiography (apical four-chamber view)
Fig. 10 Significant aortic regurgitation (grade IV) in an HIV-infected patient, detected by color Doppler transesophageal echocardiography. Ao, aorta; LV, left ventricle
Fig. 9 Large anterior mitral vegetation in an HIV- infected patient, detected by transesophageal echocardiography. Ao, aorta; LA, left atrium; LV, left ventricle
Fig. 11 Significant mitral regurgitation in HIV- infected patients with endocarditis, detected by color Doppler trans-thoracic echocardiography (parasternal long-axis view). RV, right ventricle; LV, left ventricle; Ao, aorta; LA, left atrium