Dilated cardiomyopathy associated with simian AIDS in nonhuman primates

Background-Cardiomyopathy is being recognized with increasing frequency in patients with AIDS, yet the relationship between HIV infection and cardiac contractile dysfunction remains obscure. The purpose of the present study w as to determine if infection with simian immunodeficiency virus (SIV) in no nhuman primates is associated with cardiac dysfunction and myocardial injur y. Methods and Results-Left ventricular size and function were determined by 2 D echocardiography in 16 rhesus macaques before and at weekly intervals fol lowing infection with cloned pathogenic SIVmac 239 or the highly attenuated SIVmac 239 nef deletion mutant. A second group of 15 rhesus macaques chron ically infected with pathogenic (n=6) or nonpathogenic (n=9) virus were stu died at >2 years following infection. Cardiac tissues from 24 rhesus macaqu es chronically infected (>2 years) with pathogenic SIV were reviewed for ev idence of cardiac pathology. Acute infection (<6 weeks) with either pathoge nic or nonpathogenic SIV caused neither contractile dysfunction nor cardiac pathology. However, LV ejection fraction was significantly (P<0.05) depres sed (43+/-7%) in rhesus macaques chronically infected with pathogenic SIV c ompared with rhesus macaques chronically infected with nonpathogenic SIV (6 1+/-3%). Furthermore, two thirds of rhesus macaques that succumbed to simia n AIDS had myocardial pathology including lymphocytic myocarditis (n=9) and coronary arteriopathy (n=6), with complete vessel occlusion (n=4) and asso ciated myocardial infarction and necrosis. Conclusions-This unique model is valuable in understanding the pathogenesis of cardiac injury associated with retroviral infection in a relevant nonhu man primate model of AIDS.