Cardiovascular Manifestations of HIV Infection- A Review

ABSTRACT

HIV is a single-stranded RNA retrovirus from the Lentivirus family that invades cells containing specific membrane receptors and incorporates a DNA copy of itself into the host’s genome. Immune deficiency is the result of virus and immune-mediated destruction of CD4 lymphocytes caused by continuous high-level HIV replication. AIDS is defined by the development of one or more specified opportunistic infections, tumours, and other conditions. These include oesophageal candidiasis, cytomegalovirus CMV retinitis, pulmonary or extrapulmonary tuberculosis, Kaposi sarcoma, and HIV/AIDS associated dementia. Most forms of HIV-related heart muscle disease and pericardial effusion occur at this stage. Acquired immunodeficiency syndrome (AIDS) was first recognized in 1981 and is caused by human immunodeficiency virus (HIV-1). HIV-2 causes a similar illness to HIV-1 but is less aggressive and has so far been restricted mainly to western Africa. HIV/AIDS is acquired through exposure to infected body fluid, particularly blood and semen; the most common modes of spread are sexual, parenteral (blood or blood product recipients, injection drug users, and occupational injury) and vertical (mother to fetus). HIV/AIDS is now the second leading cause of death in the world, with a global prevalence of 0.8%. Many cultural and social factors determine regional patterns of HIV/AIDS disease and associated infections.­­­­­­­­1 In the United States and northern Europe, the epidemic has predominantly been in men who have sex with men. In northeast India, the incidence has been greatest in injection drug users, but in much of Southeast Asia, the dominant routes of transmission have been heterosexual and from mother to child (vertical). With improving longevity, non-AIDS conditions are now accounting for the majority of deaths among individuals receiving ART, and CV disease has become an increasingly significant problem in the HIV population. Deaths due to CV disease among individuals living with HIV have ranged from 6.5% to 15% of total deaths. The mechanisms underlying CV disease in HIV patients are largely poorly understood but are known to be multifactorial. They include many traditional risk factors and also factors related to HIV, such as the side effects of antiretroviral medication. These effects are significant and include metabolic issues, immune activation, chronic inflammation, microbial translocation, and co-infection with other viral pathogens such as cytomegalovirus. Such mechanisms are ongoing even when HIV infection has been treated; the CD4 count and HIV viral load may be controlled, but the infection has not been cured. At the beginning of the epidemic, heart muscle disease (cardiomyopathy) was the dominant cardiac complication of HIV infection in the developed world. In contrast, tuberculous pericarditis and cardiomyopathy were and still remain important cardiac manifestations of the disease in Africa.2,3 Combined highly active antiretroviral therapy (HAART) (usually two nucleoside reverse transcriptase inhibitors [NRTIs] in combination with one or two protease inhibitors) has changed the pattern of disease in developed countries, where premature coronary artery disease (CAD) and other manifestations of atherosclerosis are emerging as the most common cardiovascular disorder.