Large American study uncovers link between HIV and heart failure
The risk of cardiovascular disease - including narrowed arteries, heart attack and stroke - is increased in HIV-positive people. There may be several possible reasons for this, including the following:
- HIV infection causes inflammation and over the long term this may degrade organ-systems, particularly the heart, blood vessels and kidneys (which help to regulate blood pressure).
- Surveys have found that some HIV-positive people have risk factors for cardiovascular disease, such as smoking, high blood pressure and abnormal lipid levels.
- Some HIV-positive people may also inject illicit substances such as cocaine and heroin.
A team of researchers in the US has collaborated with Veterans Affairs (VA), which has been collecting health-related data on thousands of veterans, comparing rates of illness between HIV-negative and HIV-positive people. Their analysis suggests that some HIV-positive people may be at increased risk for heart failure.
Note that heart failure does not mean that the heart has stopped beating. Rather, it is a medical term that means that the heart cannot pump all of the blood that the body needs. As a result, the health of vital organs is affected and symptoms such as fatigue, unexpected shortness of breath, swelling in the lower limbs and abdomen and difficulty concentrating can develop. In more severe cases of heart failure, sudden chest pain can also occur. If left untreated, heart failure can lead to poor quality of life, visits to the hospital emergency room and shortened life span.
Researchers across the US analysed health-related information collected by the VA between 2000 and 2007 from 6,095 HIV-negative and 2,391 HIV-positive male veterans. Due to the relatively small number of women (276) in the database, the final analysis was restricted to men. Also excluded from analysis were men who had cardiovascular disease or a previous diagnosis of heart failure as well as others who were exposed to certain anticancer drugs known to damage the heart.
The average profile of the HIV-positive participants at the start of the study was as follows:
- age – 48 years
- CD4+ count – 366 cells
- HIV viral load – 660 copies/ml
The following co-morbidities were found in some participants:
- hepatitis C virus co-infection – 31%
- abnormal lipid levels (cholesterol, triglycerides) in the blood – 30%
- higher-than-normal blood pressure – 19%
- type 2 diabetes – 17%
- current smoker – 55%
- history of alcohol addiction – 34%
- history of cocaine addiction – 22%
Over the course of the study there were 97 cases of heart failure among HIV-positive people and 189 among HIV-negative people.
Investigating this finding further, the research team took into account traditional risk factors for heart failure. Despite removing people with these risk factors from the analysis, HIV infection was still associated with an increased risk for heart failure. However, among HIV-positive people who had a viral load less than 500 copies/ml at the start and end of the study, there was no increased risk for heart failure. This difference between people with a viral load of 500 copies/ml or greater and people with a lower viral load was statistically significant; that is, not likely due to chance alone.
The study researchers are not certain exactly why HIV infection appears to be associated with heart failure— particularly among people whose viral load is 500 copies/ml or greater—but the team suggests several possibilities, as follows:
- a direct effect of HIV on the heart
- immunologic damage to the heart
- nutrient deficiencies, particularly vitamins C and E, mixed carotenoids, selenium and L-carnitine
The researchers emphasized that some modifiable traditional risk factors for heart failure were present in their population, including the following:
- higher-than-normal blood pressure
- type 2 diabetes
- alcohol abuse
Thus, reducing high blood pressure, preventing or controlling diabetes, losing weight and getting support for quitting smoking (a habit that causes many health problems that could affect risk factors for heart failure) are what the research team describes as “prudent strategies that should be emphasized.”
Heart failure can be managed with monitoring and advice and medications from cardiologists.
Further studies are needed by other research teams to confirm the present study’s findings. This is particularly important because the present analysis was based on a retrospective cohort study. While the research team went to great lengths to exclude potential sources of bias, retrospective study designs cannot provide definitive answers to research questions. But they can serve as an important starting point for further research.
For more information about improving cardiovascular health, see CATIE’s in-depth Fact Sheet.