HIV Weekly - 12th September 2012

HIV and cardiovascular disease

Cardiovascular disease is increasingly common in people with HIV.

The exact reasons for this aren’t certain. However, they could include traditional risk factors such as smoking, the damage caused by untreated HIV infection and the side-effects of antiretroviral therapy.

Because of this uncertainty, doctors in Australia combined the results of key studies looking at this question to see if they could come up with firmer answers.

Even though there’s a lot of interest in the relationship between HIV and cardiovascular disease, only 23 studies were eligible for inclusion.

What’s more, only three studies had compared the overall cardiovascular risk for people living with HIV to that of HIV-negative people of the same sex and age. Their combined results showed that infection with HIV increased the risk of cardiovascular disease by 61%.

A further three studies compared the risk of cardiovascular disease between people taking HIV treatment and an HIV-negative control group. Those taking HIV treatment were twice as likely to develop cardiovascular disease.

Eight studies compared the risk of cardiovascular disease between people who were taking HIV treatment and people with HIV who weren’t on treatment. The people taking treatment were about 50% more likely to have cardiovascular problems.

However, the researchers stress that it is important to see these results in context – HIV treatment means a longer and healthier life. Many people taking HIV treatment are now entering middle or old age, and cardiovascular disease is a recognised disease of ageing.

A separate US study has shown that people with HIV have heart attacks at a younger age than HIV-negative people.

Researchers looked at hospitalisations due to heart attack between 1997 and 2006. People with HIV who had a heart attack were an average of ten years younger than HIV-negative people (54 vs 64).

The study also showed that, compared to HIV-negative people, people with HIV were approximately 50% more likely to die following a heart attack. The researchers think that this could be because of the damage caused by HIV.

Routine HIV care includes tests to monitor your risk of cardiovascular disease. This means that problems can be spotted early and appropriate treatment can be provided.

You can also reduce your risk of cardiovascular disease by stopping smoking, eating a healthy diet and taking regular exercise. Talk to your GP or someone at your HIV clinic for more information and advice on improving your health.

Treatment with aspirin to reduce cardiovascular risk

Daily treatment with a low-dose of aspirin is widely used in the general population for the prevention of cardiovascular disease. Aspirin reduces the clotting action of platelets in the blood, therefore reducing the risk of heart attack.

US guidelines, issued in 2009, recommend that men aged between 45 and 79 and women aged between 55 and 79 should take a daily low dose of aspirin for the prevention of cardiovascular disease. The exception is those with a risk of gastrointestinal bleeding as this is a recognised side-effect of aspirin.

There are no guidelines specifically about the use of aspirin for the prevention of cardiovascular risk in people with HIV.

Therefore, a team of researchers wanted to see how many people living with HIV who would potentially benefit from aspirin therapy are taking the drug.

They found that only 17% were prescribed aspirin by their doctor. This was despite the fact that half were assessed as having an intermediate to high ten-year risk of having a heart attack. Many people had specific risk factors for cardiovascular disease: 39% smoked; 63% had high cholesterol; 20% were obese; 62% had high blood pressure and 16% had diabetes.

The researchers believe their results show that HIV doctors need education about the use of aspirin for the prevention of cardiovascular disease.

Adherence – taking your HIV treatment

Adherence – taking all doses of your HIV treatment exactly as prescribed – is central to the success of your HIV therapy.

Missing doses or taking them too early or late can mean that blood levels of your drugs are too low to suppress viral load to undetectable levels. This can lead to drug resistance.

Newer anti-HIV drugs are very powerful, and some people have managed to achieve an undetectable viral load even though they only take about 70% of their doses.

Doctors wanted to see what impact different levels of adherence had on cells which had already been infected with HIV. This is called cell-associated HIV.

They therefore monitored viral load and cell-associated HIV levels in 40 people taking HIV treatment.

All the people in the study maintained an undetectable or very low viral load.

Their results showed that levels of cell-associated virus fell in people who took all their doses of HIV treatment. However, it increased in people with poor adherence.

The researchers believe their results “suggest that constantly optimal adherence to ART may be required life-long”. Effective combination therapy has meant a huge increase in life expectancy for people with HIV, but it is still not the same as for the general population. The researchers suggest that their results may provide an explanation for this, as poor adherence and HIV-infected cells causing inflammation could lead to an over-stimulation of the immune system, causing further health problems.   

Lipodystrophy

Treatment with the cosmetic filler Bio-Alcamid (polyalkylimide) for facial lipoatrophy is associated with a high rate of infectious complications, new research shows.

Facial fat loss is a recognised side-effect of some older anti-HIV drugs, especially d4T (stavudine, Zerit) and AZT (zidovudine, Retrovir).

Fillers, such as Bio-Alcamid, have been used to treat facial fat loss. Clinical trials showed that this treatment was safe and effective in the short term.

However, researchers in Canada monitored people who had had this therapy for an average of three years. They found that a high proportion were developing infections.

Recent dental work or touch-up treatment were risk factors for the development of infections.

In the UK, treatment for facial fat loss usually involves injections of polylactic acid (New Fill). Treatment is available in the larger HIV centres, including in London and Brighton.