Concerns that the metabolic disorders associated with anti-HIV therapies may lead to an increased risk of angina and heart attack were boosted today at the International AIDS Conference in Barcelona, Spain.
Dr Giuseppe Barbero reported a randomised study looking at the risk of coronary artery disease among 1,551 HIV-infected people taking highly active antiretroviral therapy (HAART). Comparing two key drug classes – the protease inhibitors (PIs) and non-nucleoside reverse transcriptase inhibitors (NNRTIs) − Dr Barbero found that people taking protease inhibitors had a significantly increased risk of coronary artery disease.
Twenty-three cases of coronary artery disease occurred among 587 people who took PIs for 42 months. In contrast, only two cases of coronary artery disease developed among 621 NNRTI recipients. This translates into a cumulative annual incidence rate of 9.8 cases per 1000 patient-years among those taking PIs compared to 0.8 cases per 1000 patient-years among those taking NNRTIs.
The incidence of myocardial infarction or heart attack was 5.1 per 1,000 patient years for those taking PIs.
In line with these findings, metabolic disorders and lipodystrophy were significantly more common in the PI group.
Commenting on the findings, Dr Jens Lundgren warned that the low number of coronary events means that the incidence figures are not highly reliable. He also cautioned that nearly half of the original participants did not complete follow-up, raising some doubts about the reliability of the figures.
The general relevance of these findings to other populations is also confounded by the high rate of smoking among study participants. Smoking, defined as more than 15 cigarettes per day, was reported by 87% of participants.
Nevertheless, Dr Lundgren described the study as “very important”. He said the results provided “the strongest evidence I have seen” of a causal link between heart disease and protease inhibitors. He also commented that there appears to be a “lagtime” of about 20 months between the development of metabolic markers which put people at risk of heart disease and actual events such as heart attack or angina.
Barbero G et al. Incidence of coronary artery disease in HIV-infected patients receiving or not protease inhibitors: a randomized, multicenter study. Fourteenth International AIDS Conference, Barcelona, WeOr1307, 2002.
Lundgren JD. Perspective of HIV-associated coronary heart disease. Fourteenth International AIDS Conference, Barcelona, WeOr203, 2002.