Abacavir and cardiovascular risk: reviewing the evidence.

Since the presentation of the D:A:D study results at the Conference on Retroviruses and Opportunistic Infections in February 2008, 10 studies have explored the association between exposure to abacavir and the risk of myocardial infarction. Among the five larger studies, three conclude that there is an association and two that the association is not robust. Based on these studies, it is impossible to refute or confirm a causal relationship, as it is not possible to exclude remaining confounding (smoking in two of the studies, kidney function in two of the studies, cocaine and/or intravenous drug use) and selection bias in studies that report a robust association. In addition, no convincing mechanism has been described.