New research findings help to explain why some HIV patients treated with antiretroviral medications experience increased incidence of heart attacks.

The late-breaking data was presented by researchers from the School of Medicine and Medical Sciences at University College Dublin, the Mater Misericordiae University Hospital in Dublin, and the Royal College of Surgeons in Ireland at the Retrovirus Conference in Montreal, Canada, on 11 February 2009.

A major international study, published in 2008, identified a higher than expected incidence of heart attacks among patients being treated with antiretroviral drugs for HIV. Building on this research, scientists at the Royal College of Surgeons in Ireland developed a novel assay (test) tied to HIV to measure platelet activity in blood. Platelets are essential for blood clotting when the skin is broken but, if they are dysfunctional within the bloodstream, they can cause clots within arteries which lead to heart attacks.

Using this new test, the team from University College Dublin and the Mater Misericordiae University Hospital in Dublin, undertook clinical trials to investigate the activity of platelets among HIV patients in Dublin, Ireland. These findings show a significant increase in platelet reactivity among patients taking certain antiretroviral medications.

‘These findings will significantly affect the management of patients with HIV and have important implications for the treatment of HIV worldwide,” says Dr Paddy Mallon, consultant in Infectious Diseases at the Mater Misericordiae University Hospital in Dublin and a lecturer in medicine at University College Dublin, who leads the group researching drug toxicities in HIV.