HIV infected patients treated with abacavir might have a higher risk for the occurrence of cardiovascular events. At time of writing of this protocol the underlying mechanism is not yet elucidated, however some studies find impaired endothelial function and elevated markers of chronic inflammation in these patients,suggesting a higher lever of chronic inflammation. Recently maraviroc (Celsentri®), a CCR5-receptor antagonist, became available for treatment of patients infected with HIV-1.