We describe the case of a young HIV-positive man on effective HAART with excellent viro-immunological control who presented a massive cardiac infarction. Despite the presence of clinical risk factors for cardiovascular disease, the patient had normal arterial carotid IMT values, known to be strong predictors of atherosclerosis and stroke. Interestingly, parameters of T-cell activation (CD8+CD38+) were shown to increase just before the onset of myocardial infarction. As T-cell activation is known to mediate atherosclerosis, the authors suggest that surrogate immunologic markers should be identified to better assess cardiovascular risk in the setting of HIV infection.