Abacavir Linked to Increased CVD Risk

Keith Henry, MD reviewing Young J et al. J Acquir Immune Defic Syndr 2015 Apr 28.

Assessment of patients on abacavir in the Swiss Cohort Study found a gradual increase in risk over time.

With today's antiretroviral therapy regimens, HIV-infected patients are surviving to older ages, and cardiovascular disease (CVD) is becoming the most common cause of death. Abacavir, a nucleoside reverse-transcriptase inhibitor that, in combination with 3TC and dolutegravir, is recommended by the Department of Health and Human Services as a first-line therapy, has been linked to an increased risk for CVD in some studies.

Now, investigators have assessed the effect of abacavir on risk for CVD events in the Swiss HIV Cohort Study. Using a new structural Cox model, they estimated this effect as a flexible function of past exposure to the drug, adjusting for CVD risk factors (i.e., hypertension, dyslipidemia, diabetes, renal dysfunction, CD4-cell count, and viral load).

The analysis involved 11,856 patients with a median follow-up of 6.6 years. During this period, 365 of the patients experienced a CVD event (incidence, 4.6/1000 patient-years); 195 of them (53%) had been exposed to abacavir, for a median duration of 3.4 years. With the conventional Cox model, recent but not cumulative exposure to abacavir increased CVD risk. With the new, adjusted Cox model, continued use of abacavir over the preceding 4 years — compared with no use — doubled the risk. Exposure over the preceding 6 to 36 months conferred the greatest increased risk; exposure within the most-recent 6 months had little effect.

Citation(s):

Young J et al. The effect of cumulating exposure to abacavir on the risk of cardiovascular disease events in patients from the Swiss HIV Cohort Study. J Acquir Immune Defic Syndr 2015 Apr 28; [e-pub].