Second-Line HIV Therapy Outcomes and Determinants of Mortality at the Largest HIV Referral Center in Southern Vietnam

Abstract

The growing numbers of HIV-infected patients requiring second-line antiretroviral therapy (ART) in Vietnam make essential the evaluation of treatment efficacy to guide treatment strategies.We evaluated all patients aged ≥15 years who initiated second-line ART after documented failure of first-line therapy at the Hospital for Tropical Diseases in Ho Chi Minh City. The primary outcome was time from second-line ART initiation to death, or to a new or reoccurrence of a WHO-defined immunological or clinical failure event, whichever occurred first. Risks of treatment failure and death were evaluated using Cox proportional hazards modeling.Data from 326 of 373 patients initiating second-line ART between November 2006 and August 2011 were included in this analysis. The median age was 32 years (IQR: 28-36). Eighty one percent were men. The median CD4 count was 44 cells/μL (IQR: 16-84). During a median follow-up of 29 months (IQR: 15-44), 60 (18.4%) patients experienced treatment failure, including 12 immunological failures, 4 WHO stage IV AIDS events, and 44 deaths (13.5%). Sixty percent of deaths occurred during the first 6-12 months. The Kaplan-Meier estimates of treatment failure after 1, 2, 3, and 4 years were 13.1% (95% CI: 9.2-16.8), 18.6% (95% CI: 14.0-23.1), 20.4% (95% CI: 15.4-25.1), and 22.8% (95% CI: 17.2-28.1), respectively. Older age, history of injection drug use, lower CD4 count, medication adherence <95%, and previous protease inhibitor use independently predicted treatment failure.While treatment efficacy was similar to that reported from other resource-limited settings, mortality was higher. Early deaths may be averted by prioritizing second-line therapy for those with lower CD4 counts and by improving treatment adherence support.

FIGURE 1

Flowchart of study population and outcome events.

FIGURE 2

The cummulative incidence of treatment failure on second-line antiretroviral therapy over time. A, Treatment failure in all patients in the cohort. The dotted lines represent the point-wise 95% confidence interval. B, Treatment failure in patients with and without history of injection drug use. C, Treatment failure in patients with suboptimal and optimal antiretroviral adherence. D, Treatment failure in patients with previous and no protease inhibitor exposure.