Session 35aOral Abstract Presentations Clinical Trials and Cohorts Session Day and Time: Friday 8:30 - 10:30 am Presentation Time: 10:00 Room: Auditorium
182 The Impact of Baseline Plasma HIV RNA and Adherence on Response to Therapy and Mortality After the Initiation of HAART E Wood*, R S Hogg, B Yip, R Quercia, P R Harrigan, M V O'Shaughnessy, J S Montaner British Columbia Ctr for Excellence in HIV/AIDS, Vancouver, Canada
Background: Emerging evidence suggests that patients (pts) with baseline plasma HIV-1 RNA levels > 100,000 copies/mL may be at increased risk of death after the initiation of HAART. The mechanism responsible for this association is not known. We therefore evaluated if the association between baseline HIV RNA and mortality may be explained by incomplete adherence or virological response to HAART.
Methods: Population-based analysis of 1,420 antiretroviral na´ve HIV-infected pts who initiated triple therapy between August 1, 1996, and July 31, 2000, and who were followed until March 31, 2002. Pts who received medications > 95% of the time during the first year of HAART were defined as adherent. We evaluated rates of HIV-related mortality and virological suppression among pts stratified into baseline HIV RNA groupings: < 50,000, 50-99,999, and > 100,000 copies/mL, respectively. Cox regression was used to determine independent predictors of time to death and HIV RNA suppression. We also fit a logistic model to evaluate the likelihood of ever achieving suppression during follow-up.
Results: In a multivariate model that adjusted for adherence (Adjusted Relative Hazard [ARH]: 0.35 [95% CI: 0.25-0.49]), baseline HIV RNA > 100,000 remained independently associated with HIV-related mortality (ARH: 1.81 [95% CI: 1.15-2.84]). With regards to a possible mechanism, when we evaluated if differences existed among adherent pts, we observed that adherent pts with baseline HIV RNA > 100,000 copies/mL had a slower rate of HIV RNA suppression and were significantly less likely to ever achieve suppression during the entire follow-up (Adjusted Odds Ratio [AOR]: 0.27 [95% CI: 0.13-0.53]) in comparison to adherent pts with baseline HIV RNA < 50,000. For both mortality and suppression, there was no difference between the < 50,000 and 50-99,999 HIV RNA strata.
Conclusions: After adjustment for adherence, baseline HIV RNA > 100,000 remained independently associated with mortality. We also found that adherent pts with baseline HIV RNA > 100,000 were slower to suppress and were significantly less likely to ever suppress HIV RNA than those in the lower baseline HIV RNA strata and when the entire follow-up period was considered. If these findings can be independently confirmed, they may have implications for the development of therapeutic guidelines for pts with baseline HIV RNA > 100,000 copies/mL.