Long-term clinical and economic outcomes associated with angiotensin II receptor blocker use in hypertensive patients.

OBJECTIVE

To examine clinical and economic outcomes associated with angiotensin II receptor blockers (ARB).

METHODS

Retrospective claims data were analyzed for hypertensive adults with ≥1 year follow-up from first ARB claim. Subjects were stratified into four cohorts: olmesartan (OM); valsartan (VAL); losartan (LOS); and irbesartan (IRB), which represented the full sample. Analyses were also conducted with the "limited sample," which excluded subjects with pre-existing conditions in the period before first ARB. Time to follow-up cardiac event was modeled using Cox proportional hazards regression; follow-up healthcare resource utilization and costs were examined using generalized linear models.

RESULTS

The full and limited samples consisted of 118,700 and 65,579 subjects, respectively. Mean follow-up ranged from 861 to 933 days. Baseline characteristics including the Quan-Charlson comorbidity score differed by cohort. In both the full and limited samples, respectively, multivariate models predicted a higher adjusted risk of follow-up cardiac event for VAL cohort (hazard ratio [HR] = 1.261 and 1.242, p < 0.001), LOS cohort (HR = 1.307 and 1.178, p < 0.01), and IRB cohort (HR = 1.222 and 1.179, p ≤ 0.016) compared to OM cohort. Adjusted risk (full sample) of follow-up ambulatory and inpatient visits (all-cause and hypertension-attributable) was higher in VAL, LOS, and IRB cohorts compared to OM. Adjusted risk (limited sample) of follow-up ambulatory visits (all-cause and hypertension-attributable) was greater for VAL, LOS and IRB cohorts relative to OM, but inpatient visit risk was greater only in VAL and LOS cohorts. Compared to the OM cohort, follow-up all-cause adjusted healthcare costs (limited sample) were higher in VAL (cost ratio [CR] = 1.067, p = 0.001) and IRB cohorts (CR = 1.062, p = 0.045).

CONCLUSIONS

In this large national US health plan, treatment with OM was associated with lower risk of cardiac events and lower healthcare resource utilization and costs versus VAL, LOS, and IRB over a mean follow-up of 2.5 years. Association, rather than causality, to cardiac outcomes may be inferred from these observational claims data.