Angiotensin II receptor blockers for the treatment of heart failure: a class effect?

STUDY OBJECTIVE

To examine the class effect of angiotensin II receptor blockers (ARBs) on mortality in patients with heart failure who were aged 65 years or older.

DESIGN

Retrospective population-based study.

DATA SOURCE

Administrative database that stores information on hospital discharge summaries for the Canadian provinces of Quebec, Ontario, and British Columbia.

PATIENTS

A total of 6876 patients aged 65 years or older who were discharged with a primary diagnosis of heart failure between January 1, 1998, and March 31, 2003, and who filled at least one prescription for an ARB within 90 days of discharge.

MEASUREMENTS AND MAIN RESULTS

Times to all-cause death in patients receiving individual ARBs were compared. Models were adjusted for demographic, clinical, physician, and hospital characteristics; models were also adjusted for dosage categories, which were represented by time-dependent variables. The cohort of 6876 patients had a mean +/- SD age of 78 +/- 7 years, and most (62%) were women. Losartan was the most frequently prescribed ARB (61%), followed by irbesartan (14%), valsartan (13%), candesartan (10%), and telmisartan (2%). Irbesartan, valsartan, and candesartan were associated with better survival rates than losartan (adjusted hazard ratios [HRs] and 95% confidence intervals [CIs] 0.65 [0.53-0.79], 0.63 [0.51-0.79], and 0.71 [0.57-0.90], respectively). No difference was noted in mortality in patients prescribed telmisartan compared with those receiving losartan (HR 0.92 [95% CI 0.55-1.54]).

CONCLUSIONS

Elderly patients with heart failure who were prescribed losartan had worse survival rates compared with those prescribed other commonly used ARBs. The absence of a class effect for ARBs is consistent with data showing pharmacologic differences among the drugs.