Context: The benefit of angiotensin II-receptor blockers (ARBs) in heart failure is thought to be a class effect, but no head-to-head randomized trials have compared individual ARBs. Results from observational studies suggest that losartan may be associated with increased mortality in patients with heart failure compared with other ARBs.
Objective: To assess the hypothesis that losartan use is associated with increased all-cause mortality in heart failure patients as compared with candesartan.
Design, setting, and participants: We conducted a nationwide Danish registry-based cohort study, linking individual-level information on hospital contacts, filled prescriptions, and potential confounders. Patients aged 45 years and older with first-time hospitalization for heart failure in 1998-2008 were identified from the Danish National Patient Registry. New users of losartan and candesartan were selected for inclusion in the study cohort.
Main outcome measures: We used Cox proportional hazards regression to compare the risk of all-cause mortality in users of losartan and candesartan.
Results: Among 4397 users of losartan, 1212 deaths occurred during 11,347 person-years of follow-up (unadjusted incidence rate [IR]/100 person-years, 10.7; 95% CI, 10.1-11.3) compared with 330 deaths during 3675 person-years among 2082 users of candesartan (unadjusted IR/100 person-years, 9.0; 95% CI, 8.1-10.0). Compared with candesartan, losartan was not associated with increased all-cause mortality (adjusted hazard ratio [HR], 1.10; 95% CI, 0.96-1.25) or cardiovascular mortality (adjusted HR, 1.14; 95% CI, 0.96-1.36). Compared with high doses of candesartan (16-32 mg), low-dose (12.5 mg) and medium-dose losartan (50 mg) were associated with increased mortality (HR, 2.79; 95% CI, 2.19-3.55 and HR, 1.39; 95% CI, 1.11-1.73, respectively); use of high-dose losartan (100 mg) was similar in risk (HR, 0.71; 95% CI, 0.50-1.00).
Conclusions: Among patients with heart failure, overall use of losartan compared with candesartan was not associated with an increased mortality risk. Although low doses of losartan were associated with increased mortality, there was no increased mortality comparing high-dose losartan against the highest doses of candesartan.