In a comparison of the angiotensin II receptor blockers (ARBs) candesartan and losartan, used by patients with heart failure, candesartan was associated with a lower risk of death at 1 and 5 years, according to a study in the January 12 issue of JAMA.

Angiotensin II receptor blockers reduce cardiovascular mortality and heart failure (HF) hospitalization in patients with HF with reduced left ventricular ejection fraction (LVEF). Despite variable effects of different ARBs, they have not been tested head to head, and there are reasons to believe they may differ in efficacy, according to background information in the article. Previous research found that in elderly patients with HF, losartan was associated with higher mortality than other ARBs.

Maria Eklind-Cervenka, M.D., of the Department of Cardiology, South Hospital, Stockholm, and colleagues conducted a study to determine whether candesartan is associated with less all-cause mortality than losartan in patients with HF. The study included analysis of data from the Swedish Heart Failure Registry of 30,254 patients registered from 62 hospitals and 60 outpatient clinics between 2000 and 2009. A total of 5,139 patients (average age, 74; 39 percent women) were treated with candesartan (n = 2,639) or losartan (n = 2,500).

In overall survival between the 2 groups, the researchers found that one-year survival was 90 percent for patients receiving candesartan and 83 percent for patients receiving losartan, and 5-year survival was 61 percent for patients receiving candesartan and 44 percent for patients receiving losartan. The results persisted in stratified analyses.

The researchers add that there are mechanistic reasons to believe candesartan may be more effective than losartan and that studies of candesartan have been larger and more conclusively positive than studies of losartan.

"In conclusion, our findings suggest that candesartan is associated with less all-cause mortality than losartan. However, clinical decision-making should await supportive evidence of this observed association. Ideally, different ARB agents should be tested against each other in randomized controlled trials. It would also be important and perhaps more feasible to confirm our findings in other large HF registries," the authors write.