Meta-analysis of observed mortality data from all-controlled, double-blind, multiple-dose studies of losartan in heart failure

Clinical studies of heart failure utilizing losartan, an angiotensin-II receptor antagonist, found that this drug is well tolerated and demonstrates hemodynamic, neurohormonal, and symptomatic improvement. To assess all-cause mortality in heart failure patients treated with losartan, a meta-analysis including 1,896 patients was performed on 6 controlled, double-blind, multiple-dose studies, regardless of sample size or duration of follow-up. A combination of logarithmic (log) odds ratios with a continuity correction was utilized for the meta-analysis. Treatment groups were comparable with regard to demographic characteristics, heart failure characteristics, and concomitant cardiovascular therapies. Concomitant use of open-label angiotensin-converting enzyme (ACE) inhibitors was not allowed in any study. The mean left ventricular ejection fraction obtained in individual studies ranged from 23% to 31%. Seven hundred forty patients were randomized to control therapy and 1,154 patients were randomized to losartan therapy. There were 36 deaths (3.12%) in the losartan groups compared with 47 in the control groups (6.35%) during the double-blind periods. The odds of dying in the losartan groups were 0.51 times (0.31 to 0.81) that of dying in the control groups (p = 0.004). In this analysis, treatment with losartan provided a beneficial effect upon survival. However, because the number of deaths in these studies is relatively small and the follow-up relatively short, a large confirmatory study is needed to assess the mortality benefit of losartan compared with an ACE inhibitor.