Principal Findings:

The study was stopped early on the advice of the external Safety and Efficacy Monitoring Committee because of an adverse trend in the combination of mortality plus heart failure hospitalization in the candesartan alone group. In the final analysis, there was no difference with regard to these outcomes between the groups. There were no differences among groups with regard to 6-minute walk distance, NYHA-FC, or QOL. EF increased (P=NS) more with candesartan-plus-enalapril therapy (2.5%) than with candesartan alone (1.5%) or enalapril alone(1.5%). End-diastolic (EDV) and end-systolic (ESV) volumes increased less with combination therapy (EDV 8 mL, ESV 1 mL) than with candesartan alone (EDV 27 mL, ESV 18 mL) or enalapril alone (EDV 23 mL, ESV 14 mL) (p<0.01). Blood pressure decreased with combination therapy (6±1/4±1 mm Hg) compared with candesartan or enalapril alone (p<0.05). Aldosterone decreased (p<0.05) with combination therapy (23.2 pg/mL) at 17 weeks compared with candesartan (0.7 pg/mL) or enalapril (-0.8 pg/mL). There were no differences in aldosterone at 43 weeks. BNP decreased with combination therapy (5.8 pmol/L) compared with candesartan (4.4 pmol/L) and enalapril alone (4.0 pmol/L) (p<0.01).