Principal Inclusion Criteria:

1. Male or female > or = 18 years old.
2. Symptomatic CHF corresponding to NYHA class II-IV symptoms for at least 4 weeks prior randomization.
3. LVEF < or = 40%
4. Treatment with an optimal and stable dose of ACE inhibitor for at least 4 weeks prior to enrolment in the study.

Principal Exclusion Criteria:

1. Treatment with an ARB within 8 weeks prior to randomization.
2. Known hypersensitivity to ARBs or ACE inhibitors.
3. Creatinine clearance < 30 ml/min or serum creatinine > 221
4. Current serum potassium > or = 5.0 mmol/L or a history of marked ACE inhibitor or ARB induced hyperkalemia.
5. Known bilateral renal artery stenosis.
6. Current symptomatic hypotension and/or systolic B.P. < 90 mmHg.
7. Decompensated heart failure described as hospitalization or I.V. administration of medication in emergency room or heart failure clinic within 4 weeks
8. Stroke, acute coronary syndrome, PCI within the last 4 weeks before randomization.
9. Connective tissue disease or chronic inflammatory condition
10. Acute inflammatory process such as an infection or gout attack in the last 2 weeks.
11. Pregnant or lactating women or women of childbearing potential who are not protected from pregnancy by an accepted method of contraception.