A Pharmacogenomic Study of Candesartan in Heart Failure

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.