CR Aim #2 - AT1 Receptor Blockade & ACE Inhibition Effect on Humoral Function

Inclusion Criteria: * Left ventricular ejection fraction of equal or less than 40% assessed by echocardiography, nuclear scan, MRI or left ventriculogram within the past 48 months. * Stable New York Heart Association (NYHA) class II and III symptoms as defined by: no change in NYHA symptoms over the past 3 months, on stable doses of ACE inhibitor, beta blocker, digoxin and furosemide over the last 4 weeks and no episode of decompensated CHF over the past 6 months. * Calculated creatinine clearance of equal or less than 80 ml/min and greater than 20 ml/min, using the MDRD formula assessed within the past 48 months and a confirmatory calculated creatinine clearance equal or less than 80 ml/min and greater than 20 ml/min at the time of enrollment. Subjects who are already taking AT1 receptor blocker will be excluded. Aldosterone antagonist, antiarrhythmic medications and other vasodilators will be allowed; however, all medications must be at stable doses 4 weeks prior to enrollment. Subjects taking nonsteroidal anti-inflammatory drugs (NSAIDs) except aspirin will not be able to increase their medication dose for the duration of the study. Subjects will be excluded if they have had a prior diagnosis of intrinsic renal disease, including renal artery stenosis of \> 50%, or if they meet any one of the exclusion criteria listed below. Exclusion Criteria: * Prior diagnosis of intrinsic renal diseases including renal artery stenosis of \> 50% * Peritoneal or hemodialysis within 90…