Subjects will be transfused at a set transfusion threshold of hemoglobin of 7.0g/dL or below and corresponding hematocrit of 21 or below. Subjects with Hb 7.0g/dL and are symptomatic as evidenced by tachycardia, hypotension, orthostatic hypotension or have pre-existing cardiac or pulmonary disease will also be transfused.