Note: Initiation or adjustment of antihypertensive medication(s) is permitted during the screening period, in order to control a patient's BP prior to randomization. Blood pressure must be re-assessed on two occasions that are separated by a minimum of 1 hour. The mean SBP / DBP values from each blood pressure assessment must be < 140/90mmHg in order for a patient to be eligible for the study. See Section 6.2 and Section 6.4.2 for details on blood pressure control and reassessment prior to study enrollment.