Olmesartan Comparison to Losartan in Hypertensive Subjects

Inclusion Criteria: * Males or females aged \> 18 years who are not institutionalized and have signed informed consent. * Mean cuff seated diastolic blood pressure (BP) must be \> 95 mmHg and \< 115 mmHg and a mean cuff seated systolic BP must be \< 180 mmHg when measured at two consecutive qualification study visits during the placebo run-in phase. * The difference in mean cuff seated diastolic BP must be \< 7 mmHg between two consecutive qualification study visits during the placebo run-in phase. Exclusion Criteria: * Subjects with type 2 diabetes mellitus with an HbA1c ≥ 9.5% at Screening. * Subjects with serious disorders which may limit the ability to evaluate the efficacy or safety of olmesartan medoxomil and losartan potassium, including cardiovascular, renal (including the absence of one kidney), pulmonary, hepatic, gastrointestinal (including clinically significant malabsorption), endocrine/metabolic (with the exception of non-insulin, dependent type 2 diabetes mellitus with HbA1c \< 9.5% at Screening), hematologic/oncologic (including an active malignancy other than basal cell carcinoma), neurologic and psychiatric diseases. * Subjects with a history of myocardial infarction, angina, coronary angioplasty, bypass surgery or heart failure within the last 12 months. * Subjects with any history of New York Heart Association Class III or IV congestive heart failure (CHF). A history of New York Heart Association Class I or II CHF may be exclusionary at the discretion of the Investigator. * Subjects with a history of cerebrovascular accident or transient ischemic attack within the last 1 year. * Subjects with clinically significant cardiac conduction defects, including second or third degree atrioventricular (AV) block, left bundle branch block, sick sinus syndrome, atrial fibrillation, atrial flutter, an accessory bypass tract, or any arrhythmia requiring medication.