The Effects of Moderate vs. Aggressive Treatment With Valsartan + Amlodipine on Patients With Hypertension Uncontrolled by Angiotensin-Receptor Blocker (Herein, ARB) Monotherapy

Inclusion Criteria: * Male and female outpatients * 18 Years of age or older * Mean Sitting Systolic Blood Pressure (the top number) greater than or equal to 150 mmHg and lower than 200 mmHg while on Angiotensin-Receptor Blocker monotherapy for a minimum period of 28 days prior to randomization Exclusion Criteria: * Mean Sitting Systolic Blood Pressure (the top number) greater than or equal to 200 mmHg and/or Mean Sitting Diastolic Blood Pressure greater than or equal to 120 mmHg * Transient ischemic attack (mini-stroke), myocardial infarction (heart attack), all types of revascularization procedures in the last 6 months * Treatment with valsartan or any combination antihypertensive treatment with 28 days prior to screening (Visit 1)