The purpose of the study is to evaluate the blood pressure lowering effect and safety of aliskiren in combination with Hydrochlorothiazide (HCTZ) compared to aliskiren monotherapy when given to metabolic syndrome patients with stage 2 systolic hypertension (mean sitting systolic blood pressure [msSBP] ≥ 160 mm Hg and < 200 mm Hg).

Inclusion Criteria:

• Patients who are eligible and able to participate in the study, and who give written informed consent before any assessment is performed.

• Male or female outpatients ≥ 18 years old.

• Patients with stage 2 systolic hypertension. Patients must have a msSBP ≥160 mmHg and <200 mmHg at Study Visit 5 (randomization).

• Patients who have stage 2 systolic hypertension that meet at least 2 additional components of the metabolic syndrome as defined by the National *Cholesterol Education program (NCEP) criteria:

  • Abdominal obesity (waist circumference > than 102 cm for men and > 88 cm for women)
  • Current triglycerides ≥ 150 mg/dL or medical treatment for this condition.
  • Current HDL- Cholesterol <40 mg/dL in men and <50 mg/dL in women or medical treatment for this condition.
  • Fasting glucose >100 mg/dL and <126 mg/dL

Exclusion Criteria:

• Office blood pressure measured by cuff (msDBP ≥ 110 mmHg and or msSBP ≥ 200 mmHg) at any visit.
• Use of other investigational drugs at the time of enrollment, or within 30 days or 5 half-lives of enrollment, whichever is longer.
• Use of aliskiren and/or a fixed dose combination of aliskiren HCTZ or participation in a clinical trial that had aliskiren and/or aliskiren HCTZ as treatment within 30 days of Visit 1.
• History of hypersensitivity to any of the medications or to drugs belonging to a similar therapeutic class (diuretics or renin inhibitors) as the study drugs.
• History or evidence of secondary form of hypertension.
• Refractory hypertension, defined as unresponsive to triple drug therapy at the maximum dose of each drug, one of which must be a diuretic, and not at blood pressure goal (140/90mmHg). Therapy with a fixed dose combination of two active substances represent two drugs.
• Patients on 4 or more antihypertensive medications.