This trial is aimed to assess the efficacy and safety of a fixed-dose combination therapy with Valsartan and Chlorthalidone, Vs Valsartan or Chlorthalidone alone for treatment of adult patients with diagnosis of arterial hypertension.

In spite of the existence of a great variety of treatments with drugs effective against arterial hypertension, the percentages of arterial hypertension control with monotherapy remain quite low reason why the fixed-dose combinations of drugs have been one of the most interesting research topics in order to achieve an appropriate control of arterial hypertension.

The possibility of achieving better coverage and Blood Pressure control through a drug combination has leaded, on a scientific base of the efficacy of an Angiotensin Receptor Blockers II plus diuretic combination, to the development of a great number of combinations with different Angiotensin II Receptor Blockers plus hydrochlorothiazide. Yet it is noteworthy that despite the increasing evidence showing additional benefits in Blood pressure control and reduction of cardiovascular outcomes with chlorthalidone over hydrochlorothiazide, there is neither a great number of combinations nor studies with Angiotensin II Receptor Blockers plus chlorthalidone whereby the conduction of a trial assessing the efficacy and safety of Valsartan plus chlorthalidone in hypertensive patients is proposed plus the benefits of combination therapy that include, among others, the greater efficacy with lower doses of each individual component as well as reduction in occurrence of adverse events directly related with lower drug doses.With this treatment schedule it is expected to obtain higher control of blood pressure values and greater percentage of patients.

Inclusion Criteria:

• Patient with diagnosis of arterial hypertension defined as:
• Systolic blood pressure greater or equal to 140 and lower than 180 mmHg
• Diastolic blood pressure greater or equal to 90 and lower than 110 mmHg
• Non controlled patients with antihypertensive treatment (blood pressure values: Systolic blood pressure > 140 mmHg and/or Diastolic blood pressure > 90 mmHg) or patients antihypertensive treatment-naïve.
• Likelihood of attending consultations according to the trial chronogram.
• Informed Consent Signature.

Exclusion Criteria:

• Diagnosis of severe or malignant arterial hypertension defined as:
• Systolic blood pressure greater or equal to 180 mmHg
• Diastolic blood pressure greater or equal to 110 mmHg
• Patients with secondary arterial hypertension of any etiology.
• Pregnant women or women with childbearing potential who are not using appropriate contraception methods; women planning to become pregnant during the trial.
• Patients with history of Acute Myocardial Infarction o Angina Pectoris within the 6 months prior to the trial initiation.
• Diagnosis of Cerebrovascular Disease (CVD) o Transient Ischemic Attack (TIA) within the 6 previous months.
• Patients with Severe Renal Disease defined by serum Creatinine levels higher than 1.5 mg/dl.
• Diagnosed or suspected unilateral or bilateral renal artery stenosis.
• History of non remitting cancer within the 5 years prior to the trial initiation.
• Patients with Hypokalemia or Hyperkalemia.
• Patients receiving Valsartan or Chlortalidone during the 14 previous days.
• Patients with known hypersensitivity to Valsartan or Chlorthalidone.
• Unstable patients with antecedent of hospitalization within the 4 days prior to their enrollment in the trial.
• Patients with history of drugs and alcohol abuse within the last year.
• Patients who have taken part in other clinical trial within the 4 weeks prior to the initiation of this research.
• Patients with any other clinical condition that the investigator deems may affect the patient follow-up.