This is an open-label, placebo run-in study to investigate the genetic and biomedical predictors of blood pressure response to bisoprolol. After informed consent is obtained, subjects will be withdrawn from previous antihypertensive therapy and given placebo for at least 2 weeks. Compliance will be assessed using pill counting, and any subject will a compliance less than 80% during the placebo run-in period will be excluded from the study. Bisoprolol 2.5 mg will be given once daily for 6 weeks. At baseline and after 6 weeks on bisoprolol 2.5 mg the clinic sitting blood pressure, 24-hour ambulatory blood pressure (if the patient is willing to do this), clinical characteristics and biochemical profile will be measured. Central aortic blood pressure will be measured with the A-PULSE device at baseline and after 6 weeks treatment.

After completing 6 weeks treatment with bisoprolol 2.5 mg daily, the patient will continue treatment with bisoprolol for a total of 24 weeks unless there is any adverse event that requires discontinuation of bisoprolol.

Patients with uncontrolled essential hypertension aged 18-79 years on no antihypertensive treatment with sitting clinic systolic blood pressure of 140-169 mmHg and/or a sitting clinic diastolic blood pressure of 90-109 mmHg, or for patients with diabetes mellitus or with chronic kidney disease with sitting clinic systolic blood pressure of 130-169 mmHg and / or a sitting clinic diastolic blood pressure of 80-109 mmHg and heart rate > 70 at baseline (before starting bisoprolol treatment) will be enrolled. Patients on other antihypertensive treatments who are experiencing side effects or whose blood pressure may not be well controlled can also enter if they can continue on a stable dose of a calcium channel blocker, either amlodipine or nifedipine retard throughout the study.

Patients will be treated with bisoprolol 2.5mg daily for a total of 26 weeks. The primary endpoint will be the influence of common genetic polymorphisms on clinic sitting blood pressure or ambulatory blood pressure (ABP) response to bisoprolol 2.5 mg after 6 weeks treatment.

Inclusion Criteria:

• Patients with essential hypertension
• For uncomplicated hypertensive patients on no antihypertensive treatment, sitting clinic systolic blood pressure of 140-169 mmHg and / or a sitting clinic diastolic blood pressure of 90-109 mmHg.
• For patients with diabetes mellitus or with chronic kidney disease, sitting clinic systolic blood pressure of 130-169 mmHg and / or a sitting clinic diastolic blood pressure of 80-109 mmHg.
• Patient has a heart rate >70 b/min at baseline (before starting bisoprolol treatment)

Exclusion Criteria:

• Secondary Hypertension
• Pregnant or lactating women and women with childbearing potential not using adequate method of contraception or agreeing to maintain sexual abstinence throughout the study;
• Unstable angina, history of myocardial infarction, stroke or coronary heart disease (coronary by-pass or angioplasty) in the previous 3 months;
• Heart failure (New York Heart Association [NYHA] III-IV);
• Haemodynamically relevant aortic or mitral valve disease;
• Obstructive hypertensive cardiomyopathy;
• Symptomatic bradycardia, second or third degree atrio-ventricular (AV) block, sick sinus syndrome, sinoatrial block, or heart rate <70 b/min at baseline (before starting bisoprolol treatment);
• Primary hyperaldosteronism;
• Renal artery stenosis;
• Impairment of hepatic or renal function as defined by liver function values of ALT ≥1.5-fold the upper normal limit or serum creatinine >150 µmol/L or upon investigator decision;
• History of intolerance to beta-blockers the drug classes used in the study.
• Patients with a known contraindication to beta-blockers, e.g. bradycardia, asthma, severe peripheral vascular disease.