Very difficult to recruit patients/slow recruitment(2 patients in nearly 2 years).

The purpose of this study is to compare the impact of two blood pressure lowering treatments (high dose quinapril versus low dose quinapril plus amlodipine) on variations in heart rate over 24 hours.

Inclusion Criteria:

• Patients with a documented history of hypertension defined as: SBP > or = 140 mmHg or DBP > or = 90 mmHg if hypertension untreated or patients currently treated for hypertension.
• Documented CAD or diabetes or impaired glucose tolerance
• Sinus rhythm

Principal Exclusion Criteria:

• Previous intolerance or allergic reaction to an ACE inhibitor, an ARB or dihydropyridine calcium channel blocker
• History of angioedema or cough related to previous ACE inhibitor use.
• Systolic blood pressure > 180 mmHg or diastolic blood pressure > 110 mmHg in untreated patients
• Systolic blood pressure > 160 mmHg or diastolic blood pressure > 100 mmHg in patients currently treated by an ACE inhibitor or an ARB
• Creatinine clearance < 30 ml/min
• Significant liver dysfunction
• Current serum potassium > or = 5 mmol/L or a history of marked ACE inhibitor or ARB induced hyperkalemia resulting in either a serum potassium > or = 5.5 mmol/L or a life-threatening adverse event.
• History of HF or known LVEF < or = 45%
• Bilateral renal artery stenosis (or unilateral if only one kidney)
• Unstable angina, myocardial infarction or coronary revascularization within the last 3 months.
• Connective tissue disease or chronic inflammatory condition
• Active malignancy
• Active infection in the last 2 weeks
• Inability or any contraindication to perform an exercise test.