HYVET is a randomised, double-blind, placebo-controlled trial in hypertensive subjects aged 80 or older. Active treatment consists of indapamide 1.5mg SR with the addition of perindopril 2mg - 4mg to reach a target blood pressure (BP) of <150/80 mmHg. Entry criteria include a systolic blood pressure of 160-199 mmHg. Patients with isolated systolic hypertension (ISH) have been recruited since August 2003.