Abstract
A double-blind randomised placebo-controlled trial of antihypertensive treatment was conducted in patients over the age of 60. Entry criteria included both a sitting diastolic blood pressure on placebo treatment in the range 90-119 mm Hg and a systolic pressure in the range 160-239 mm Hg. 840 patients were randomised either to active treatment (hydrochlorothiazide + triamterene) or to matching placebo. If the blood pressure remained raised, methyldopa was added to the active regimen and matching placebo in the placebo group. An overall intention-to-treat analysis, combining the double-blind part of the trial and all subsequent follow-up, revealed a non-significant change in total mortality rate (-9%, p = 0.41) but a significant reduction in cardiovascular mortality rate (-27%, p = 0.037). The latter was due to a reduction in cardiac mortality (-38%, p = 0.036) and a non-significant decrease in cerebrovascular mortality (-32%, p = 0.16). In the double-blind part of the trial, total mortality rate was not significantly reduced (-26%, p = 0.077). Cardiovascular mortality was reduced in the actively treated group (-38%, p = 0.023), owing to a reduction in cardiac deaths (-47%, p = 0.048) and a non-significant decrease in cerebrovascular mortality (-43%, p = 0.15). Deaths from myocardial infarction were reduced (-60%, p = 0.043). Study-terminating morbid cardiovascular events were significantly reduced by active treatment (-60%, p = 0.0064). Non-terminating cerebrovascular events were reduced (-52%, p = 0.026), but the non-terminating cardiac events were not (+3%, p = 0.98). In the patients randomised to active treatment there were 29 fewer cardiovascular events and 14 fewer cardiovascular deaths per 1000 patient years during the double-blind part of the trial.