5 Is one treatment for hypertension proven to be
better than another in terms of survival?
Kieran Bhagat
In terms of efficacy, there is no evidence that any one class of anti-
hypertensive is superior to another at standard doses used as
monotherapy. All agents reduce blood pressure by a similar
amount (approximately 5–10mmHg). However, if one assesses
the large outcome trials (in terms of survival) then only the
diuretics are well supported in showing reduction in mortality.
The beta blockers have nnoottbeen shown to reduce mortality. The
oft-quoted MRC trial in elderly people used atenolol and did not
reduce mortality when compared to placebo.^1 Indeed, cardio-
vascular mortality seemed to increase in the atenolol group. In the
Swedish trial in elderly patients with hypertension,^2 in which
mortality was reduced, initial beta blockade was one of the arms
of treatment, but over two thirds of patients received an added
diuretic. (If the proposal is that combined treatment with beta
blockade and diuretic can reduce mortality then there are indirect
supporting data from the Swedish trial.) In the MRC trial in
middle-aged people, propranolol had only modest effects in non-
smokers and conferred little or no benefit in smokers. Mortality
was not decreased, and the trial was not powered for mortality.
Nonetheless it can be convincingly argued that end points such as
reduction in stroke are important and that the beta blockers have
been shown to reduce the incidence of neurovascular events in
several trials. By contrast there is already one good outcome study
with a calcium blocker^3 but no outcome studies in essential
hypertension in the elderly with ACE inhibitors, nor are there
any in younger age groups. In spite of the above there still remain
compelling reasons to prescribe a certain class of antihypertensive
agent in patients that may have additional problems. For
example, one might prescribe an ACE inhibitor to those with type
1 diabetes with proteinuria, or those with hypertension and heart
failure. Similarly it might be equally cogent to prescribe a calcium
antagonist in systolic hypertension in the elderly.
RReeffeerreenncceess
1 MRC Working Party. Medical Research Council trial of treatment of
hypertension in older adults: principal results. BMJ1992; 330044 : 405–12.