By: Thomas Pickering, MD, DPhil, FRCP, Director of Integrative and Behavioral Cardiology Program
of the Cardiovascular Institute at Mount Sinai School of Medicine, New York.

One of the big questions concerning the treatment of hypertension is whether the newer drugs such as ACE inhibitors and calcium channel blockers give the same degree of protection against strokes and heart attacks as the older drugs such as beta blockers and diuretics, which have been used in almost all of the studies which have shown that treating hypertension does reduce these risks.

A new study which has examined this question is the Swedish Trial in Old Patients with hypertension-2 (STOP-2). A group of 6,614 patients aged 70 to 84 with blood pressures of at least 180/105 mmHg were enrolled, and divided into three treatment groups: first, beta blockers and diuretics (the physicians could choose between three beta blockers and two diuretics); second, ACE inhibitors (enalapril or lisinopril); and third, calcium channel blockers (felodipine or isradipine). The goal of the study was to see if the groups differed in the numbers of deaths, strokes, and heart attacks over a five-year period.

The reduction of blood pressure was the same in all three groups (about 34 mmHg systolic, and 17 mmHg diastolic pressure). The main finding was that the mortality rates, and the numbers of strokes and heart attacks, were the same for all three treatment groups; thus the “newer” drugs (ACE inhibitors and calcium channel blockers) did not show any overall superiority to the “older” drugs (beta blockers and diuretics), and they also did not cause any less side effects.

When the ACE inhibitors were compared against the calcium channel blockers there were two differences which were significant: patients taking ACE inhibitors were 20% less likely to have a heart attack or to develop heart failure than patients taking calcium channel blockers.

In this study, unlike some others, ACE inhibitors did not appear to prevent the onset of diabetes.

Doctor’s comments

This is an important study and is the first in which the two newer classes of drugs- ACE inhibitors and calcium channel blockers, have been compared directly with diuretics and beta blockers for their effects on mortality in older people with uncomplicated hypertension. The results suggest that the most important thing is the reduction of blood pressure- not which drug is used to lower it. The finding that ACE inhibitors were slightly better than calcium channel blockers in preventing heart attacks and heart failure is in keeping with other studies, although this study did not show that calcium channel blockers are harmful, as was suggested a few years ago.

Where it was published