A large bowl brimming with fruit holds pride of place
on the kitchen table in 56-year-old Josh M's suburban
Saskatoon home. Once that bowl would have been filled
with chips and cheesies, but a heart disease diagnosis
five years ago forced Josh to turn his life around. Like
many in his position, Josh changed his diet and started
exercising regularly — and managed to lighten up
to the tune of 20kg, bring his cholesterol under control
and lower his once sky-high blood pressure (BP) to near
normal. He figures he's on the road to cardiac salvation,
but it may be wise to consider the outcome of an international
study on hypertension before he cancels his life insurance
policy. Despite what the latest Canadian hypertension
guidelines say Josh and others like him may benefit from
a further nudge down in BP.
PUSH
THE LOWER LIMIT
The latest hypertension guidelines were released in
January by the Canadian Hypertension Education Program
- an organization that meets annually to update evidence-based
recommendations for the management of hypertension.
This year, the revised guidelines push the hypertension
alert down from the previous Canadian benchmark of 140/90mmHg
for the general population and 130/80mmHg for folks
with diabetes or renal disease. Optimal BP according
to Canadian and European guidelines is set at 120/80mmHg.
Yet folks like Josh might want
to take their BP down even lower. The suggested amendment
comes courtesy of an international trial known by its
lofty acronym CAMELOT (Comparison of Amlodipine versus
Enalapril to Limit Occurrences of Thrombosis). Results
of the CAMELOT study can be found in the November 10,
2004 issue of Journal of the American Medical Association.
The US guidelines for hypertension, which sets a cutoff
for healthy BP at 115/78mmHg was based on the outcome
of this trial and may in fact be a healthier mark to
aim for.
The 2,000 CAMELOT participants
all had heart disease and an average BP of 129/78mmHg
- a reading that would pass muster as normal in doctor's
offices everywhere. Folks were assigned to receive either
the calcium channel blocker amlodipine, the ACE inhibitor
enalapril, or a placebo.
THE
DRUG ADVANTAGE
The drugs lowered BP and the group that received them
fared better in the two years of followup, in terms
of death from cardiovascular disease, having a nonfatal
heart attack or stroke, having heart bypass surgery
or surgery to repair arteries, or being hospitalized
for chest pain.
The drug advantage was not huge
- 23% of the placebo crowd had cardiovascular problems,
compared to 17% in the amlodipine group and 20% in the
enalapril group. But, considering that millions of people
have heart disease but normal BP, the findings indicate
that thousands of lives could be saved and many surgical
procedures avoided just by getting BP down a little
more.
The bottom line is that while
drug therapy has its place, the good-for-you lifestyle
modifications exemplified by Josh "are the cornerstone
of both antihypertensive and antiatherosclerotic therapy,"
according to the Canadian Hypertension Education Program.
But lowering even BP that's deemed "normal" by current
Canadian standards may push down the risk of a heart
attack, stroke, severe chest pain or the need to unclog
coronary arteries, providing folks like Josh with a
further advantage.
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