All concepts, explanations, trials, and studies have been
re-written in plain English and may contain errors. I am
not a doctor
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Systolic Blood Pressure and Mortality

Experts all agree there is a relationship between high
systolic blood pressure and increased risk of mortality.
This risk is though to become unacceptable at 140 mm Hg,
so therapy should be started when systolic BP reaches
140, regardless of patient age or sex.
	This concept has now been challenged by a group
of statisticians. They constructed a mathematical model
using data from the Framingham Study.
	They arranged systolic pressure by 10% groupings,
age groups (45 to 54 years, 55 to 64 years, and 65 to 74
years), and patient sex.
	They used death as the end point, not stroke or
heart attack. This more complicated model showed no
increase in risk for death up to at least the 7th 10%
grouping of systolic blood pressure, an increase in risk
of death between the 7th and 8th 10% grouping, and a
steep increase in risk after that.
	This analysis considered both age and sex. Elderly
women tolerated higher systolic pressures than younger men.
Using this model - when men were compared against women -
it was seen that high blood pressure did not need
treatment until systolic pressure was:

1) over 159 mm Hg in men and 167 mm Hg in women
   aged 65 to 74.
2) over 148 mm Hg in men and 158 mm Hg in women
   aged 55 to 64.
3) over 141 mm Hg in men and 142 mm Hg in women
   aged 45 to 54.

The authors say that although systolic blood pressure is
important, starting treatment at a systolic pressure of
140 mm Hg is not justified.

Title: Systolic blood pressure and mortality.
Authors: Port S, Demur L, Jennrich R, et al.
Source: Lancet. 2000;355:175-180.

COMMENT:
We always hear how poorly blood pressure is being controlled
and the most recent guidelines say we should reduce systolic
blood pressure to 140 mm Hg or lower.
	Along comes this mathematical analysis suggesting
that we are unnecessarily treating many patients. If accepted,
this would have a major impact on how many elderly patients
are treated for systolic high blood pressure.
	This is the first time most doctors have seen the
logistic spline model, which is new so it lacks clinical
evidence of support and possibly biologic sense as well.
	The statisticians ignored stroke and heart attack in
their analysis and only measured mortality because it was
"free of misclassification." The problem we all face as
doctors however, is that our patients benefit from preventing
stroke and other heart-related events and not just from
preventing death.
	If we accept that we should reduce systolic pressure
to 155 mm Hg in men and 167 mm Hg in women from 65 to 74
years old, we ignore SHEP (not the stooge - the Systolic
Hypertension in the Elderly). SHEP showed a large reduction
in stroke heart-related events with systolic blood pressure
reduction to 143 mm Hg as opposed to 155 mm Hg in placebo
patients.
	Decisions about a treatment's usefulness should be
based on clinical trials which study both complications and
symptoms, as well as mortality. We should continue to use
current guidelines for treating high blood pressure.
	For now, we should reduce systolic blood pressure to
less than 140 mm Hg and watch for new trials that address
the issue raised by this study.