HYPOTHESES
Left
AND
Main
PROVOCATIONS
Equivalent
Disease:
An Unproven
Hypothesis*
Henry
s
DeMots,
M.D.;#{176}#{176}
and Shahbudin
everal
studies
performed
coronary
artery
bypass
that
the
prognosis
to the
survival
no longer
to
apply
provements
ciple
of
current
function
that
group
of
disease,
patients
to be
adversely
affects
patients
who
with
particular
with
have
three
left
left
most
The
and
clinical
results
in-
The
coronary
major
branches,
“left
main
it has
this designation
principles
derived
main
coronary
patients
with
scending
and
The
been
validity
is that
from
artery
risks
of
disease
may
of this
designation
lar practical
importance
tion of enhanced
survival
coronary
artery
disease
some
implication
left
coronary
becomes
the
Section
of Cardiology,
Portland
tion Hospital,
Portland.
* #{176}Associate Professor
of Medicine.
fProfessor
of Medicine.
Reprint
requests:
Dr. Rahimtoola,
Park
588
Road,
Portland,
Oregon
DE MaTS, RAHIMTOOLA
97201
“left
tion,
de-
of particu-
of MediCenter
and
Administra-
shape
a way
in the
of
Sam
Jackson
left
to say
that
of
proximal
characteristically
They
present
disease
is
an
or lesser
sever-
Demon-
equivalency
left
circumflex
effects
on
of the
two
main
and
artery
coronary
a high
Isolated
uncommon
other
in such
to patients
have
main
and
equivalent
with
coronary
left main
and
left
of the
two
the bifurca-
artery.2’
of
dysfunction.
the
a set of lesions
in the
to the same extent
as a
equivalent
left
stenosis
interact
greater
have
multiple
with
severe
angina
angina
artery
necessarily
lesions,
coronary
patients
are
anterior
descending
Patients
with
of
may
to produce
alter flow
main
is
size
from
the
of either
assumption
that
bined
vessels
factors
flow does
not establish
the
groups
of patients,
however.
disease
to a simi-
coronary
lesion
length
left
or
Is it true
coromain
equivalent
a 70 percent
branch
rheologic
artery
main
to
left
main
The
relative
of the lesions
stenoses
stration
as
is attenuated
“left
with
ity may be required
branch
vessels
that
lesion
flow
with
two
and
that
extent
a 70 percent
and
anterior
flow to the same extent
as left main
disease
if the stenoses
are sufficiently
artery.
distance
anatomic
com-
left
to be the basis
for the designation.
be possible
for combined
left anand left circumflex
coronary
artery
the
to
if the
whether
proximal
a similar
is not
of
equivalent
as
disease.
That
each
disease
indeed,
and
patients
to affect
artery
ventricular
SW
to
as in patients
unstable
3181
main
in
vessel
artery
disease
are equivalent
artery
disease.
equivalent
disease”
affect
flow
disease,
appears
Clearly,
it must
terior
descending
of
coronary
bypass
surgery.7’2#{176}
Because
it is more
precisely
correct
to designate
patients
with
“left main
equivalent
disease”
as hayDepartment
Sciences
Veterans
coronary
coronary
extent
coronary
branches,
because
of the demonstraof patients
with
left main
who have
undergone
aorto-
#{176}Fromthe Division
of Cardiology,
cine,
University
of Oregon
Health
and
circumflex
blood
narrow.
to
anterior
artery
nary
of
coroof their
be extrapolated
proximal
circumflex
descending
left main
disease
coronary
proce-
by
The
manner,
proximal
disease,”
prognostic
and therapeutic
studies
of patients
with
left
combined
left
designated
disease.”
in what
three
is also involved
or in a left
artery
system),
it is reasonable
lar
to
left anterior
descending
proximal
to the origin
equivalent
to ask
bined
(or
artery
sub-
dures
in this subgroup
of patients
has been
extensively studied.’#{176}2#{176}
When
combined
disease
of the left
circumflex
coronary
artery
and
nary
artery
is found
disease
coronary
artery
disease?
The presumption
that
artery
presentation,
vessel
dys-
similar
attracted
of revascularization
two
Does
important
survival.1’
F.R.G.P.f
ing
number
stenoses
of the
main
prin-
ventricular
a predicted
survival
vessel
disease,”9
have
interest.
angiography,
one
the
is the
significant
In addition,
of im-
but
M.B.,
right
coronary
dominant-coronary
artery
because
favorable
with
applies.
is known
factors
patients
is less
arteries
still
coronary
of
of coronary
arteries
in those
studies
may
management,5
prognosis
coronary
creases
with
number
data
in medical
that
prior
to the advent
surgery
demonstrated
of patients
disease
is related
involved.’-4
The
H. Rahimtoola,
coronary
with
com-
proximal
disease?
artery
left
disease
vessel
disease.2#{176}
pectoris
or with
incidence
left
finding.25’26
main
of
left
coronary
Therefore,
CHEST, 76: 5, NOVEMBER, 1979
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though
identifies
the
rated
left main
the patient,
from
graphic
the
main
coronary
disease
artery
lesion.
disease,
in addition
anterior
left
ease,
and
left
percent,
83
The
coronary
of co-existing
disease
not
lesions
of risk
with
factors
“left
be applied
in other
without
major
for
left
life-table
severity
may
main
was
consideration
including
and
dis-
disease
with
be quite
angina,
and
different
equivalent
disease”
verification
of their
from
and
can-
accuracy.
coronary
arteries
is difficult
to determine.
ical characteristics
of patients
with
left
nary
artery
disease
have
been extensively
The clinmain
corodescribed
but
for patients
no such
“left
characterization
main
2. Critical
coronary
artery
anterior
artery,
be
lesion
“left
combined
patients
with
able.
However,
treated
the
five-
Table
from
and
the
ten-year
1-Survival
must
also
narrowings.
The
fre-
has
not
data
been
of
established
on
survival
disease”
regarding
Cleveland
survival
Medically
(Percent)
of the
coronary
complex
equivalent
recent
patients
a lesion
disease.”
of the effects
main
effect
on flow
by a left main
with
of
is availmedically
Clinic
show
of patients
with
Treated
Patients
Survival
LAD**
(right
Two
+ circumflex
dominant
system)
vessel
LAD
*
+
disease
10 Years
Three
vessel
*Adapted
**LAD_left
59
41
62
45
40
20
47
23
circumflex
(left dominant
system)
disease
from
anterior
Proudfit
et al
descending
coronary
CHEST, 76: 5, NOVEMBER, 1979
artery
Surgical
Present
65
85
62
82
Absent
83
92
100
73
anterior
descending
left
coronary
artery
disease
vessel
disease
in a right
vessel
disease
in a left
In
this
respect,
left
many
of
were
not
the
the
do
circumflex
to
dominant
that
system
dominant
of
two
and
system9
equivalent
three
(Table
1).
disease
more
two
vessel
disease
than
disease.
Because
it is likely
in
the
to the
not
and
similar
main
lesions
proximal
data
is
Cleveland
first
Clinic
major
conclusively
left
that
series
branch
answer
vessels,
the
question,
however.
the
artery
proximal
stenoses
physiologic
disease
left
anterior
may
and
descending
in some
represent,
and left
respects,
equivalent
of left
main
may mimic
the clinical
coronary
syndrome
in some
instances,
it has not been
demonstrated
that
the combined
lesions
are the prognostic
equivalent
of left main coronary
artery
disease.
artery
group
disease
of patients
with
sufficiently
homogeneous
left
main
coronary
to
permit
meaningful
comparisons
with
cther
patient
groups?
It is now apparent
that even the label
of left main
coronary
artery
disease
is not sufficiently
specific
for
precise
prognostic
heterogeneity
tionship
extent
teries,
of
influence
“low
risk”
prognosis
of
and
identified
by
to
the
surgery
and
59 percent,
on
“high
Conley
roentgenogram
subgroups,
the
respect
al28
and
one-year
and
the
rela-
presentation,
major
coronary
and with
respect
survival.
risk”
et
to the
clinical
of other
function
a
two
Considerable
with
of involvement
and ventricular
the
chest
determination.
is apparent
A
relatively
subgroup
has
using
only
clinical
survival
history.
was
three-year
arto
been
the
ECG,
In these
97 percent
was
survival
74
percent
and 25 percent.
The presence
or absence
of
right
coronary
artery
disease
also importantly
determines
survival
(Table
2). Left
ventricular
func-
*
5 Years
et al2#{176}
Medical
Is the
in their
circumflex
vessel
in series
“left
an
equivalent”
equivalent
evidence
additive
to have
produced
or left
distal
of stenoses
are
associated
main
with
in “left main
No direct
that
In order
to that
descending
the
quency
in series
Takaro
aP
Surgical
combined
disease.”
stenoses
effects
on flow.27
that
is equivalent
left
is available
equivalent
Coronary
Medical
Though
circumflex
The
relative
importance
of the left main
coronary
artery
disease and the co-existing disease in other
with
et
Main
-.
closely
approximates
main coronary
artery
main
analysis
of
Disease
in Left
(Percent)
artery
respectively.’0
of patients
character
frequency
patients
important
Coronary
Artery
coronary
artery
artery
70 percent
artery
survival,
coronary
left
or three
coronary
and
descriptors
two
main
of right
coronary
coronary
arteries
is an
the following
reasons:
of
left
descending
62 percent,
1. Clinical
either
to the
circumflex
frequency
had
incidence
Campeau
Right
with
Survival
Disease
,-
angio-
of patients
disease
2-Three-Year
Artery
it.
83 percent
The
and
accompany
artery
Table
as a marker
which
cannot
be sepa-
hemodynamic,
which
experience,
vessel
serves
marker
clinical,
features
In our
lesion
this
tion
is also
coronary
surgery
function.
a potent
predictor
artery
disease
on survival
is
In
tute
(Table
Cooperative
the
study
3), and
Study
in the
(Table
subgroups
of survival
in left
main
patients.9”9’2#{176} The
effect
of
also
related
to ventricular
of the Montreal
Heart
Insti-
with
Veterans
Administration
4),
surgery
enhanced
survival
in
function.
onstrated
This benefit
of surgery
in the subgroups
with
function
possibly
because
abnormal
ventricular
could
normal
of small
not be demventricular
numbers
of pa-
LEFT MAIN EQUIVALENT DISEASE
Downloaded From: http://journal.publications.chestnet.org/pdfaccess.ashx?url=/data/journals/chest/21078/ on 06/16/2017
589
Table
3-Three-Year
Artery
Survival
Disease
(Percent
in
Left
Main
coronary
Coronary
in Nonrandomized
Study)
*
Fraction
Surgical
P Value
<0.45
70
65
NS
0.45-0.60
58
90
0.01
>0.60
80
92
NS
*Adapted
from
tients.
the
the
Medical
The
Campeau
extent
surgeons’
ability
extent
of distal
the suitability
influences
tients.9
coronary
The
recently
makes
disease”
interpret
vessels
but
by
also
pa-
with left
considered
designation
difficult,
currently
about
“left
if not
available
main
only
main
equivto
data.
their
CLINICAL
ease”
appears,
longer
look
More
ity
data
are
needed
of associated
ventricular
function,
tional
status,
equivalent
and
question
artery
presence
survival
disease.”
to the
on the
coronary
of the
frequency
effect
and
combination
commonly
with
“left
main
of a precise
answer
of aortocoronary
of lesions
refractory
to
produces
medical
gery can be recommended
for
or not successful
aortocoronary
longs
life.
bination
If, however,
of lesions
most
respond
apy so that symptoms
are able to lead active
bypass
angina
therapy,
that
then
patients
with
by comparing
readily
the
4-Survival
in
(Prospective,
Total
LV
Function
Abnormal
Normal
No.
from
patients
hs
.
Medical
Surgical
74
14
9
Takaro
et al.2#{176}
DE MOTS, RAHIMTOOLA
pa-
2
in
trials
With
Patients
5
it
is not
combined
and
they
from
equivalent
be
of
left
had
to
the
main
a
From
treat
pa-
proximal
circumflex
left
disbut
is made.
appropriate
main
left
small,
leap
disease
descending
leap
the
thera-
to support
main
to
the
left
coronary
coronary
arartery
of
Disease
heart
A
disease
12-year
49:489-497,
study
in
relation
of
224
to
arteriographic
patients.
Circulation
1974
of
6 Burggraf
GW,
disease:
and progbeta adrenoJ 3:735-743,
Parker
Angiographic,
JO:
Prognosis
hemodynamic,
in
coronary
and
clinical
artery
factors.
Circulation
51:146-158,
1975
7 Hultgren
HN, Takaro
T, Detre
K, et al: Veterans
administration
cooperative
study of surgical
treatment
of stable
angina:
Preliminary
results,
in,
Rahimtoola
SH (ed):
Coronary
Bypass
Surgery.
Philadelphia,
FA Davis,
1977,
pp 119-130
8 Murphy
ML, Hultgren
HN, Detre
K, et al: Treatment
of
chronic
stable angina.
N Engl J Med 297:621-627,
1977
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WL,
Bruschke
AVG,
Sones
FM
Jr: Natural
history
of obstructive
coronary
artery
disease:
Ten-year
Treatment
P Value
ischemic
findings:
1975
will be
prolong
be
an-
evaluated
randomized
of Deat
before
on
to make
5 Multicentre
International
Study:
Improvement
nosis of myocardial
infarction
by long-term
receptor
blockade
using
practolol.
Br Med
therpatients
survival
operated-on
Main
Coronary
Artery
Randomized
Study)
*
36
*Adapted
590
Left
is needed
though
of surgery
1 Bruschke
AVG,
Proudfit
WL,
Sones
FM
Jr:
Progress
study
of 590 consecutive
nonsurgical
cases of coronary
disease
followed
5 to 9 years:
I. Arteriographic
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47:1147-1153,
1973
2 Friesinger
CC, Page EE, Ross RS: Prognostic
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A, Jones
WB, Riley CP, et al: Natural history of
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Med
48:11091125, 1972
4 Humphries
JO, Kuller
L, Ross RS, et al: Natural
history
com-
to medical
and the
lives, then
currently
tients
with
medically-treated
another
era.
There
are large
cooperative
Table
is
sur-
this
data
on patients
with
and without
surgery
needed
before
recommending
surgery
to
life.
The
question,
unfortunately,
cannot
swered
on
relief of pain whether
bypass
surgery
pro-
are relieved
productive
glance,
first
disther-
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func-
surgery
on survival
in these
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population.
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medical
evidence
at
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and
other
informa-
equivalent
required
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sever-
disease,
state
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urgency
the
main
inferential
evidence,
as
another
and
current
direct
disease
with
disease.
of patients
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The
with
anterior
IMPLICATLONS
frequently
without
artery
tients
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with
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patients
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one examining
about
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of these
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tery
with
are
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two
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angina29
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optimally
decisions
current
impossible,
patients
Physicians
peutic
the
including
of
Trial.3#{176}These
studies
studies
should
contain
treated
apy and also
clinical
course
limits
the heart,
as measured
of patients
has been
the
more
with
tion
for revascularization,
nonsurgically-treated
heterogeneity
artery
disease
but
alent
in runoff
stable
angina,8
Blood
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Multicentre
unrandomized
ease”
to revascularize
vessel
disease,
of vessels
survival
in
and
pean
large
in progress
study
patients
with unstable
ing patients
with
mild
ct al.”
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surgery
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chronic
Lung
Treatment
Ejection
bypass
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study
of
53-78,
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NS
11
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of
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1975
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JH,
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