Systolic Brachial Blood Pressure Discrepancy
as a Predictor of Pan Vascular Disease and
Survival
Amjad AlMahameed, MD, MPH
Time Course of Human Atherogenesis
Cerebrovasc.
Disease
Ischemic Heart
Disease
lumen
lumen
lumen
lumen
Lesion initiation
No
symptoms
Leg PAD
+ Symptoms
Time (years)
Symptoms
What is Peripheral Arterial Occlusive Disease?
• Clinical manifestation of atherosclerosis in the peripheral arteries:
▲ Legs (Iliac, femoropopliteal, crural arteries)
▲ Cerebrovascular:
 extracranial (such as carotids and vertebral)
 intracranial
▲ Arms (subclavian arteries)
▲ Renal arteries
▲ Mesenteric arteries
• > 90% related to atherosclerotic disease
.
68 Million Americans with CVD
Stroke
4.4 million
PAD
8.4 million
HTN
50 million
And many more to come !!
Heart 16.8 million
CHF
4.6 mill
AMI
7.2 mill
Angina
6.3 mill
PAD 5-Years Mortality Rates *
80% of fatal events are cardiac or stroke
86%
100%
80%
60%
40%
20%
0%
15%
Breast CA
18%
Hodgkin's
28%
PAD
American Cancer Society. Cancer Facts and Figures. 1997
38%
Colon CA
Lung CA
PAD and Relative Risk of Death
Relative Risk (95% CI)
10.0
8.0
5.9
(3.0–11.4)
6.6
(2.9–14.9)
6.0
4.0
3.1
(1.9–4.9)
2.0
0.0
All Causes
Cardiovascular
Disease
Cause of Death
Adapted from Criqui MH et al. N Engl J Med. 1992;326:381.
Coronary Heart
Disease
PAD Survival as a Factor of the ABI
Patients Survival (%)
100
80
ABI >0.85
60
ABI 0.40–0.85
40
ABI <0.40
20
0
2
6
4
Year
McKenna M, et al. Atherosclerosis. 1991;87:119-128.
8
10
JNC 7: Treatment Algorithm for Hypertension
Lifestyle modifications
Not at goal blood pressure (<140/90 mm Hg)
(<130/80 mm Hg for those with diabetes or chronic kidney disease)
Initial drug choices
Without compelling indications
Stage 1 hypertension
(SBP 140–159 or DBP 90–99 mm Hg)
Thiazide-type diuretic for most.
May consider ACEI, ARB, BB, CCB,
or combination.
Stage 2 hypertension
(SBP 160 or DBP 100 mm Hg)
Two-drug combination for most
(usually thiazide-type diuretic and
ACEI or ARB or BB or CCB).
With compelling indications
Drugs for compelling indications
Other antihypertensive drugs
(diuretic, ACEI, ARB, BB, CCB) as
needed.
Not at goal blood pressure
Optimize dosages or add additional drugs until goal blood pressure is achieved.
Consider consultation with hypertension specialist.
SBP=systolic blood pressure; DBP=diastolic blood pressure; ACEI=angiotensinconverting enzyme inhibitor; ARB=angiotensin receptor blocker; BB=b-blocker;
CCB=calcium channel blocker
JNC 7. May 2003. NIH publication 03-5233.
Atherosclerotic Plaque: Effect on Hemodynamics
Intima
Plaque
Vessel Lumen
Encroachment on the lumen by a
plaque has to be relatively extensive
before changes in hemodynamics
become manifest:
- Aorta: 90%
- Iliac, femoral, carotid, renal: 70-90%
Media
Measurement of systolic pressure
provides a quantitative, objective, and
sensitive index on the occlusive process
Systolic pressure is sensitive index
of the fall in mean pressure while
diastolic pressure does not fall until
the stenosis is severe
Libby P. Lancet. 1996;348:S4-S7. Carter S, Role of pressure measurement in vascular disease in Bernstein EF,
editor, Noninvasive Diagnostic Techniques in Vascular Disease, Mosby, 1985:513-544
Hypertension and BBPD: Why Are we Talking
About This?
• HTN is a public health problem (50 Million Americans)
• HTN is associated with increased mortality and morbidity1
• HTN is a modifiable risk factor: accurate early diagnosis is vital2
• Joint National Committee (JNC-VII)3
• British Hypertension Society (BHS-IV)4
• World Health Organization (WHO)5
Make no mention of which arm to
measure BP in or of BBPD and its
significance.
• Earlier guidelines recommended measuring BP in both arms during the
initial visit and using the higher pressure for all future measurements6-10
• Very few practitioners follow even the most critical aspects of BP
measurements guidelines leading to under and over dx of HTN10
(1)
(2)
(3)
(4)
Stamler J et al. Arch Intern Med 1993;153:598
Perloff D et al. Circulation 1993;88:2460
JNC VII JAMA 2003
Williams B et al. BMJ 2004;328:634
(5) WHO, J Hypertension 1999;17:151-183
(6-10) JNC-V 1993, AHA: Circulation 1967; 36:980
HTN Reviews BMJ 1979 and 1986, JAMA 1995
(11) Cushman Arch Intern Med 1996;156:1922
Occlusive Upper Extremity Arterial Disease
•
Atheroclerosis
•
Takayasu’s disease
•
Embolism/thrombus
•
Thoracic outlet syndrome
•
Complication of angiography
•
Buerger’s disease
•
Trauma
•
Aortic disease (dissection,
coarctation, syphilitic aortitis,
supravalvular aortic stenosis)
•
No specific number for BBPD has
been spelled out as clinically
significant in textbooks
•
BBPD of 10-15 mm Hg should
raise suspicion of
scubclavian/axilary disease
•
Differences of 20-30 mm Hg is
indicative of disease
•
BBPD may be seen in patients
with no known disease
•
BBPD may underestimate severity
of disease in case of bilateral
stenosis
Limitation of BP measurement
Vessel Wall Rigidity:
Limb /Cuff compatibility
(pseudo-elevation or -reduction)
- More common in L ext. (>10%)
- Related to Monckeberg’s
sclerosis
- Seen in DM, chronic corticosteroid therapy, HD patients,
after renal transplantation,
neuropathy an surgical
sympathectomy
- Manifests as incompressibility
of the vessel
Obstruction in parallel vessels
(only higher pressure recorded)
Vasomotor tone changes
(exercise and heat effect)
Time, effort, nonreimbursement issues
Effects of Routine Activities on Blood Pressure
(adapted from Campbell et al2)
Systolic blood pressure
Diastolic blood pressure
Attending a meeting
 20
 15
Commuting to work
 16
 13
Dressing
 12
 10
Walking
 12
6
Talking on telephone
 10
7
Eating
9
 10
Doing desk work
6
5
Reading
2
2
 0.3
1
Watching television
24-Hour Ambulatory BP Measurement
Interpreting BP Readings
• The following can cause falsely low pressure reading:
- An arm cuff that is too wide.
- Recent exercise.
- Not smoking for a while after heavy, long-term smoking.
- BP taken in the flaccid paretic arm
• Falsely high pressure can result from the following:
- An arm cuff that is too small.
- Talking during the test.
- Having recently consumed foods or beverages
(such as coffee) that raise blood pressure.
Historical Perspective: What We Knew
•
Several studies in the first half of the 20th century found a difference of >
10 mm Hg between arms in 20-45% of patients studied(1-5)
Osler 1915: “While the arterial blood pressure in aneurysm is
• Most
of these
studies
were small,
not standardized,
limited
to
either
normal
or slightly
above,
in a majority
of cases
of
hypertensive
patients there is a marked difference in the blood
thoracic
aneurysm
pressure in the two arms and when this is greater than 20
• BBPD wasmmHg
much less encountered when measurements were obtained
it is a point in favor of aneurysm”
simultaneously after hypertensive patients rested in supine position for
30 minutes (5% of patients had BBPD > 10 mmHg)(6)
•
(Osler W. Modern Medicine. Vol 4. Philadelphia, Lea & Fibiger, 1915, P 498)
Significant BBPD is present in ambulatory patients presenting to ER
without known vascular pathological lesion(7)
(1) Cyriax EF, Q J Med 1921;14:309-313.
(2) Kay WE and Gardner KD, West J Med 1930;33:578
(3) JAMA 1939;112:2458.
(4) Rueger MJ, Ann Intern Med 1951;35:1023-1027.
(5) Amsterdam B and Amsterdam AL, N Y J Med 1943,43:2294
(6) Harrison EG, Roth GM, Hines EAZ, Circulation 1960;22:419
(7) Singer AJ and Hollander JE. Arch Intern med 1996;156:2005
2008
Meticulous attention to
details is mandatory and the
Korotkoff method
instruments should be
calibrated.
Patient should be in supine
position.
Beware of ABI limitations
ABI =
ABI is 95% sensitive and
99% specific for PAD
BBI =
Lower extremity systolic pressure
Brachial artery systolic pressure
Lower
systolic brachial pressure in one arm
_____________________________________________________________
Higher systolic brachial pressure in other arm
The “Normal” Difference in Bilateral BP Recordings
accidental participants (by convenience) included hospital workers (physicians, nurses, janitors, etc)
Random BP by 2 observers using standard mercury cuff while seated
BP Status
Number of
participants
Average BBPD > 10 Related to sex/
Coefficient
age (yrs)
(mmHg)
hand dominance of variation
Normotensiv1
100
38
15%
No
5%
Hypertensiv2
100
55
18%
No
2%
Although no objective evaluation of the aortic arch, subclavian or axillary
arteries was undertaken, the authors concluded that the 15% and 18% BBPD
rate represent “false-positive” results and are related to “normal variability”
(1) Pesola G et al, Am J Emerg Med 2001;19:43-45)
(2) Pesola G et al, Academic Emergency Med 2002;9:342-345)
Assessment of Interarm BP Differences in the ER
Prospective observational study on a convenience sample of 610
ambulatory patients seen at a university hospital ER (9/5-23 , 1996)

324 (53%) had a BBPD > 10 mmHg
- Patients were seated

113 (19%) had a BBPD > 20 mmHg
- Automated BP monitor
Mean BBPD was significantly higher
in pts w known CAD (14.5 vs. 10.4 mm
Hg, P = 0.05)
- “Sequential” BP (R
arm then L), 300 pts
- “Almost simultaneous”
BP measurement,
next 310 pts
BBPD unrelated to age, sex, race, BP ,
cardiovascular risk factors, pulse,
underlying diagnosis
Singer AJ and Hollander JE. Arch Intern med 1996;156:2005-2008
The normal Range of Interarm Differences in BP (Orme S et al. Age and Ageing 1999;28:537-542)
462 subjects: 98 with HTN, CAD, PAD (age 68 yrs) and 364 w/o hx of CVD (49 yrs). Supine
position for 10 minutes. Mean of 4 simultaneous BP readings (each arm) used for BBPD.
Normal Range of BBPD
Experimental
Some subjects have clinically
Important BBPD
In Clinical
Practice
Systolic
W/O CVD
- 8 to 10.3 (-8.6 to 10.8)
- 8 to 11
All Group
- 8.7 to 10.9 (-9.2 to 11.4)
- 9 to 11
BBPD is not related to age, gender,
mean BP, and history of CVD
“Normal” range for BBPD (systolic)
Is -9 to 11 mmHg
Diastolic
W/O CVD
- 10 to 10 (-10.5 to 10.5)
- 10 to 10
All Group
- 10.2 to 10.2 (-10.7 to 10.7)
- 10 to 10
“Normal” range for BBPD (diastolic)
Is -10 to 10 mmHg
400 participants (mean age 56), 86 (21%) with history of HTN. Sit quietly for 5
minutes. BP measured simultaneously using 2 automated monitors.
Systolic BBPD:
 > 10 mmHg: 80 participants (20%)
 > 20 mmHg: 14 participants (3.5%)
Diastolic BBPD:
 > 10 mmHg: 45 participants (11%)
 > 20 mmHg: 15 participants (~4%)
BBPD was not associated with:
 Age
 Sex
 Ethnicity
 R or L arm circumference
 Handedness
 Being hypertensive
 Previous history of CVD
Participants with Clinically Significant Difference in BP (BBPD)
BBPD Quintiles (mmHg), n (%)
0-5
6-10
11-15
16-20
>20
Systolic
231 (57.8)
89 (22.3)
50 (12.5)
16 (4.0)
14 (3.5)
Diastolic
284 (71.0)
71 (17.8)
16 (4.0)
14 (3.5)
15 (3.8)
Lane D et al. J of Hypertension 2002;20:1089-95
BBPD in Primary Care Patients1
• 237 primary care patients
• Systolic BBPD > 20 mmHg: 23%
•
> 10 mmHg: 40%
BBPD in Nursing Home Residents2
• 528 NH residents (able to give IC)
• Systolic BBPD > 10 mmHg: 14%
• Diastolic BBPD > 10 mmHg: 4%
(1)
(2)
Cassidy P. J Hum Hypertension, 2001;15:519-522.
Mendelson G. Cardiology in Review 2004;12:276-278
No association
between BBPD
(S & D) and:
- HTN
- Vascular Dz
- DM
- Dyslipidemia
52 patients (66 yrs) with occlusive or aneurysmal disease documented or suspected
PAD (prior surgery, symptoms of claudication, auscultation of a bruit, absent pulses)
Cardiac Catheterization
With nonselective aortic
Arch angiography
35.4% had
> 30% stenosis
48 technically
acceptable
studies
18.7% had
> 50% stenosis
Gutierrez GR et al. Angiology 2001;52:189-194
1 patient ,total
LSC A occlusion
515 patients referred for
Cardiac Catheterization
17 (3.5%) subjects
had L SCA stenosis
(> 60%)
492 had complete
Data (age 62)
Incidence (%)
Overall Population
Potential CABG Patients
No significant angiographic CAD
1.4
-
1- or 2-vessel CAD
3.3
-
-
5.3
1.5
2.4
4.3
6.2
3-Vessel or left main CAD
No PAD
HTN
Smoking history
The only independent predictor of L SCA
4.3 or documented)
Stenosis: PAD (clinical
6.5
Diabetes Mellitus
6.8
8.3
Cerebrovascular disease
7.6
9.1
11.5 9errorrrrrrrrrrrr
11.8
PAD (30% of participants had PAD)
English J et al. Cathet Cardiovasc Intervent 2001;54:8-11
Characteristics of BBPD of > 10 mmHg and > 20 mmHg in predicting L SCA stenosis
BBPD
> 10 mmHg
> 20 mmHg
Sensitivity
65%
35%
Specificity
85%
94%
Positive Predictive Value
13%
19%
Negative Predictive Value
99%
98%
•
BBPD should not be used as screening method for L SCA stenosis pre
CABG
•
Proximal L SCA angiography is recommended for patients with > 10 mmHg
BBPD or those with clinical evidence of PAD regardless of the BBPD
•
If moderate proximal SCA stenosis is present, translesional measurement
of the gradient is recommended.
English J et al. Cathet Cardiovasc Intervent 2001;54:8-11
134 hospitalized patients: 58 with PAD, 38 with CAD, and 38 controls (no CAD/PAD). The
mean of 3 BP measurements (Dinamap) for each arm used for BBPD calculation (sequentially).
BBPD (absolute systolic BP ∆ mmHg)
> 10 mmHg
> 15 mmHg
> 20 mmHg
> 45 mmHg
Control (n = 38)
5 (13%)
0 (0%)
0 (0%)
0 (0%)
CAD (n = 38)
6 (16%)
3 (8%)
1 (3%)
0 (0%)
PAD (n = 58)
24 (41%)*§
16 (28%)‡§
12 (21%)†§
6 (10%)*§
* P < 0.05 vs. control, † P < 0.01 vs. control, ‡ P < 0.001 vs. control, § P < 0.05 vs. CAD
- No relationship between BBPD and sex, age, smoking, HTN, or diabetes.
- Relatively high incidence and magnitude of BBPD in the PAD group
compared to both CAD and control groups
- Does BBPD reflect the atherosclerotic “burden” of a particular patient?
Frank SM et al. Anesthesiology 1991;75:457-463.
P < 0.0001
•
Pairs of BP measurements were
taken from 83 of 280 patients (age
69 years) attending general practice
(5/94-10/95)
•
64% had HTN, 16% smokers, 11%
hx CAD, 5% hx of CVA
•
11 pta (13%) had S BBPD > 20
mmHg
•
14 pts (17%) had D BBPD > 10
mmHg
•
5.6 years F/U
•
17 pts (20%) had CAD events, 2 had
CVA, 6 died (1 from cancer and 5
from CVD)
Mean Event-Free Survival (years)
Time-to-event survival function plot for
clinically important diastolic differences
Clark CE and Powell RJ. Family Practice 2002; 19: 439–441.
S BBPD > 20
mmHg
D BBPD > 10
mmHg
3.5 (vs. 4.9 years
for S BBPD < 20)
3.3 (vs. 5.0 years
for DBBPD < 10)