From the Departments of Medicine (W.H.C., D.S.W.H., S.L.H., R.T.F.C.) and
Surgery (S.W.K.C.), The University of Hong Kong, Queen Mary Hospital, Hong
Kong.
Correspondence to David Sai Wah Ho, MD, Associate Professor of Medicine, Department of Medicine, The University of Hong Kong, Queen Mary Hospital, Pokfulam, Hong Kong. E-mail dswho{at}hkucc.hku.hk
Methods—We studied 153 consecutive Chinese patients with
angiographically documented CAD. Duplex ultrasonography was performed
to identify any underlying extracranial carotid and vertebral artery
disease. Patient demographics; vascular risk factors; history of
myocardial infarction, transient ischemic attack (TIA) or
stroke; concomitant peripheral vascular disease (PVD);
degree of left ventricular dysfunction; and extent and
severity of CAD were also noted and analyzed.
Results—Significant (
Conclusions—Significant ECCVD is not uncommon in Chinese patients
with CAD, and the prevalence is comparable with that reported in white
populations. Patients with a history of diabetes, hypertension, TIA,
stroke, and PVD are more likely to have concomitant ECCVD.
CAD has been associated with ECCVD in white population series. In
patients with CAD, significant ECCVD has been reported to be
present in 12% to 28%.13 14 15 16 17 18 There have
been no similar studies in Chinese patients with CAD. The objectives of
this study are therefore to (1) determine the prevalence, distribution,
and severity of ECCVD in Chinese patients with CAD and (2) identify the
clinical variables associated with ECCVD.
All patients underwent coronary angiography and left
ventriculography by the transfemoral route. A biplane technique was
used, and each coronary artery was studied by at least two
different projections. CAD was defined as
Statistical analysis was performed using the
In our study, instead of performing another stroke or autopsy series we
took a different approach to address the impression that ECCVD is rare
among Chinese. It has been well reported that ECCVD is associated with
CAD. In four studies in white patients13 14 15 16 on
the prevalence of carotid artery disease among patients with CAD,
significant (defined as
Limitations
Although the role of ultrasound in the assessment of vertebral artery
disease is less well defined and the accuracy of duplex scanning in
identifying vertebral artery disease is lower than that of carotid
artery disease, sensitivities of 73% to 76% and specificities of 94%
to 97% have been reported in two large
series.21 34 In any case, the relatively poor
sensitivity of duplex scanning in identifying significant vertebral
artery disease could only have underestimated the true prevalence of
ECCVD, further emphasizing that ECCVD in Chinese is not as rare as
previously thought.
This study addressed only the prevalence of ECCVD among Chinese
patients with CAD, not the prevalence in the general population or
stroke population. Relatively few statistics are available on the
prevalence of CAD in Chinese. Although the prevalence of CAD among Hong
Kong Chinese has been reported to be lower than that in white
populations,35 one autopsy
series36 found the incidence of
atherosclerosis among Hong Kong Chinese to be
comparable with that in Western populations. Local cardiologists have
also noted an increasing demand for coronary care units,
coronary angiography, angioplasty, and surgery. For example,
the demand for coronary angioplasty in Hong Kong (500
procedures per million population per year) is comparable with that in
many European countries.37 Nevertheless, many
patients who suffer stroke or TIA do not have concomitant CAD.
Significant racial difference in the prevalence of ECCVD among stroke
patients may still exist. Thus, caution should be exercised in
generalizing these results to the general population.
In conclusion, in contrast to previous reports, we find that
significant extracranial atherosclerotic cerebral arterial
disease is not uncommon in Chinese patients with CAD. The prevalence of
21% is comparable with those reported for white populations. This is
in accordance with two recent studies26 27 in
patients of Asian origin that suggest a rising prevalence of ECCVD in
Japanese and Taiwan Chinese stroke victims. Among patients with CAD,
clinical variables such as diabetes, hypertension, TIA, stroke, and
PVD were predictive of concomitant extracranial cerebrovascular
disease. These findings are also in accord with those reported in
studies in white patients.
Received August 13, 1997;
revision received December 3, 1997;
accepted December 18, 1997.
2.
Sacco RL, Ellenberg JH, Mohr JP, Tatemichi TK, Hier
DB, Price TR, Wolf PA. Infarcts of undetermined cause: the NINCDS
Stroke Data Bank. Ann Neurol. 1989;25:382–390.[Medline]
[Order article via Infotrieve]
3.
Brust RW. Patterns of cerebrovascular disease in
Japanese and other population groups in Hawaii: an angiographic study.
Stroke. 1975;6:539–542.
4.
Nishimaru K, McHenry LC Jr, Toole JF. Cerebral
angiographic and clinical differences in carotid system transient
ischemic attacks between American Caucasian and Japanese
patients. Stroke. 1984;15:56–59.
5.
Caplan LR, Gorelick PB, Hier DB. Race, sex, and
occlusive cerebrovascular disease: a review. Stroke. 1986;17:648–655.
6.
Inzitari D, Hachinski VC, Taylor DW, Barnett HLM.
Racial differences in the anterior circulation in cerebrovascular
disease: how much can be explained by risk factors? Arch
Neurol. 1990;47:1080–1084.
7.
Feldmann E, Daneault N, Kwan E, Ho KJ, Pessin MS,
Langenberg P, Caplan LR. Chinese-white differences in the distribution
of occlusive cerebrovascular disease. Neurology. 1990;40:1541–1545.[Medline]
[Order article via Infotrieve]
8.
Leung SY, Ng THK, Yuen ST, Lauder IJ, Ho FCS. Pattern
of cerebral atherosclerosis in Hong Kong Chinese:
severity in intracranial and extracranial vessels. Stroke. 1993;24:779–786.
9.
Huang CY, Chan FL, Yu YL, Woo E, Chin D.
Cerebrovascular disease in Hong Kong Chinese. Stroke. 1990;21:230–235.
10.
Liu HM, Tu YK, Yip PK, Su CT. Evaluation of
intracranial and extracranial carotid steno-occlusive diseases in
Taiwan Chinese patients with MR angiography: preliminary experience.
Stroke. 1996;27:650–653.
11.
Chen D, Roman GC, Wu GX, WU ZS, Yao CH, Zhang M, Hirsch
RP. Stroke in China (Sino-MONICA-Beijing study): 1984–1986.
Neuroepidemiology. 1992;11:15–23.[Medline]
[Order article via Infotrieve]
12.
Cheng XM, Ziegler DK, Lai YHC, Li SC, Jiang GX, Du XL,
Wang WZ, Wu SP, Bao SG, Bao QJ. Stroke in China, 1986 through 1990.
Stroke. 1995;26:1990–1994.
13.
Breslau PJ, Fell G, Ivey TD, Bailey WW, Miller DW,
Strandness DE Jr. Carotid arterial disease in patients
undergoing coronary bypass operations. J Thorac
Cardiovasc Surg. 1981;5:765–767.
14.
Barnes RW, Liebman PR, Marszalek PB, Kirk CL, Goldman
MH. The natural history of asymptomatic carotid disease in
patients undergoing cardiovascular surgery.
Surgery. 1981;90:1075–1083.[Medline]
[Order article via Infotrieve]
15.
Faggioli GL, Curl GR, Ricotta JJ. The role of carotid
screening before coronary artery bypass. J Vasc
Surg. 1990;12:724–731.[Medline]
[Order article via Infotrieve]
16.
Sanguigni V, Gallu M, Strano A. Incidence of carotid
artery atherosclerosis in patients with
coronary artery disease. Angiology. 1993;44:34–38.
17.
Salasidis GC, Latter DA, Steinmetz OK, Blair J, Graham
AM. Carotid artery duplex scanning in preoperative assessment for
coronary artery revascularization: the
association between peripheral vascular disease, carotid
artery stenosis, and stroke. J Vasc Surg. 1995;21:154–162.[Medline]
[Order article via Infotrieve]
18.
Berens ES, Kouchoukos NT, Murphy SF, Wareing TH.
Preoperative carotid artery screening in elderly patients undergoing
cardiac surgery. J Vasc Surg. 1992;15:313–323.[Medline]
[Order article via Infotrieve]
19.
Zierler RE. Basic and practical aspects of
cerebrovascular testing. In: Bernstein EF, ed. Vascular
Diagnosis. 4th ed. St Louis, Mo: Mosby Yearbook; 1993.
20.
Bendick PJ, Jackson VP. Evaluation of the vertebral
arteries with duplex sonography. J Vasc Surg. 1986;3:523–530.[Medline]
[Order article via Infotrieve]
21.
Ackerstaff RGA, Grosveld WJHM, Eikelboom BC, Ludwig JW.
Ultrasonic duplex scanning of the pre-vertebral segment of the
vertebral artery in patients with cerebral
atherosclerosis. Eur J Vasc Surg. 1988;2:387–393.[Medline]
[Order article via Infotrieve]
22.
Huang YN, Gao S, Li SW, Huang Y, Li JF, Wong KS, Kay R.
Vascular lesions in Chinese patients with transient ischemic
attacks. Neurology. 1997;48:524–525.
23.
Martin MJ, Whisnant JP, Sayre GP. Occlusive vascular
disease in the extracranial cerebral circulation. Arch
Neurol. 1960;5:530–538.
24.
Fisher CM, Gore I, Okabe N, White PD.
Atherosclerosis of the carotid and vertebral arteries:
extracranial and intracranial. J Neuropathol Exp
Neurol. 1965;24:455–476.
25.
Giroud M, Lemesle M, Quantin C, Vourch M, Becker F,
Milan C, Brunet-Lecomte P, Dumas R. A hospital-based and a
population-based stroke registry yield different results: the
experience in Dijon, France.
Neuroepidemiology. 1997;16:15–21.[Medline]
[Order article via Infotrieve]
26.
Nagao T, Sadoshima S, Ibayashi S, Takeya Y, Fujishima
M. Increase in extracranial atherosclerotic carotid lesions in patients
with brain ischemia in Japan. Stroke. 1994;25:766–770.[Abstract]
27.
Jeng JS, Chung MY, Yip PK, Hwang BS, Chang YC.
Extracranial carotid atherosclerosis and vascular risk
factors in different types of ischemic stroke in Taiwan.
Stroke. 1994;25:1989–1993.[Abstract]
28.
Boiten J, Lodder J. Lacunar infarcts: pathogenesis and
validity of the clinical syndromes. Stroke. 1991;22:1374–1378.
29.
Tegeler CH, Shi F, Morgan T. Carotid stenosis
in lacunar stroke. Stroke. 1991;22:1124–1128.
30.
Hennerici M, Freund HJ. Efficacy of CW-Doppler and
duplex system examinations for the evaluation of extracranial carotid
disease. J Clin Ultrasound. 1984;12:155–161.[Medline]
[Order article via Infotrieve]
31.
Fischer GG, Anderson DC, Farber R, Lebow S. Prediction
of carotid disease by ultrasound and digital subtraction angiography.
Arch Neurol. 1985;42:224–227.
32.
Chambers BR, Norris JW. Outcome in patients with
asypmtomatic neck bruits. N Engl J Med. 1986;315:860–865.[Abstract]
33.
Taylor LM Jr, Lobba L, Porter JM. The clinical
course of carotid bifurcation stenosis as determined by duplex
scanning. J Vasc Surg. 1988;8:255–261.[Medline]
[Order article via Infotrieve]
34.
Jak JG, Hoeneveld H, van der Windt JM. A six-year
evaluation of duplex scanning of the vertebral artery: a non-invasive
technique compared with contrast angiography. J Vasc
Technol. 1989;13:26–30.
35.
Coronary heart disease in Hong Kong.
Public Health Report, Department of Health, Hong Kong. 1994;1:14–32.
36.
Cheung FM, Pang SW, Loke SL, Lau SH. Coronary
atherosclerosis among Hong Kong Chinese: a
histological and morphometric study using electronic
digitizer. Pathology. 1984;16:381–386.[Medline]
[Order article via Infotrieve]
37.
Unger F. Interventions on the coronaries: PTCA versus
CABG. J Intervent Cardiol. 1996;9:3–7.
© 1998 American Heart Association, Inc.
Original Contributions
Prevalence of Extracranial Carotid and Vertebral Artery Disease in Chinese Patients With Coronary Artery Disease
Abstract
Top
Abstract
Introduction
Subjects and Methods
Results
Discussion
References
Background and Purpose—Chinese have
been reported to have an extremely low prevalence rate of carotid and
vertebral artery disease in comparison with whites. Previous studies,
however, have been limited to general hospital stroke admission or
postmortem series and were prone to selection bias. Extracranial
cerebrovascular disease (ECCVD) is associated with coronary
artery disease (CAD) in whites. Data associating ECCVD with CAD in
Chinese patients are not available. 
50%) stenosis of one or more of
the extracranial cerebral arteries was found in 32 patients (21%). The
internal and external carotid arteries were involved in 17 of 153
patients (11%) and 19 of 153 patients (12%), respectively. The
vertebral artery was involved in 9 of 153 patients (6%) and the common
carotid artery in 3 of 153 (2%). Diabetes mellitus, hypertension, a
history of TIA or stroke, and PVD were significantly associated with
the presence of ECCVD.
Key Words: carotid artery diseases • cerebral arteries • Chinese • coronary artery disease • vertebral artery
Introduction
Top
Abstract
Introduction
Subjects and Methods
Results
Discussion
References
Atherothrombosis of
the large cerebral arteries is an important cause of cerebrovascular
disease and accounts for 30% to 60% of all ischemic
strokes.1 2 The distribution and severity of
atherosclerotic cerebrovascular disease has been reported to vary among
patients of different ethnic origins.3 4 5 6 7 8 9
Previous studies reported that Chinese stroke patients had more
intracranial small-vessel disease than did white stroke patients,
whereas extracranial disease was extremely rare. However, these reports
were limited by relatively small study sample
size8 10 or lack of detailed clinical and
laboratory (eg, duplex ultrasonography or cerebral arteriography)
evaluation for extracranial disease.9 Another
major limitation of any general hospital stroke
presentation or autopsy series in developing countries is
selection bias. This includes factors relating to the popularity of
alternative therapy, difference in economic power and threshold of
hospital presentation between males and
females,11 12 and difference in rates of
presentation to and admission by a private versus public
hospital. Thus, in Hong Kong, patients with hemorrhagic strokes are
more likely to present to and be admitted by a hospital, whereas
those with minor strokes or TIAs are more likely to seek treatment from
Chinese herbalists or acupuncturists or are refused admission by an
overcrowded public hospital. In fact, patients with TIAs have often
been excluded from previous series.8 9 11 12
These patients may have significant extracranial cerebrovascular
disease with large artery to small artery embolization as a cause of
the TIA or minor stroke.
Subjects and Methods
Top
Abstract
Introduction
Subjects and Methods
Results
Discussion
References
We included in this study 153 consecutive patients
presenting to our center for diagnostic cardiac
catheterization who had angiographically proved CAD. A
detailed history was taken and physical examination performed by one of
two physicians (W.H.C. and D.S.W.H.). Data collected included age, sex,
history of cigarette smoking, and presence of diabetes mellitus,
hypertension, hypercholesterolemia (defined as
pretreatment fasting total cholesterol level 5.4
mmol/L), TIA, stroke, and PVD. The overall patient characteristics are
summarized in Table 1
.
View this table:
[in a new window]
Table 1. Patient Characteristics 50% luminal diameter
stenosis of one or more of the major epicardial
coronary arteries. The extent and severity of CAD as well as
the left ventricular systolic function were noted.
Ultrasonographic assessment of the extracranial carotid and vertebral
arteries was performed in every patient. An Accuson duplex ultrasound
system (128XP/10) with a 5-MHz scanning probe was used. The duplex
examination was carried out by a single ultrasonographer, and the
results were interpreted independently by two different readers. Peak
systolic velocities of 1.25 m/s and 1.4 m/s were used to
define the presence of a lesion in the carotid arteries of 50%
stenosis and 80% stenosis,
respectively.19 A focal velocity increase of
>0.4 m/s in peak systole accompanied by disturbed flow in the adjacent
(downstream) portion of the vessel was used to define the presence of a
vertebral artery lesion of 50%
stenosis.20 21 
2 test. A value of P<.05 was
considered statistically significant.
Results
Top
Abstract
Introduction
Subjects and Methods
Results
Discussion
References
Significant (50%) stenosis of 1 extracranial cerebral
arteries was found in 32 patients (21%; Table 2). The lesions were located in the
common carotid artery in 3 of 153 patients (2%), the ICA in 17 of 153
patients (11%), the external carotid artery in 19 of 153 patients
(12%), and the vertebral artery in 9 of 153 patients (6%). Bilateral
ICA stenosis was found in 3 patients (2%). Nine (6%) patients
had 80% stenosis in one or both of the ICAs. The
characteristics of patients with and without ECCVD are shown in Table 1
. Diabetes mellitus, hypertension, and a history of TIA, stroke, and
PVD were significantly associated with the presence of ECCVD.
View this table:
[in a new window]
Table 2. Distribution of Extracranial Cerebrovascular
Disease
Discussion
Top
Abstract
Introduction
Subjects and Methods
Results
Discussion
References
Many published series have reported on the differences in ECCVD
between whites and Orientals.3 4 5 6 7 8 9 An angiographic
study4 in Japanese stroke patients showed that
extracranial ICA lesions were less frequent and milder in Japanese than
in Americans, whereas intracranial disease was more common in Japanese.
Studies in Chinese patients with TIA or ischemic
stroke3 7 10 22 have reported a 9% to 30%
prevalence of extracranial carotid disease, as opposed to 30% to 60%
in white patients. An autopsy series in Hong Kong
Chinese8 revealed extracranial carotid artery
stenosis of 50% in 18% and total occlusion in 2% of the
cases. This is much lower than the corresponding figures of 40% and
8% to 11% reported in two white population
series.23 24 Small sample size and selection bias
are major limitations of these studies. In addition, hemorrhagic
strokes are often overrepresented in hospital-based series,
because patients often present with more severe symptoms, such as
headache, vomiting, and loss of consciousness.25
This is all the more important in developing countries, because
patients with milder or transient symptoms tend to be turned away by
overcrowded public hospitals or seek alternative treatment from
herbalists and acupuncturists. 50%) ICA stenosis was found in 12%
to 28% of the patients. When a definition of 80% was used, the
prevalence of ICA stenosis was reported to range from 6% to
9%.17 18 In our study, we found a prevalence of
11% and 6% when 50% and 80%, respectively, were used to define
significant ICA stenosis. Thus, the prevalence of significant
ICA stenosis in our cohort is comparable with those reported in
series examining white patients, and significant ECCVD is definitely
not rare among Chinese. This is in accord with two recent
studies26 27 on patients of Asian origin that
suggest a rising prevalence of ECCVD in Japanese and Taiwan Chinese
stroke victims. Thus, severe extracranial ICA stenosis was
found to be five times more prevalent in a recent cohort (1989 to 1993)
compared with an earlier cohort (1963 to 1965) of Japanese
ischemic stroke patients.26 In a recent
study on Taiwan patients with cortical
infarcts,27 ipsilateral ICA stenosis of
50% was present in 32% of the cases. This compares with the
findings of two studies in white patients that 37% of the patients
with cortical infarcts28 and 41% of those with
nonlacunar infarctions29 had ipsilateral ICA
stenosis of 50%. Increased affluence and westernization of
lifestyles in our region could partly explain the rising prevalence of
ECCVD in Chinese and Japanese.26 Another
explanation is increased diagnosis and detection as a result of a lower
threshold of presentation to and admission by hospitals in
these countries, in turn resulting from improved public education and
increased health spending. Availability and improved treatment for
ECCVD in these countries over the last two decades may have also played
a part. All these factors could explain the rising prevalence of
atherosclerotic disease in the extracranial cerebral arteries in
Chinese. Among patients with CAD in our series, diabetes, hypertension,
TIA/stroke, and PVD were identified as predictors of concomitant ECCVD.
This is also in accord with two other studies that found TIA/stroke and
PVD to be significantly associated with severe carotid
stenosis.17 18
Duplex scanning is an accurate, noninvasive method for identifying
significant carotid artery disease. A sensitivity of up to 95% and
specificity of up to 90% have been
reported.30 31 32 33 In our vascular laboratory, a
peak systolic velocity of 1.25 m/s as a cut point in
identifying carotid artery stenosis of 50% is associated
with a sensitivity of 90% and specificity of 95%. A peak
systolic velocity of 1.4 m/s as a cut point in identifying
carotid artery stenosis of 80% is associated with a
sensitivity of 95% and specificity of 95%. These figures were based
on an analysis of 80 consecutive cases in which each patient
had undergone both angiography and duplex scanning in our center.
Selected Abbreviations and Acronyms
CAD
=
coronary artery disease
ECCVD
=
extracranial cerebrovascular disease
ICA
=
internal carotid artery
PVD
=
peripheral vascular disease
TIA
=
transient ischemic attack
References
Top
Abstract
Introduction
Subjects and Methods
Results
Discussion
References
1.
Mohr JP, Caplan LR, Melski JW, Goldstein RJ,
Duncan GW, Kistler JP, Pessin MS, Bleich HL. The Harvard Cooperative
Stroke Registry: a prospective registry. Neurology. 1978;28:754–762.
This article has been cited by other articles:
 |
|
 |
|
  M. A. Elsharawy Carotid endarterectomy in high-risk Arab patients Interactive CardioVascular and Thoracic Surgery, January 1, 2009; 8(1): 100 - 103. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. S. Thomas, F. Habib, K. Varghese, M. T. Abraham, N. J. Hayat, and G. Cherian Disease of Proximal Part of Vertebral Artery in Patients with Coronary Artery Disease Angiology, March 1, 2003; 54(2): 205 - 209. [Abstract] [PDF]
|
|
|
|
 |
|
 G.C. Cloud and H.S. Markus Diagnosis and management of vertebral artery stenosis QJM, January 1, 2003; 96(1): 27 - 54. [Full Text] [PDF]
|
|
|
|
|
|
C. S. Thomas, K. Varghese, F. Habib, M. T. Abraham, N. J. Hayat, and G. Cherian Extent and Severity of Atherosclerotic Vascular Disease in Patients Undergoing Coronary Angiography The Kuwait Vascular Study Angiology, January 1, 2003; 54(1): 85 - 92. [Abstract] [PDF]
|
|
|
|
 |
|
 Y. Arad, D. Newstein, F. Cadet, M. Roth, and A. D. Guerci Association of Multiple Risk Factors and Insulin Resistance With Increased Prevalence of Asymptomatic Coronary Artery Disease by an Electron-Beam Computed Tomographic Study Arterioscler Thromb Vasc Biol, December 1, 2001; 21(12): 2051 - 2058. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T.-C. Su, J.-S. Jeng, K.-L. Chien, F.-C. Sung, H.-C. Hsu, and Y.-T. Lee Hypertension Status Is the Major Determinant of Carotid Atherosclerosis: A Community-Based Study in Taiwan Stroke, October 1, 2001; 32(10): 2265 - 2271. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. Kelly and A.D. Struthers Screening for left ventricular systolic dysfunction in patients with stroke, transient ischaemic attacks, and peripheral vascular disease QJM, June 1, 1999; 92(6): 295 - 297. [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||