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Severe carotid artery stenosis (CAS) increases the risk of cerebrovascular disease and sometimes requires revascularization to prevent the recurrence of stroke or transient ischemic attacks (TIAs) [1]. The Ministry of Health of the People's Republic of China recently initiated a screening and prevention project for stroke including a screening for extracranial CAS in high-risk population. A better understanding of the prevalence of CAS in various regions of China is warranted to ensure an appropriate allocation of medical resources. Previous studies have found a relative high prevalence of CAS among patients with cerebrovascular disease in northern China [2, 3]; however, the prevalence of CAS in southern China is unknown. Thus, we performed a retrospective, cross-sectional study on 862 inpatients that presented with stroke or TIA at a hospital in southern China and underwent computed tomography angiography (CTA) or contrast enhanced-magnetic resonance angiography (CE-MRA) to determine the prevalence of severe CAS of bilateral carotid arteries. Of 862 patients, 3·7% had CAS between 50% and 69%, 3·1% had CAS between 70% and 99%, and 2·6% had complete occlusion (Table 1). Furthermore, 43 (5·0%) patients had 70–99% symptomatic stenosis ipsilateral to the ischemic hemisphere. The side of more severe stenosis was counted for bilateral carotid stenosis patients (n = 56).

Table 1. Demographics of patients and disease characteristics
CharacteristicUnderwent CTA/MRA (n = 862)
  1. Age is presented by mean and standard deviation; NIHSS is presented by median and interquartile range; and other variables are presented by count and percentage.

  2. *The side of more severe stenosis was counted in case of bilateral carotid stenosis.

  3. CAS, carotid artery stenosis; CE, cadiogenic embolism; CTA, computed tomography angiography; MRA, magnetic resonance angiography; MRS, modified Rankin Scale; NIHSS, the NIH stroke scale; TIA, transient ischemic attack; TOAST, trial of ORG 10172 in acute stroke treatment.

Age (years)64·6 ± 13·4
Male594 (68·9%)
Initial NIHSS3·0 (2·0, 6·0)
MRS ≥ 3330 (38·3%)
Hypertension564 (65·4%)
Diabetes mellitus210 (24·4%)
Hyperlipidemia388 (45·0%)
Hyperhomocysteinemia303 (35·2%)
History of TIA/ischemic stroke166 (19·3%)
Coronary artery disease77 (8·9%)
Smoking344 (39·9%)
Alcohol consumption222 (25·8%)
Family history of TIA/ischemic stroke108 (12·5%)
Family history of hypertension168 (19·5%)
TOAST in CE85 (9·9%)
Severity of carotid artery stenosis* 
No CAS673 (78·1%)
1–49%108 (12·5%)
50–69%32 (3·7%)
70–99%27 (3·1%)
Complete occlusion22 (2·6%)
Symptomatic stenosis, >70%43 (5·0%)

In one study, the prevalence of CAS (>50% stenosis) in Hong Kong Chinese patients with stroke was reported to be 21% [4]. In northern China, specifically Beijing, it was reported that 17·3% of patients with ischemic stroke had CAS >50% [2], and 39·4% of patients with stroke or TIA had CAS >70% [3]. Thus, the prevalence of severe CAS is very much lower in southern vs. northern China, possibly due to the difference of living and die habit or genetic background. Accordingly, large-scale screening for extracranial CAS in people at low risk in southern China may not be necessary. B ultrasound screening, rather than expensive and contrast-needed screening (i.e., CTA, CE-MRA, or digital substraction angiography (DSA)) that are used extensively in Chinese large hospitals for all stroke patients, could be used for high-risk population in southern China.

Acknowledgement

This work was supported by grants from the National Natural Science Foundation of China [No. 81070914, 81271302 to J.R. Liu; No. 81200941 to J.J. Su]; and a grant from the “New One Hundred Talents Program” from the Shanghai Jiao Tong University School of Medicine [2012, J.R. Liu].

References

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  2. References
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    Song G, Wang Y, Dong K, Jiang W, Du B, Chen Q. The distribution of cerebral artery stenosis in patients with ischemic cerebrovascular disease. Chin J Geritar Heart Brain Vessel Dis 2008; 10:680683 [in Chinese].
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