Associations of ankle-brachial index (ABI) with cerebral arterial disease and vascular events following ischemic stroke.
OBJECTIVE
Low ankle-brachial index (ABI), indicative of peripheral arterial disease (PAD), is a risk factor for stroke. ABI has been shown to be associated with cerebral arterial disease and prognosis following stroke. We studied the associations of the degree of ABI lowering with extracranial carotid disease (ECD), intracranial large artery disease (ICLAD), and subsequent vascular events in a prospective cohort of acute ischemic stroke patients.


METHODS
ABI, extracranial and intracranial cerebral arteries were assessed in a blinded manner. ABI was categorized into 0.9-1.3 (normal), 0.8-0.89 (mildly lowered) and <0.8 (severely lowered). Follow-up data at 1 year were obtained from standardized telephone interviews and verified with medical records.


RESULTS
Among the 1311 patients, 73% had normal ABI, 13% had ABI 0.8-0.89 and 13% had ABI <0.8. Compared to patients with normal ABI, those with ABI<0.8 had higher prevalence of severe ECD (15% vs. 5%, p = 0.006) and ICLAD (72% vs. 48%, p = 0.003), even after adjustment for age, gender, hypertension, diabetes, hyperlipidemia, smoking, ischemic heart disease and atrial fibrillation (severe ECD p < 0.001, ICLAD p < 0.001). At 1 year, patients with ABI <0.8 had a higher incidence of composite vascular events (19% vs. 11%, p = 0.02), stroke (15% vs. 10%, p = 0.06) and myocardial infarction (4% vs. 2%, p = 0.07) than patients with normal ABI.


CONCLUSIONS
Among ischemic stroke patients, large cerebral arterial disease and incidence of subsequent vascular events at 1 year were associated with severe ABI lowering <0.8, but not with mild ABI lowering (0.8-0.89).
Singapore General Hospital Campus, National Neuroscience Institute, Department of Neurology, Singapore General Hospital, Singapore.
Jennifer Justice F
JJ
Manzano
Deidre A
DA
De Silva
Jose Leonard R
JL
Pascual
Hui-Meng
HM
Chang
Meng-Cheong
MC
Wong
Christopher P L H
CP
Chen
D000368:Aged; D055109:Ankle Brachial Index; D002545:Brain Ischemia / Q000000981:diagnostic imaging / Q000453:epidemiology*; D016893:Carotid Stenosis / Q000000981:diagnostic imaging / Q000453:epidemiology*; D002539:Cerebral Arterial Diseases / Q000000981:diagnostic imaging / Q000453:epidemiology*; D005260:Female; D006801:Humans; D015994:Incidence; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D058729:Peripheral Arterial Disease / Q000175:diagnosis* / Q000453:epidemiology*; D011237:Predictive Value of Tests; D015995:Prevalence; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index; D012846:Singapore / Q000453:epidemiology; D020521:Stroke / Q000000981:diagnostic imaging / Q000453:epidemiology*; D013997:Time Factors; D018615:Ultrasonography, Doppler, Color; D017585:Ultrasonography, Doppler, Transcranial