The ankle-brachial index in the elderly and risk of stroke, coronary disease, and death: the Framingham Study.
BACKGROUND
A low ankle-brachial index (ABI) is associated with an increased risk of death and cardiovascular disease. Limited data exist regarding the relation between a low ABI and stroke. We sought to examine the relation between a low ABI and stroke, coronary heart disease, and death in the elderly.


METHODS
We examined 251 men and 423 women with a mean age of 80 years who had a Framingham Study examination from 1994 to 1995. A low ABI was defined as less than 0.9. Persons were followed up for 4 years for occurrence of stroke or transient ischemic attack, coronary disease, and death. Cox proportional hazards models were used to assess the relation between a low ABI and each outcome after adjusting for age, sex, and prevalent cardiovascular disease.


RESULTS
A low ABI was detected in 20% of our sample. Only 18% of the participants with a low ABI reported claudication symptoms. One third of those with a normal ABI and 55% of those with a low ABI had cardiovascular disease at baseline. Results of multivariable Cox proportional hazards analysis demonstrated a statistically significant increase in the risk of stroke or transient ischemic attack in persons with a low ABI (hazards ratio, 2.0; 95% confidence interval, 1.1-3.7). No significant relation between a low ABI and coronary heart disease (hazards ratio, 1.2; 95% confidence interval, 0.7-2.1) or death (hazards ratio, 1.4; 95% confidence interval, 0.9-2.1) was observed.


CONCLUSIONS
A low ABI is associated with risk of stroke or transient ischemic attack in the elderly. These results need to be confirmed in larger studies.
Murabito
Joanne M
JM
National Heart, Lung, and Blood Institute's Framingham Heart Study, National Institutes of Health, Framingham, MA 01702-5827, USA.
Evans
Jane C
JC
Larson
Martin G
MG
Nieto
Kenneth
K
Levy
Daniel
D
Wilson
Peter W F
PW
D000368:Aged; D000369:Aged, 80 and over; D000842:Ankle; D001794:Blood Pressure; D001795:Blood Pressure Determination / Q000379:methods; D001916:Brachial Artery / Q000502:physiology*; D003327:Coronary Disease / Q000175:diagnosis* / Q000401:mortality / Q000503:physiopathology; D005260:Female; D006801:Humans; D007866:Leg / Q000098:blood supply / Q000502:physiology*; D008297:Male; D016491:Peripheral Vascular Diseases / Q000175:diagnosis* / Q000401:mortality / Q000503:physiopathology; D011237:Predictive Value of Tests; D012307:Risk Factors; D012720:Severity of Illness Index; D020521:Stroke / Q000175:diagnosis* / Q000401:mortality / Q000503:physiopathology