The long-term prognostic value of the resting and postexercise ankle-brachial index.
BACKGROUND
Peripheral arterial disease is associated with a high incidence of cardiovascular mortality. Peripheral arterial disease can be detected by using the ankle-brachial index (ABI). This study assessed the prognostic value of the postexercise ABI in addition to the resting ABI on long-term mortality in patients with suspected peripheral arterial disease.


METHODS
In this prospective cohort study of 3209 patients (mean +/- SD age, 63 +/- 12 years; 71.1% male), resting and postexercise ABI values were measured and a reduction of postexercise ABI over baseline resting readings was calculated. The mean follow-up was 8 years (interquartile range, 4-11 years).


RESULTS
During follow-up, 1321 patients (41.2%) died. After adjusting for clinical risk factors, lower resting ABI values (hazard ratio per 0.10 lower ABI, 1.08; 95% confidence interval [CI], 1.06-1.10), lower postexercise ABI values (hazard ratio per 0.10 lower ABI, 1.09; 95% CI, 1.08-1.11), and higher reductions of ABI values over baseline readings (hazard ratio per 10% lower ABI, 1.12; 95% CI, 1.09-1.14) were significantly associated with a higher incidence of mortality. In patients with a normal resting ABI (n = 789), a reduction of the postexercise ABI by 6% to 24%, 25% to 55%, and greater than 55% was associated with a 1.6-fold (95% CI, 1.2-2.2), 3.5-fold (95% CI, 2.4-5.0), and 4.8-fold (95% CI, 2.5-9.1) increased risk of mortality, respectively.


CONCLUSIONS
Resting and postexercise ABI values are strong and independent predictors of mortality. A reduction of postexercise ABI over baseline readings can identify additional patients (who have normal ABI values at rest) at increased risk of subsequent mortality.
Feringa
Harm H H
HH
Department of Anesthesiology, Erasmus Medical Centre, Rotterdam, Netherlands.
Bax
Jeroen J J
JJ
van Waning
Virginie H
VH
Boersma
Eric
E
Elhendy
Abdou
A
Schouten
Olaf
O
Tangelder
Marco J
MJ
van Sambeek
Marc H R M
MH
van den Meiracker
Anton H
AH
Poldermans
Don
D
D000842:Ankle / Q000098:blood supply; D001794:Blood Pressure / Q000502:physiology*; D001916:Brachial Artery / Q000000981:diagnostic imaging / Q000503:physiopathology*; D018450:Disease Progression; D015444:Exercise / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007383:Intermittent Claudication / Q000000981:diagnostic imaging / Q000401:mortality / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D011379:Prognosis; D011446:Prospective Studies; D012146:Rest / Q000502:physiology*; D012307:Risk Factors; D015996:Survival Rate / Q000639:trends; D016909:Tibial Arteries / Q000000981:diagnostic imaging / Q000503:physiopathology*; D018608:Ultrasonography, Doppler