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.
Department of Anesthesiology, Erasmus Medical Centre, Rotterdam, Netherlands.
Harm H H
HH
Feringa
Jeroen J J
JJ
Bax
Virginie H
VH
van Waning
Eric
E
Boersma
Abdou
A
Elhendy
Olaf
O
Schouten
Marco J
MJ
Tangelder
Marc H R M
MH
van Sambeek
Anton H
AH
van den Meiracker
Don
D
Poldermans
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