Usefulness of Postexercise Ankle-Brachial Index to Predict All-Cause Mortality

• Published in: The American journal of cardiology Vol. 107; no. 5; pp. 778 - 782
• Main Authors: Sheikh, Mobeen A., MD, Bhatt, Deepak L., MD, Li, Jianbo, PhD, Lin, Songhua, MS, Bartholomew, John R., MD
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01-03-2011; Elsevier; Elsevier Limited
• Subjects: Adult; Aged; Ankle - blood supply; Biological and medical sciences; Blood pressure; Blood Pressure - physiology; Brachial Artery - diagnostic imaging; Brachial Artery - physiopathology; Cardiology; Cardiology. Vascular system; Cardiovascular; Cardiovascular disease; Cause of Death; Disease Progression; Exercise; Exercise - physiology; Female; Humans; Intermittent Claudication - diagnostic imaging; Intermittent Claudication - mortality; Intermittent Claudication - physiopathology; Male; Medical sciences; Middle Aged; Mortality; Ohio - epidemiology; Predictive Value of Tests; Prognosis; Retrospective Studies; Risk Factors; Tibial Arteries - diagnostic imaging; Tibial Arteries - physiopathology; Ultrasonography, Doppler; United States > US; Ankle; Prognosis; Mortality; Index; Circulatory system; Cardiology; Predictive factor
• ISSN: 0002-9149; 1879-1913
• DOI: 10.1016/j.amjcard.2010.10.060

Peripheral arterial disease predicts future cardiovascular events and all-cause mortality. Conventional methods of assessment might underestimate its true prevalence. We sought to determine whether a postexercise ankle-brachial index (ABI), not only improved peripheral arterial disease detection, but also independently predicted death. This was an observational study of consecutive patients referred for ABI measurement before and after the fixed-grade treadmill or symptom-limited exercise component to a noninvasive vascular laboratory from January 1990 to December 2000. The subjects were classified into 2 groups. Group 1 included patients with an ABI of ≥0.85 before and after exercise, and group 2 included patients with a normal ABI at rest but <0.85 after exercise. A total of 6,292 patients underwent ABI measurements with exercise during the study period. Propensity score matching of the groups was performed to minimize observational bias. Overall mortality, as determined using the United States Social Security death index, was the end point. The 10-year mortality rate of groups 1 and 2 was 32.7% and 41.2%, respectively. An abnormal postexercise ABI result independently predicted mortality (hazard ratio 1.3, 95% confidence interval 1.07 to 1.58, p = 0.008). Additional independent predictors of mortality were age, male gender, diabetes, and hypertension. After the exclusion of patients with a history of cardiovascular events, the predictive value of an abnormal postexercise ABI remained statistically significant (hazard ratio 1.67, 95% confidence interval 1.29 to 2.17, p <0.0001). In conclusion, our results have shown that the postexercise ABI is a powerful independent predictor of all-cause mortality and provides additional risk stratification beyond the ABI at rest.