Ankle-brachial Index Decline Research Articles

Progression of Peripheral Arterial Disease Predicts Cardiovascular Disease Morbidity and Mortality

The purpose of this study was to examine the association of progressive versus stable peripheral arterial disease (PAD) with the risk of future cardiovascular disease (CVD) events. An independent association between PAD, defined by low values of the ankle-brachial index (ABI), and future CVD risk has been demonstrated. However, the prognostic significance of declining versus stable ABI has not been studied. We recruited 508 subjects (59 women, 449 men) from 2 hospital vascular laboratories in San Diego, California. ABI and CVD risk factors were measured at Visit 2 (1990 to 1994). ABI values from each subject's earliest vascular laboratory examination (Visit 1) were abstracted from medical records. Mortality and morbidity were tracked for 6 years after Visit 2 using vital statistics and hospitalization data. In multivariate models adjusted for CVD risk factors, very low (<0.70) and, in some cases, low (0.70 < or = ABI <0.90) Visit 2 ABIs were associated with significantly elevated all-cause mortality, CVD mortality, and combined CVD morbidity/mortality at 3 and 6 years. Decreases in ABI of more than 0.15 between Visit 1 and Visit 2 were significantly associated with an increased risk of all-cause mortality (risk ratio [RR]: 2.4) and CVD mortality (RR: 2.8) at 3 years, and CVD morbidity/mortality (RR: 1.9) at 6 years, independent of Visit 2 ABI and other risk factors. Progressive PAD (ABI decline >0.15) was significantly and independently associated with increased CVD risk. Patients with decreasing ABI may be candidates for more intensive cardiovascular risk factor management.

Hemostatic Factors, Inflammatory Markers, and Progressive Peripheral Atherosclerosis

The interplay between inflammatory and hemostatic mechanisms may play a crucial role in the development and progression of atherosclerosis. The authors evaluated the separate and joint associations of hemostatic and inflammatory variables on peripheral atherosclerotic progression in the Edinburgh Artery Study, a population cohort study of 1,592 men and women aged 55-74 years that started in 1987. Levels of fibrinogen, fibrin D-dimer, von Willebrand factor, tissue plasminogen activator antigen, factor VII, prothrombin fragment 1 + 2, urinary fibrinopeptide A, C-reactive protein, and interleukin-6 were measured at baseline. Arm and ankle blood pressures were measured, and atherosclerotic progression was assessed by computing ankle brachial index (ABI) at baseline (1,582 participants) and after 12 years of follow-up (813 participants). Fibrinogen (p = 0.05) and D-dimer (p < or = 0.05) were significantly associated with ABI change independently of baseline ABI and cardiovascular disease risk factors. However, these associations were no longer significant when analyses were adjusted for either C-reactive protein or interleukin-6. Moreover, subjects with higher levels of both D-dimer and interleukin-6 at baseline had the greatest ABI decline. In conclusion, fibrinogen and D-dimer, but not other hemostatic factors, were associated with progressive peripheral atherosclerosis. Since D-dimer and fibrinogen are acute phase reactants, these data support the hypothesis that inflammation is more related to atherosclerosis than is hypercoagulation.

Risk Factors for Declining Ankle-Brachial Index in Men and Women 65 Years or Older

An ankle-brachial index (ABI) of less than 0.9 is a noninvasive measure of lower extremity arterial disease and a predictor of cardiovascular events. Little information is available on longitudinal change in ABI or on risk factors for declining ABI in a community-based population. To assess risk factors for ABI decline, we studied 5888 participants in the Cardiovascular Health Study cohort (men and women 65 years or older). We measured ABI in 1992-1993 and again in 1998-1999. At baseline, we excluded individuals with an ABI less than 0.9, ABI greater than 1.4, or confirmed symptomatic lower extremity arterial disease (n = 823). The group with ABI decline included 218 participants with decline greater than 0.15 and to 0.9 or less. The comparison group comprised the remaining 2071 participants with follow-up ABI. The percentage of participants with ABI decline was 9.5% over 6 years of follow-up. The mean +/- SD decline was 0.33 +/- 0.12 in cases of ABI decline and 0.02 +/- 0.13 in non-cases. Independent predictors of ABI decline, reported as odds ratios, were age, 1.96 (95% confidence interval [CI], 1.42-2.71) for 75 to 84 years and 3.79 (95% CI, 1.36-10.5) for those older than 85 years compared with those younger than 75 years; current cigarette use, 1.74 (95% CI, 1.02-2.96); hypertension, 1.64 (95% CI, 1.18-2.28); diabetes, 1.77 (95% CI, 1.14-2.76); higher low-density lipoprotein cholesterol level, 1.60 (95% CI, 1.03-2.51), and lipid-lowering drug use 1.74 (95% CI, 1.05-2.89). Worsening lower extremity arterial disease, assessed as ABI decline, occurred in 9.5% of this elderly cohort over 6 years and was associated with modifiable vascular disease risk factors.

Natural history of claudication: Long-term serial follow-up study of 1244 claudicants

Objective: The purpose of this study was to delineate the natural history of claudication and determine risk factors for ischemic rest pain (IRP) and ischemic ulceration (IU) among patients with claudication. Methods: We prospectively collected data on 1244 men with claudication during a 15-year period, including demographics, clinical risk factors, and ankle-brachial index (ABI). We followed these patients serially with ABIs, self-reported walking distance (WalkDist), and monitoring for IRP and IU. We used Kaplan-Meier and proportional hazards modeling to find independent predictors of IRP and IU. Results: Mean follow-up was 45 months; statistically valid follow-up could be carried out for as long as 12 years. ABI declined an average of 0.014 per year. WalkDist declined at an average rate of 9.2 yards per year. The cumulative 10-year risks of development of IU and IRP were 23% and 30%, respectively. In multivariate analysis using several clinical risk factors, we found that only DM (relative risk [RR], 1.8) and ABI (RR, 2.2 for 0.1 decrease in ABI) predicted the development of IRP. Similarly, only DM (RR, 3.0) and ABI (RR, 1.9 for 0.1 decrease in ABI) were significant predictors of IU. Conclusion: This large serial study of claudication is, to our knowledge, the longest of its kind. We documented an average rate of ABI decline of 0.014 per year and a decline in WalkDist of 9.2 yards per year. Two clinical factors, ABI and DM, were found to be associated with the development of IRP and IU. Our findings may be useful in predicting the clinical course of claudication. (J Vasc Surg 2001;34:962-70.)