Associations of ankle-brachial index with clinical coronary heart disease, stroke and preclinical carotid and popliteal atherosclerosis:

TLDR

The resting ankle‑brachial index (ABI) is a non‑invasive method to assess lower extremity arterial patency and screen for peripheral occlusive arterial disease. The study aimed to determine how ABI associates with clinical coronary heart disease, stroke, and preclinical carotid and popliteal atherosclerosis in 15,106 middle‑aged adults from the ARIC baseline. Analyses were conducted on baseline data (1987‑1989) from the ARIC Study, evaluating associations between ABI and clinical CHD, stroke/TIA, carotid plaque, and intima‑media thickness of carotid and popliteal arteries. Individuals with ABI < 0.90 had roughly twice the odds of prevalent CHD and more than four times the odds of stroke/TIA compared with ABI > 0.90, and also showed higher prevalence of carotid plaque and increased intima‑media thickness; these associations weakened after adjustment for LDL, smoking, hypertension, and diabetes, underscoring that low ABI reflects generalized atherosclerosis.

Abstract

The resting ankle-brachial index (ABI) is a non-invasive method to assess the patency of the lower extremity arterial system and to screen for the presence of peripheral occlusive arterial disease. To determine how the ABI is associated with clinical coronary heart disease (CHD), stroke, preclinical carotid plaque and far wall intimal-medial thickness (IMT) of the carotid and popliteal arteries, we conducted analyses in 15 106 middle-aged adults from the baseline examination (1987–1989) of the Atherosclerosis Risk in Communities (ARIC) Study. The prevalence of clinical CHD, stroke/transient ischemic attack (TIA) and preclinical carotid plaque increased with decreasing ABI levels, particularly at those of <0.90. Individuals with ABI<0.90 were twice as likely to have prevalent CHD as those with ABI>0.90 (age-adjusted odds ratio (OR) ranging from 2.2 (95% CI: 1.0–5.1) in African-American men to 3.3 (95% CI: 2.1–5.0) in white men). Men with ABI<0.90 were more than four times as likely to have stroke/TIA as those with ABI>0.90 (age-adjusted OR: 4.2 (95% CI: 1.8–9.5) in African-American men and 4.9 (95% CI: 2.6–9.0) in white men). In women the association was weaker and not statistically significant. Among those free of clinical cardiovascular disease, individuals with ABI≤0.90 had statistically significantly higher prevalence of preclinical carotid plaque compared to those with ABI>0.90 (age-adjusted ORs ranging from 1.5 (95% CI: 1.0–1.9) in white women to 2.6 (95% CI: 1.06.6) in african-american men). The ABI was also inversely associated with far wall IMT of the carotid arteries (in both men and women) and the popliteal arteries (in men only). The associations of ABI with clinical CHD, stroke, preclinical carotid plaque and IMT of the carotid and popliteal arteries were attenuated and often not statistically significant after further adjustment for LDL cholesterol, cigarette smoking, hypertension and diabetes. These data demonstrate that low ABI levels, particularly those of <0.90, are indicative of generalized atherosclerosis.