Abstract 9906: Endothelial Function is Impaired in Peripheral Arterial Disease With Borderline Ankle-Brachial Index
Introduction: Ankle-brachial index (ABI) measurement is useful for detecting peripheral arterial disease (PAD). Recently, several investigators have reported that an ABI value of 0.91 to 0.99 should be considered borderline and is associated with an increasing risk of cardiovascular disease. However, there is no information on the relationship between borderline ABI and endothelial function. The purpose of this study was to evaluate the relationship between ABI value and vascular function.
Methods and Results: We measured ABI and assessed vascular function by measurement of flow-mediated vasodilation (FMD) and nitroglycerine-induced vasodilation in 389 subjects who underwent health examinations (mean age, 58±18 years). Subjects were divided into 3 groups according to ABI (normal group: 1.00-1.40, borderline group: 0.91-0.99, abnormal group: ≤0.90 or >1.40). FMD were significantly smaller in the borderline group and abnormal group than in the normal group (3.6±1.9% and 3.1±2.8% vs. 5.1±2.7%, P=0.003 and P<0.001, respectively). There was no significant difference in vascular responses to nitroglycerine between the normal group and borderline group (13.3±5.7% vs. 11.2±4.8%, P=0.13). Vascular response to nitroglycerine was significantly higher in the normal ABI group than in the abnormal ABI group (13.3±5.7% vs. 9.0±6.4%, P<0.001). Borderline and abnormal ABI values were significantly associated with an increased odds ratio of the low tertile of FMD levels (Table 1). Multiple stepwise regression analysis for FMD revealed that age, gender, hypertension, diabetes mellitus, and borderline ABI independently remained associated with FMD (Table 2).
Conclusion: ABI value of 0.91-0.99 is associated with endothelial dysfunction, while vascular smooth muscle function is maintained in normal ranges. ABI examination is a simple and cost-effective method for obtaining the additional information on the grade of atherosclerosis beyond the assessment of PAD.
Author Disclosures: M. Kajikawa: None. Y. Higashi: None. T. Maruhashi: None. Y. Iwamoto: None. A. Iwamoto: None. T. Matsumoto: None. N. Oda: None. T. Hidaka: None. A. Nakashima: None. K. Noma: None. Y. Kihara: None.
- © 2014 by American Heart Association, Inc.