T he ankle-brachial index (ABI) is the ratio of the systolic blood pressure (SBP) measured at the ankle to that measured at the brachial artery. Originally described by Winsor 1 in 1950, this index was initially proposed for the noninvasive diagnosis of lower-extremity peripheral artery disease (PAD). 2,3 Later, it was shown that the ABI is an indicator of atherosclerosis at other vascular sites and can serve as a prognostic marker for cardiovascular events and functional impairment, even in the absence of symptoms of PAD. 4 -6 Rationale for Standardization of the ABIThe current lack of standards for measurement and calculation of the ABI leads to discrepant results with significant impact from clinical, public health, and economic standpoints. Indeed, the estimated prevalence of PAD may vary substantially according to the mode of ABI calculation. [7][8][9] In a review of 100 randomly selected reports using the ABI, multiple variations in technique were identified, including the position of the patient during measurement, the sizes of the arm and leg cuffs, the location of the cuff on the extremity, the method of pulse detection over the brachial artery and at the ankles, whether the arm and ankle pressures were measured bilaterally, which ankle pulses were used, and whether a single or replicate measures were obtained. 10 There is controversy about what ABI threshold should be used to diagnose PAD. The ABI threshold most commonly used is Յ0.90 based on studies reporting Ͼ90% sensitivity and specificity to detect PAD compared with angiography. 2,3 These studies were limited in that they included mostly older white men with PAD or who were at high risk for PAD and compared them with a younger healthy group. A recent metaanalysis of 8 studies of diverse populations, including diabetic patients, confirmed a high specificity but lower sensitivity (at best Ͻ80%) than that reported in earlier studies. 11 Similar to other vascular markers such as carotid intimamedia thickness 12 or coronary artery calcium score, 13 standardization of the techniques used to measure the ABI and the calculation and interpretation of its values is necessary. Aims and ScopeThe goals for this document are to provide a comprehensive review of the relevant literature on the measurement of the The American Heart Association makes every effort to avoid any actual or potential conflicts of interest that may arise as a result of an outside relationship or a personal, professional, or business interest of a member of the writing panel. Specifically, all members of the writing group are required to complete and submit a Disclosure Questionnaire showing all such relationships that might be perceived as real or potential conflicts of interest.This statement was approved by the American Heart Association Science Advisory and Coordinating Committee on September 10, 2012. A copy of the document is available at http://my.americanheart.org/statements by selecting either the "By Topic" link or the "By Publication Date" link. To purchase additional repri...

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Background-Our aim was to assess the mortality and vascular morbidity risk of elderly individuals with asymptomatic versus symptomatic peripheral artery disease (PAD) in the primary care setting. Methods and Results-This prospective cohort study included 6880 representative unselected patients Ն65 years of age with monitored follow-up over 5 years. According to physician diagnosis, 5392 patients had no PAD, 836 had asymptomatic PAD (ankle brachial index Ͻ0.9 without symptoms), and 593 had symptomatic PAD (lower-extremity peripheral revascularization, amputation as a result of PAD, or intermittent claudication symptoms regardless of ankle brachial index). The risk of symptomatic compared with asymptomatic PAD patients was significantly increased for the composite of all-cause death or severe vascular event (myocardial infarction, coronary revascularization, stroke, carotid revascularization, or lower-extremity peripheral vascular events; hazard ratio, 1.48; 95% confidence interval, 1.21 to 1.80) but not for all-cause death alone (hazard ratio, 1.13; 95% confidence interval, 0.89 to 1.43), all-cause death/myocardial infarction/stroke (excluding lower-extremity peripheral vascular events and any revascularizations; hazard ratio, 1.18; 95% confidence interval, 0.92 to 1.52), cardiovascular events alone (hazard ratio, 1.20; 95% confidence interval, 0.89 to 1.60), or cerebrovascular events alone (hazard ratio, 1.33; 95% confidence interval, 0.80 to 2.20). Lower ankle brachial index categories were associated with increased risk. PAD was a strong factor for the prediction of the composite end point in an adjusted model. Conclusions-Asymptomatic PAD diagnosed through routine screening in the offices of primary care physicians carries a high mortality and/or vascular event risk. Notably, the risk of mortality was similar in symptomatic and asymptomatic patients with PAD and was significantly higher than in those without PAD. In the primary care setting, the diagnosis of PAD has important prognostic value.

This study evaluated the efficacy and safety of intramuscular administration of NV1FGF, a plasmid-based angiogenic gene delivery system for local expression of fibroblast growth factor 1 (FGF-1), versus placebo, in patients with critical limb ischemia (CLI). In a double-blind, randomized, placebo-controlled, European, multinational study, 125 patients in whom revascularization was not considered to be a suitable option, presenting with nonhealing ulcer(s), were randomized to receive eight intramuscular injections of placebo or 2.5 ml of NV1FGF at 0.2 mg/ml on days 1, 15, 30, and 45 (total 16 mg: 4 x 4 mg). The primary end point was occurrence of complete healing of at least one ulcer in the treated limb at week 25. Secondary end points included ankle brachial index (ABI), amputation, and death. There were 107 patients eligible for evaluation. Improvements in ulcer healing were similar for use of NV1FGF (19.6%) and placebo (14.3%; P = 0.514). However, the use of NV1FGF significantly reduced (by twofold) the risk of all amputations [hazard ratio (HR) 0.498; P = 0.015] and major amputations (HR 0.371; P = 0.015). Furthermore, there was a trend for reduced risk of death with the use of NV1FGF (HR 0.460; P = 0.105). The adverse event incidence was high, and similar between the groups. In patients with CLI, plasmid-based NV1FGF gene transfer was well tolerated, and resulted in a significantly reduced risk of major amputation when compared with placebo.

Patients with a low ABI (PAD), who can be readily identified in a primary care setting, have a substantially increased risk of death and severe vascular events. Patients with an ABI between 1.1 and 0.9 should be considered and followed up as borderline PAD cases. Particular attention should be paid to patients with PAD and previous vascular events, as their risk is markedly increased.

Endovascular therapy is a rapidly evolving field for the treatment of patients with peripheral arterial disease, and a magnitude of studies reporting on various modern revascularization concepts have been recently published. Thus, studies assessing the efficacy of endovascular therapy of peripheral arteries do not operate with uniformly defined endpoints, rendering a direct comparison of studies difficult. The purpose of this consensus statement is to highlight differences in the terminology used in the current literature and to propose some standardized criteria that must be considered when reporting results of endovascular revascularization for chronic ischaemia of lower limb arteries.

LAP is the superior method of calculating ABI to identify PAD. This result is of great interest for epidemiologic studies applying ABI measurements to detect PAD and assessing patients' cardiovascular risk.

International audienceThe reliability of ankle—brachial index (ABI) measurements performed by different observer groups in primary care has not yet been determined. The aims of the study were to provide precise estimates for all effects influencing the variability of the ABI (patients' individual variability, intra- and inter-observer variability), with particular focus on the performance of different observer groups. Using a partially balanced incomplete block design, 144 unselected individuals aged ≥ 65 years underwent double ABI measurements by one vascular surgeon or vascular physician, one family physician and one nurse with training in Doppler sonography. Three groups comprising a total of 108 individuals were analyzed (only two with ABI < 0.90). Errors for two repeated measurements for all three observer groups did not differ (experts 8.5%, family physicians 7.7%, and nurses 7.5%, = 0.39). There was no relevant bias among observer groups. Intra-observer variability expressed as standard deviation divided by the mean was 8%, and inter-observer variability was 9%. In conclusion, reproducibility of the ABI measurement was good in this cohort of elderly patients who almost all had values in the normal range. The mean error of 8—9% within or between observers is smaller than with established screening measures. Since there were no differences among observers with different training backgrounds, our study confirms the appropriateness of ABI assessment for screening peripheral arterial disease (PAD) and generalized atherosclerosis in the primary case setting. Given the importance of the early detection and management of PAD, this diagnostic tool should be used routinely as a standard for PAD screening. Additional studies will be required to confirm our observations in patients with PAD of various severities