Change over time of the ankle brachial index

Objective: this study was designed to better understand the evolution of the ankle brachial Index (ABI) over time, so as to better inform clinical decision-making. Methods: patient selection included consecutive patients with at least two documented ABI Indexes obtained at Emory Healthcare between April 2005 and April 2013. Retrospective chart reviews were conducted on consecutive patients to assess ABI Index values, time between ABIs and whether revascularization had occurred between the two ABI measures. Qualifying patients included 76 patients with two ABIs and without a surgical intervention between the two measures. Results: the primary study outcome measure was the change in ABI per day. The average change in ABI per year was calculated as -0.012045. Extrapolating from these data, the estimated time in which meaningful deterioration (0.1) was found to be 8.3 years. Conclusion: these data demonstrate a change in ABI that is minimal and thus suggest that without intervening medical treatments that would change the ABI, routinely repeating this test is not warranted.