Point of care ankle pulse waveform: A biomarker for abdominal aortic aneurysm?

Abstract

To explore the potential relationship between the presence of abdominal aortic aneurysm and point of care ankle brachial index acquired posterior tibial artery Doppler waveform to inform on a potential novel biomarker of abdominal aortic aneurysm presence. Abdominal aortic aneurysm presence and posterior tibial artery waveform acquired at time of routine point of care ankle brachial index were determined in 182 patients from an abdominal aortic aneurysm evaluation vascular outpatient clinic. Multivariate technical random forest analysis and logistical regression analysis assessed the outcome of abdominal aortic aneurysm presence and included the independent variables of monophasic initial posterior tibial artery waveform and known abdominal aortic aneurysm risk factors. Technical random forest analysis produced a model with an accuracy of 0.59. Initial waveform phase was the most important variable included in the model. Logistical regression analysis revealed a statistically significant negative association between initial monophasic posterior tibial artery waveform and abdominal aortic aneurysm presence in patients with ankle brachial index > 0.9. Leave one out cross validation analysis produced a bias-corrected prediction error value of 0.22. No robust association between abdominal aortic aneurysm and point of care ankle brachial index acquired posterior tibial artery waveform was found, suggesting that monophasic posterior tibial artery waveform alone may not be a biomarker of abdominal aortic aneurysm presence.