Comparative study of pressure (ankle-brachial pressure index) and flow (strain gauge plethysmography and reactive hyperaemia) measurements in diagnosis of peripheral arterial disease in patients with severe aortic stenosis

Background The measurement of the ankle-brachial pressure index is a straightforward method for the detection of peripheral disease in the lower limbs. Only a few old studies with small numbers of patients have been conducted comparing the gold standard, ankle-brachial pressure index measurement, with strain gauge plethysmography and reactive hyperaemia for detecting peripheral arterial disease. The purpose of this study was to evaluate the feasibility and accuracy of strain gauge plethysmography values compared with the Doppler ultrasound method, ankle-brachial pressure index, in the assessment of peripheral arterial disease, especially in patients with severe aortic stenosis. Methods 221 ankle-brachial pressure index measurements and strain gauge plethysmography measurements of patients with suspected peripheral arterial disease, diagnosed peripheral arterial disease with or without aortic stenosis were compared. Results Irrespective of aortic stenosis in patients with and without peripheral arterial disease, the resting arterial blood flow was within the normal range. In patients with aortic stenosis, the time-to-peak flow couldn’t detect peripheral arterial disease and was found to be a false negative. In patients without aortic stenosis, time-to-peak flow correlated well with the ankle-brachial pressure index for detecting peripheral arterial disease. Peak flow at 5 seconds was the one of the flow values that correlated with ankle-brachial pressure index and detected peripheral arterial disease in patients with and without aortic stenosis. Conclusion Peak flow at 5 seconds is one of flow value that correlated well with ankle-brachial pressure index in detecting peripheral arterial disease in patients with and without aortic stenosis. Detection of peripheral arterial disease in patients with severe aortic stenosis seems to be less sensitive with flow measurements than with ankle-brachial pressure index.