Accuracy of Acceleration Time of Distal Arteries to Diagnose Severe Peripheral Arterial Disease

Abstract

Context: Ankle-brachial index (ABI) and toe-brachial index (TBI) are the recommended tests for the diagnosis of lower extremity peripheral artery disease (PAD) and the assessment of its severity, whereas Doppler ultrasound (DUS) is usually used to localize vascular lesions. However, the performance of DUS as an alternative to TBI and ABI measurement is unknown.

Objective: The goals were (i) to evaluate the correlation between DUS parameters of distal arteries of the lower extremities with TBI in patients with PAD; (ii) to evaluate the correlation between DUS parameters of distal arteries with ABI; and (iii) to assess the diagnostic accuracy of maximal acceleration time of pedal arteries to detect toe pressure ≤30 mmHg.

Methods: An observational retrospective study was conducted for 1 year on patients with the diagnosis of PAD on DUS. Demographic data, ABI, TBI, and DUS parameters of the dorsal pedis and lateral plantar arteries (DPA and LPA) were recorded.

Results: Seventy-seven patients with 88 limbs were included, aged 69 [interquartile range: 11 years] with 28.6% of diabetic patients. The highest acceleration time of either DPA or LPA (AT^max) was the most correlated to TBI on both univariate (r = -0.78, p < 0.0001) and multivariate analysis (p < 0.0001). DUS parameters had a weaker correlation with ABI. AT^max > 215 ms showed high diagnosis accuracy to a toe pressure of 30 mmHg or less [sensitivity of 86% [0.57-0.98] and negative predictive value of 97% [0.89-1.00]].

Conclusion: AT^max demonstrates a high correlation with TBI in patients with PAD, and high diagnostic accuracy for detection of critical limb ischemia. Based on these results, AT^max can represent the next step in evaluating PAD severity with DUS, in patients with advanced lower extremity PAD.

Keywords: Doppler ultrasound; acceleration time; ankle-brachial index (ABI); critical limb ischemia; peripheral arterial disease; toe-brachial index (TBI).

Figure 1

Technique and localization of duplex waveforms measurements of the dorsal pedis artery and lateral plantar artery. The (A,B) represent the parameters measured manually on different duplex waveforms: (A) corresponds to a triphasic waveform, classified N in the simplified Saint-Bonnet classification; and (B) is a monophasic attenuated (or “blunted”) waveform, classified as D-cf in the simplified Saint-Bonnet classification (10). Acceleration time is determined manually from the start of the systolic up-rise to the top of the systolic peak. (C) is an anatomic drawing of major pedal arteries. The grayed areas show the localization of the Doppler ultrasound recordings of the dorsal pedis artery and lateral plantar artery during the study.

Figure 2

Scatterplot and linear correlation of toe-brachial index with highest value of acceleration time between dorsalis pedis artery and lateral plantar artery. Correlation straight line is red-colored with blue-filled standard errors. R, Pearson's correlation coefficient; p, p-value.

Figure 3

Diagnosis accuracy of highest acceleration time of pedal arteries (AT^max) to detect toe pressure ≤30 mmHg (boxplot and area under ROC curve). ROC, receiver operating characteristic; msec, milliseconds; p, p-value; ns, non significant. *p < 0.05, *p < 0.01, **p < 0.001, ***p < 0.0001, ****p < 0.00001.