Accuracy of maximal acceleration time of pedal arteries to diagnose critical limb-threatening ischemia

Introduction: Maximal acceleration time of distal arteries of the foot (AT^max) is correlated to ankle-brachial index (ABI) and toe-brachial index (TBI), and seems very promising in diagnosing severe peripheral artery disease (PAD) and especially critical limb-threatening ischemia (CLTI). Our goal was to confirm the cut-off value of 215 ms to predict a toe pressure (TP) ⩽ 30 mmHg.

Methods: A 4-month retrospective study was conducted on patients addressed for suspicion of PAD. Demographic data, ABI, TBI, and Doppler ultrasound scanning parameters of the dorsal pedis and lateral plantar arteries (DPA and LPA) were recorded.

Results: A total of 137 patients with 258 lower limbs were included. AT^max was highly correlated to TBI (r = -0.89, p < 0.001). With the cut-off value of 215 ms, AT^max was effective to diagnose TP ⩽ 30 mmHg with a sensitivity of 93% [95% CI 77-99], a specificity of 96% [95% CI 92-98], a positive predictive value of 73% [95% CI 56-86], a negative predictive value of 99% [95% CI 97-100], and an area under the receiver operating characteristics curve of 0.99 [95% CI 0.98-1.00]. AT^max also showed promising results to rule out PAD in healthy patients.

Conclusion: AT^max is a reliable diagnostic tool to diagnose low TP and could be a new easily performed hemodynamic criterion for diagnosis of CLTI.