Validation of Pedal Acceleration Time for the Assessment of Perfusion in Patients with Chronic Limb Threatening Ischemia.

Objective: Accurate hemodynamic assessment of perfusion is critical in managing patients with chronic limb threatening ischemia (CLTI). Traditional methods such as ankle-brachial index (ABI) and toe pressures (TP) may be inadequate due to arterial calcification and toe amputations. Pedal acceleration time (PAT), a novel technique, aims to address these limitations. The objective of this study was to further validate this technique.

Methods: A retrospective review was conducted in patients with CLTI who underwent PAT measurement during clinical evaluations. PAT measurements were correlated with ABI, TP, pedal calcification, limb staging (WIfI), and major amputation. Correlations were compared between highest, lowest, and average PAT values, as well as occlusive and angiosomal patterns to identify predictive thresholds.

Results: 41 patients with 51 limbs were included. Highest PAT positively correlated with WIfI wound grade (p=0.04). Additionally, highest and average PAT values demonstrated significant correlations with ischemia grade based on TP (p<0.001 for both). Lowest also correlated with TP but less strongly. Incompressible ankle pressures were present in 61% of patients; highest PAT did not correlate with ABI (p=0.08). Average PAT was higher in the dorsal metatarsal and medial plantar arteries of patients with hallux or 2^nd digit wounds (p=0.04) and arcuate and deep plantar arteries of patients with digits 3-5 wounds (p=0.02) compared to those without wounds in the respective angiosomes.

Conclusions: PAT is a valuable adjunct for assessing perfusion in patients with calcified, incompressible ankle vessels, particularly when TP is unavailable. Highest and average PAT values are the most predictive of ischemia severity, and PAT measurements correlate anatomically with wound location.