Pedal acceleration time as a diagnostic and prognostic tool in peripheral artery disease: systematic review and...

Wound healing in chronic limb-threatening ischaemia in peripheral artery disease (PAD) remains clinically challenging. Accurate perfusion assessment may predict limb outcomes. Standard measures ankle-brachial index (ABI) and transcutaneous oxygen pressure have limitations. The ABI, the guideline-recommended first-line diagnostic tool, has well-recognised limitations in patients. Pedal acceleration time (PAT), measured by duplex ultrasound from onset to peak arterial systole in the pedal arteries, shows promise as a prognostic marker, though its diagnostic and prognostic performance has not been fully validated. This study aimed to perform a systematic review and meta-analysis evaluating PAT's diagnostic accuracy compared with ABI in detecting lower-limb ischaemia. Secondary objectives included assessing PAT's prognostic value for wound healing and amputation risk.

Three electronic databases MEDLINE, Scopus, and Web of Science, were systematically searched for studies evaluating PAT values and wound healing in PAD patients. Wound healing incidence and PAT-ABI correlations were pooled according to Preferred Reporting Items for Systematic reviews and Meta-Analyses of Diagnostic Test Accuracy studies (PRISMA-DTA) guidelines. Pooled diagnostic indices, including sensitivity, specificity, positive and negative likelihood ratios, and diagnostic odds ratio with 95% confidence intervals were calculated. Study quality was assessed using the National Heart, Lung, and Blood Institute (NHLBI) Study Quality Assessment Tool for observational cohort and cross-sectional designs.

Seventeen studies (1749 patients) were included as following: 8 cross-sectional, 1 observational prospective, 3 observational retrospective, 4 cohort (3 retrospective, 1 prospective), and 1 case-control study. PAT demonstrated good diagnostic accuracy with pooled 0.72 (95% CI 0.68-0.76) sensitivity, 0.84 (95% CI 0.79-0.88) specificity, 4.38 (95% CI 3.35-5.73) positive likelihood ratio, 0.25 (95% CI 0.19-0.33) negative likelihood ratio, and 14.85 (95% CI 10.02-22.01) diagnostic odds ratio, indicating robust discrimination compared to ABI. The selected studies, referring to the period 2019-2025, reported an association between higher PAT values and worse wound healing outcomes and increased amputation risk. Due to insufficient and non-standardised data, PAT's prognostic pooled analysis for wound healing was not feasible.

PAT accurately detected clinically significant lower-limb ischaemia compared to ABI. Faster PAT values correlated to higher ABI and favorable wound healing outcomes, whereas prolonged PAT indicated higher risk of non-healing wounds and major amputation. These results support PAT as a useful duplex-based complement to existing perfusion tests.