A narrative review of imaging misallocation in peripheral artery disease: a value-based medicine perspective.

BACKGROUND AND OBJECTIVE: Imaging for peripheral artery disease (PAD) is frequently misallocated: advanced cross-sectional studies are over-ordered for low-risk claudication, while high-risk chronic limb-threatening ischemia (CLTI) patients often receive no timely anatomic study. This narrative review summarizes current guideline pathways, quantifies real-world deviations, and identifies value-based remedies that better align modality and timing with clinical need. METHODS: Data sources were PubMed, professional-society websites [American College of Cardiology/American Heart Association (ACC/AHA), European Society for Vascular Surgery/European Society of Cardiology (ESVS/ESC), American College of Radiology (ACR)], and gray literature in a timeframe of January 2015-February 2025. Eligible items were English-language PAD imaging guidelines/consensus statements, registry/claims analyses, cohort/comparative studies, and cost/equity evaluations; single-case reports and non-vascular imaging were excluded. We extracted guideline-recommended diagnostic pathways, compared them with contemporary utilization and cost data, categorized misallocation and operational drivers. KEY CONTENT AND FINDINGS: Across four contemporary guidelines, the benchmark diagnostic sequence is physiologic testing with the ankle-brachial index or toe-brachial index (ABI/TBI), followed by duplex ultrasonography (DUS); when results would change management, computed tomography angiography (CTA) or magnetic resonance angiography (MRA) should be performed, with catheter-based digital subtraction angiography (DSA) reserved for intervention. Cross-sectional imaging increased three-fold in Medicare from 2011-2021, while first-line physiologic testing declined. Only 54% of CLTI patients receive CTA/MRA within 30 days, and each month of delay raises major amputation risk. Imaging access is poorest among minoritized, socio-economically disadvantaged, and rural groups, whereas supplier-induced demand amplifies scans in affluent settings. Misallocation exposes patients to avoidable radiation and contrast, strains radiology capacity, and contributes >US $4 billion in annual CLTI costs. Evidence shows guideline-aware clinical decision support can cut rarely-appropriate imaging by 10-40%, limb-salvage fast-track pathways reduce major amputations by ~30% and expanding sonographer staffing shifts after-hours demand away from CTA. CONCLUSIONS: PAD imaging is misaligned with value-based medicine: over-applied where benefit is marginal and under-applied where it is limb-saving. Implementing sequencing guardrails, decision-support tools, expedited CLTI workflows, and workforce remedies can rebalance utilization, enhance equity, and improve clinical and economic outcomes.