p.16 抽出テキスト

CLINICAL STATEMENTS AND GUIDELINES

June 11, 2024 Circulation. 2024;149:e1313–e1410. DOI: 10.1161/CIR.0000000000001251 e1328

presenting with abnormal ABIs.30 A TBI of ≤0.70 is considered abnormal and allows for diagnosis of PAD, whereas absolute toe pressures <30 mm Hg are reflective of severe ischemia and are associated with major amputation and decreased likelihood of wound healing.13,16,31,32 In addition to toe pressures and TBI, an abnormal continuouswave Doppler or photoplethysmographic waveform obtained from the base of the great toe further supports the diagnosis of PAD in the patient with suspected CLTI.33 TcPO2 and SPP are other testing modalities that can be used for perfusion assessment. A TcPO2 of >30 mm Hg or an SPP of >40 mm Hg can predict wound healing.34–37 Perfusion assessment measures (ie, TBI with waveforms, TcPO2, SPP) are obtained in a warm room to prevent arterial vasoconstriction in response to the cold. For patients with nonhealing lower extremity wounds with normal perfusion assessment, alternative diagnoses should be considered (Table 8). 10.	 In patients with nonhealing wounds or gangrene

in whom the diagnosis of CLTI has been established, additional perfusion assessments including toe pressure/TBI, TcPO2, and SPP have shown the ability to assess local perfusion and determine wound-healing potential and risk for amputation.32–35,37 Laser Doppler flowmetry and laser speckle imaging are emerging technologies with potential for assessing perfusion in limbs with wounds, but larger prospective studies are required for their validation as useful primary perfusion assessment tools.63,64 Similarly, pedal acceleration time has been correlated with the ABI and clinical presentation of PAD, and improvement in the pedal acceleration time (180 ms) after revascularization in patients with CLTI has been associated with limb salvage in a single-center study.65,66 Development of additional tools for perfusion assessment and prediction of wound-healing potential in the setting of CLTI is an area of ongoing investigation with new modalities, such as spatial frequency domain imaging, currently under investigation.63,67,68

3.2 Imaging for PAD

Recommendations for Imaging for PAD Referenced studies that support the recommendations are summarized in the Online Data Supplement. COR LOE Recommendations

1 B-NR 1 In patients with functionally limiting claudication with

inadequate response to GDMT (including structured exercise) for whom revascularization is being considered, duplex ultrasound, computed tomography angiography (CTA), magnetic resonance angiography (MRA), or catheter angiography of the lower extremities is useful for assessment of anatomy and severity of disease and to determine potential revascularization strategy.1–4 1 B-NR 2.	 In patients with CLTI, duplex ultrasound, CTA, MRA,

or catheter angiography is useful to determine revascularization strategy.1–3,5,6

2b C-EO 3 In patients with suspected PAD (ie, potential signs

and/or symptoms) with inconclusive ABI and physiological testing, noninvasive imaging with duplex ultrasound, CTA, or MRA may be considered to establish the diagnosis of PAD.

3: Harm B-NR 4 In patients with a confirmed diagnosis of PAD in whom

revascularization is not being considered, CTA, MRA, or catheter angiography should not be performed solely for anatomic assessment.7–10

Synopsis Arterial imaging studies are generally obtained when revascularization is being considered but may also be used when there is clinical suspicion of PAD and the ABI and physiological tests are inconclusive (Figure 2). Arterial imaging can be accomplished by several modalities. Duplex ultrasound is noninvasive and does not require the use of radiation or contrast to image arteries, although dedicated and trained technical and medical personnel are required to perform and interpret, along with dedicated time to image all of the arteries in the lower limbs.4 CTA and MRA are noninvasive cross-sectional imaging modalities that provide greater detail of the anatomy and severity of PAD and are less personnel-dependent; however, they are associated with potential risks related to contrast or (in the case of CTA) radiation exposure.7–10 Catheter angiography is associated with risks of radiation exposure and contrast as well as arterial injury and bleeding from invasive catheter placement, and it is usually restricted to the more severe presentations of PAD where revascularization is being considered and the benefits outweigh the risks of these complications.

Recommendation-Specific Supportive Text

1 Preprocedural imaging is used to plan a potential

revascularization strategy for patients with functionally limiting claudication for whom response to GDMT (including structured exercise) is inadequate and revascularization is being considered. Such imaging provides an assessment of vascular access sites, location of stenotic lesions or occlusions, and assessment of the feasibility of and modality for revascularization. Duplex ultrasound, CTA, and MRA have good sensitivity and specificity for the detection of PAD stenotic and/or occlusive lesions compared with catheter-based angiography,1–4 and the choice of imaging modality is individualized based on patient and imaging modality-based factors as well as local availability of resources. Duplex ultrasound is technologist-dependent, and CTA

Recommendations for Imaging for PAD (Continued) COR LOE Recommendations

Downloaded from http://ahajournals.org by on October 7, 2026