Chronic limb-threatening ischemia (CLTI) is a severe form of peripheral artery disease in which very poor blood flow in the arteries below the knee can cause rest pain, non-healing wounds, and even loss of the limb. It is often treated with endovascular therapy (EVT), a minimally invasive procedure that opens the blocked artery, but the artery frequently narrows or closes again afterward. These procedures are usually guided by X-ray pictures taken with dye (angiography). Intravascular ultrasound (IVUS) is an imaging tool that uses a small catheter inside the artery to give a more detailed view of the vessel, which may help doctors open it more completely. It is not yet clear whether adding IVUS improves results below the knee. This study is testing whether guiding treatment with IVUS plus angiography keeps the artery open better than angiography alone. Adults aged 18 or older with CLTI who are having endovascular therapy for a blocked artery below the knee may take part. Participants are assigned by chance to be treated with either both imaging methods or angiography alone, and are followed for 12 months. The main question is how well the treated artery stays open at 6 months; researchers will also compare repeat procedures, amputation, complications, wound healing, survival, and quality of life.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
DOUBLE
Enrollment
212
Endovascular therapy of the below-the-knee artery is guided by intravascular ultrasound (IVUS) imaging in addition to X-ray angiography, with IVUS used to assess the lesion, size and select devices, optimize treatment, and confirm the final result.
Endovascular therapy of the below-the-knee artery is guided by X-ray angiography with contrast dye alone, without the use of intravascular ultrasound, to assess the lesion, size and select devices, and judge the final result.
Chi Mei Medical Center
Tainan, Taiwan
National Taiwan University Hospital
Taipei, Taiwan
Shin Kong Wu Ho-Su Memorial Hospital
Taipei, Taiwan
Linkou Chang Gung Memorial Hospital
Taoyuan, Taiwan
Primary patency at 6 months
Freedom from clinically driven target lesion revascularization (CD-TLR), total occlusion of the target vessel, or binary restenosis of the target lesion. Binary restenosis is defined as a peak systolic velocity ratio \>2.0 on duplex ultrasound. Reported as the proportion of participants meeting all three criteria.
Time frame: 6 months after the index procedure
Major amputation of the study limb
Proportion of participants undergoing major (above-the-ankle) amputation of the study limb.
Time frame: 12 months
Major adverse limb events (MALE)
Proportion of participants with a major adverse limb event, defined as a composite of above-ankle amputation of the study limb, CD-TLR, or all-cause mortality.
Time frame: 12 months
Composite freedom from limb events
Proportion of participants free from all of the following: major amputation of the study limb, total occlusion of the target vessel, CD-TLR, and binary restenosis of the target lesion (peak systolic velocity ratio \>2.0 on duplex ultrasound).
Time frame: 12 months
Wound healing (Rutherford class 5 participants)
Wound healing rate, reported as the proportion of Rutherford class 5 participants with complete healing of the index wound.
Time frame: 1, 3, 6, 9, and 12 months
Time to complete wound healing (Rutherford class 5 participants)
Time to complete wound healing, reported as the time since the index procedure to complete healing of the index wound in Rutherford class 5 participants.
Time frame: From the index procedure to 12 months
Major adverse cardiovascular events (MACE)
Proportion of participants with a major adverse cardiovascular event, defined as a composite of non-fatal myocardial infarction, non-fatal stroke, or cardiovascular death, and each component reported individually.
Time frame: 12 months
Acute limb ischemia
Proportion of participants with an acute limb ischemia event in the study limb.
Time frame: 12 months
Limb-related mortality
Proportion of participants who die from a limb-related cause.
Time frame: 12 months
All-cause mortality
Proportion of participants who die from any cause.
Time frame: 12 months
Periprocedural complications
Proportion of participants with any periprocedural complication (e.g., dissection, perforation, distal embolization, access-site complication, or contrast-related event) related to the index procedure.
Time frame: During the index procedure through 30 days
Disagreement in imaging findings between angiography and IVUS
Proportion of treated lesions in which intravascular ultrasound (IVUS) findings differ from angiographic findings, as assessed by the core laboratory (including differences in vessel diameter, lesion length, degree of stenosis, plaque or calcium characterization, or identification of dissection or under-expansion).
Time frame: During the index procedure (Day 0)
Procedural success
Proportion of participants achieving procedural success, defined as successful revascularization of the target lesion with residual stenosis below the pre-specified threshold and no major periprocedural complication.
Time frame: During the index procedure (Day 0)
Procedure time
Total time of the index endovascular procedure, in minutes.
Time frame: During the index procedure (Day 0)
Contrast use
Total volume of iodinated contrast used during the index procedure, in milliliters.
Time frame: During the index procedure (Day 0)
Change in quality of life
Change from baseline in health-related quality of life, measured with one generic and two disease-specific instruments: 1. EQ-5D-5L (EuroQol 5-Dimension 5-Level): the descriptive system yields an index value ranging from less than 0 to 1 (1 = full health; higher scores = better quality of life), accompanied by the EQ Visual Analogue Scale scored 0 to 100 (higher = better health). 2. VascuQoL-6 (Vascular Quality of Life Questionnaire, 6-item): total score ranges from 6 to 24 (higher scores = better quality of life). 3. WIQ (Walking Impairment Questionnaire): score ranges from 0 to 100 (higher scores = better, i.e., less walking impairment).
Time frame: Baseline, 1, 3, 6 and 12 months
Change in ankle-brachial index
Change from baseline in ankle-brachial index (ABI)
Time frame: Baseline, 1, 3, 6, 9 and 12 months
Change in toe-brachial index
Change from baseline in toe-brachial index (TBI)
Time frame: Baseline, 1, 3, 6, 9 and 12 months
Change in transcutaneous oxygen pressure
Change from baseline in transcutaneous oxygen pressure (TcPO2)
Time frame: Baseline, 1, 3, 6, 9 and 12 months
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