IVUS Guidance in BTK Interventions

Official title

Intravascular Ultrasound IMaging vs Angiography-Guided EVT in Below-the-Knee Arteries

Overview

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.

Interventions

• Procedure Intravascular ultrasound-guided EVT
  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.
• Procedure Angiography-guided EVT
  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.

Primary outcome measures

• Primary patency at 6 months [Time frame: 6 months after the index procedure]

Secondary outcome measures (12)

• Major amputation of the study limb [Time frame: 12 months]
• Major adverse limb events (MALE) [Time frame: 12 months]
• Composite freedom from limb events [Time frame: 12 months]
• Wound healing (Rutherford class 5 participants) [Time frame: 1, 3, 6, 9, and 12 months]
• Time to complete wound healing (Rutherford class 5 participants) [Time frame: From the index procedure to 12 months]
• Major adverse cardiovascular events (MACE) [Time frame: 12 months]
• Acute limb ischemia [Time frame: 12 months]
• Limb-related mortality [Time frame: 12 months]
• All-cause mortality [Time frame: 12 months]
• Periprocedural complications [Time frame: During the index procedure through 30 days]
• Disagreement in imaging findings between angiography and IVUS [Time frame: During the index procedure (Day 0)]
• Procedural success [Time frame: During the index procedure (Day 0)]

Eligibility criteria

Inclusion criteria

• Age ≥18 years.
• Documented chronic limb-threatening ischemia, meeting the following criteria according to guidelines(13):

• Presence of ischemic symptoms compatible with CLTI, defined as arterial insufficiency with gangrene, non-healing ischemic ulcer, or rest pain consistent with Rutherford classes 4-5 AND
• Imaging evidence within the past 12 months showing atherosclerotic PAD, including CTA, MRA, angiography or duplex ultrasound AND
• Ankle-Brachial Index (ABI) ≤0.80 or Toe-Brachial Index (TBI) ≤0.60 for patients who never underwent revascularization; ABI ≤0.85 or TBI ≤0.65 for those with history of prior revascularization procedures OR
• Ischemic rest pain alone (Rutherford class 4) with ankle systolic pressure <50 mmHg, toe pressure of <30 mmHg, transcutaneous PO2 of <30 mmHg, or flat-line transtarsal pulse volume recording OR
• Tissue loss with or without ischemic rest pain (Rutherford class 5) with ankle systolic pressure <70 mmHg, toe pressure of <50 mmHg, transcutaneous PO2 of <30 mmHg, or flatline transtarsal pulse volume recording
• Absence of occlusive upstream disease, defined by the following:

• Demonstrated vascular patency from the aorta to the second segment of the popliteal artery (P2), either by angiography, duplex ultrasound, CTA or MRA within the last 7 days prior to randomization
• In patients who underwent prior treatment for upstream disease, there are no restrictions in treatment modalities received as long as patency is demonstrated as previously defined
• If upstream disease is planned to be treated in the same index procedure, technically successful treatment of the upstream vessels must be achieved before randomization, defined as less than 30% residual stenosis and no flow-limiting dissections
• Informed Consent:

• Demonstrated ability and willingness to adhere to the study protocol and provide written informed consent

Exclusion criteria

• Age <18 years
• Asymptomatic or mild disease: patients who underwent revascularization for disease graded Rutherford classes 0-3
• Patients with major tissue loss (Rutherford 6) in whom major amputation was planned at the time of screening
• Patient with a history of prior major (above-the-ankle) amputation of the study limb
• Unable to tolerate any antiplatelet agent or with severe bleeding diathesis
• Clinical signs of active, uncontrolled, severe limb infection or septicemia, defined as fever exceeding 38.5°C, a white blood cell count above 15,000 cells/µL, or hypotension, at the time of screening (this does not include osteomyelitis confined to the phalanges or metatarsal heads or foot cellulitis treatable with IV antibiotics at the time of revascularization)
• Acute coronary syndrome or acute stroke within 30 days of screening
• Active hepatitis or severe liver cirrhosis (Child Pugh C)
• Advanced CKD (defined with eGFR<30 mL/min/1.73m2) or end-stage renal disease
• Pregnancy, breastfeeding, or women of childbearing potential who are not using an effective method of contraception
• Previous (within 30 days) or concomitant participation in another clinical study with investigational medicinal product(s) that has not yet reached its primary endpoint
• Life expectancy <1 year

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Double blind

Primary purpose

Treatment

Study locations

Taiwan · 4 centers

• Chi Mei Medical Center — Tainan
• National Taiwan University Hospital — Taipei
• Shin Kong Wu Ho-Su Memorial Hospital — Taipei
• Linkou Chang Gung Memorial Hospital — Taoyuan

Identifiers

NCT: NCT07731997 · 20251224R

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗