Intravascular Ultrasound for Peripheral Artery Disease Revascularization

Official title

Intravascular Ultrasound for Peripheral Artery Disease Revascularization: The CLARITY Randomized Controlled Trial

Overview

The purpose of this study is to determine if IVUS use, as compared to angiography alone, prevent major adverse limb events (MALE) or binary restenosis (a greater than 50% re-narrowing of the treated artery) in adult patients who have CLTI and are undergoing percutaneous revascularization.

Interventions

• Procedure IVUS-guided strategy
  Percutaneous revascularization will be performed using intravascular ultrasound. The operators will follow instructions to modify arteries hardened by calcium and use IVUS to optimize the equipment (balloon and stents) used to unblock the artery.

Primary outcome measures

• Time-to-first occurrence of MALE [Time frame: From date of randomization until the date of first unplanned above ankle amputation of the index limb, clinically driven target lesion revascularization or target-lesion binary restenosis, assessed up to a maximum of 5 years.]

Secondary outcome measures (10)

• The composite of all-cause mortality, MALE, or target-lesion binary restenosis [Time frame: From date of randomization until the date of death, MALE, or target lesion binary restenosis, assessed up to a maximum of 5 years.]
• MALE [Time frame: From date of randomization, assessed up to a maximum of 5 years.]
• All-cause mortality [Time frame: From date of randomization, assessed up to a maximum of 5 years.]
• Unplanned above-ankle amputation of the index limb [Time frame: From date of randomization, assessed up to a maximum of 5 years.]
• Clinically-driven target lesion revascularization [Time frame: From date of randomization, assessed up to a maximum of 5 years.]
• Target lesion binary restenosis [Time frame: From date of randomization, assessed up to a maximum of 5 years.]
• Unplanned minor amputation of the index limb [Time frame: From date of randomization, assessed up to a maximum of 5 years.]
• Wound healing status of the index limb based on the Wound, Ischemia, Foot Infection (WIFI) scale throughout follow-up [Time frame: From date of randomization, assessed up to a maximum of 5 years.]
• Change in the Walking Impairment Questionnaire (WIQ) score throughout follow-up [Time frame: From date of randomization, assessed up to a maximum of 5 years.]
• Change in the Vascular Quality of Life Questionnaire-6 (VascQol-6) score throughout follow-up [Time frame: From date of randomization, assessed up to a maximum of 5 years.]

Eligibility criteria

Inclusion criteria

• Patients presenting with lower extremity PAD manifesting as CLTI:

a. CLTI is defined as ischemic rest foot pain, nonhealing wounds, or gangrene present for at least two weeks and that is attributable to objectively proven arterial occlusive disease, compatible with Rutherford class 4, 5 or 6, with the following supporting hemodynamic criteria1: i. For ischemic rest pain (Rutherford category 4): Ankle systolic pressure < 40mmHg, toe pressure < 30mmHg, or flat-line transtarsal pulse volume recording, OR ii. For tissue loss (Rutherford category 5, 6): Ankle systolic pressure < 60 mmHg, toe pressure of < 40mmHg, or flat-line transtarsal volume recording, AND

• Scheduled to undergo percutaneous revascularization, AND
• Informed consent
• Imaging evidence of an obstructive or occluded lesion (> 70%) in the infraiguinal circulation (e.g. femoral, popliteal, or infrapopliteal circulation) using angiography, ultrasound, computed tomography, or magnetic resonance imaging.
• An infrapopliteal lesion must be located in the proximal 2/3 of native infrapopliteal vessels, with a vessel diameter of > 2.5mm by investigator visual assessment.
• The distal margin of the most distal target lesion must be located > 10 cm proximal to the proximal margin on the ankle mortise. The vessel segment distal to the most distal target lesion must be patent all the way to the ankle, with no obstructive lesion (>50% stenosis).

Exclusion criteria

• The presence of anatomic or comorbid conditions or other medical, social, or psychological conditions that, in the investigator's opinion, could limit the potential participant's ability to participate in the trial or to comply with the follow-up requirements.
• The presence of any medical conditions precluding percutaneous revascularization
• The subject has previously had or requires surgical revascularization involving the vessel containing the target lesion of the ipsilateral extremity.
• The subject is bedridden or unable to walk (with assistance is acceptable).
• Life expectancy < 12 months
• Age < 18 years
• Active vasculitis, Buerger's disease, or acute limb-threatening ischemia
• Planned above-ankle amputation of the index limb within four weeks of the index procedure.
• Obstructive supra-inguinal "inflow" (>70% stenosis) which is not planned to be treated during index procedure or within 30 days of the index procedure.
• The subject has had any amputation to the ipsilateral extremity other than the toe or forefoot, or the subject has had a major amputation to the contralateral extremity < 1 year before the index procedure and is not independently walking.
• Extensive tissue loss that is salvageable only with complex foot reconstruction or non-traditional trans metatarsal amputations.

• Osteomyelitis that extends proximal to the metatarsal heads
• Gangrene involving the plantar skin of the forefoot, midfoot or heel
• Deep ulcer or large shallow ulcer (> 3 cm) involving the plantar skin of the f forefoot, midfoot, or heel
• Full-thickness heel ulcer
• Any wound with calcaneal bone involvement
• Wounds that would require flap coverage or complex wound management for large soft tissue defect
• Full-thickness wounds on the dorsum of the foot with exposed tendon or bone.

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

Single blind

Primary purpose

Prevention

Study locations

Canada · 2 centers

• Hamilton General Hospital — Hamilton
• Unity Health Toronto - St. Micheal's Hospital — Toronto

Identifiers

NCT: NCT06979284 · 5251

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗