ORbital Atherectomy for Lesion Preparation in Patients With Chronic Limb-threatening ischEmia (ORACLE)

ORACLE is a Europe-wide study that will follow 250 people with critical limb-threatening ischemia (CLTI). It aims to see how well orbital atherectomy (OA) works in real-life practice. OA is a procedure that uses a tiny spinning tool to gently remove hard calcium from inside an artery, helping to open the vessel so other treatments-like balloons or stents-can work better. The study focuses on people who have heavily calcified arteries in the femoropopliteal or infrapopliteal areas of the leg.

Study Overview

• Status: Not yet recruiting
• Conditions: Chronic Limb Threatening Ischemia; Chronic Limb-Threatening Ischemia
• Intervention / Treatment: Device: Stealth 360™ Peripheral Orbital Atherectomy System from Abbott

• Study Type: Observational
• Enrollment (Estimated): 250

Contacts and Locations

• Study Contact: Name: Claire Poulet, PhD; Phone Number: +41 79 385 16 78; Email: oracue@cirse.org
• Study Contact Backup: Name: Dhwani S. Korde, PhD; Phone Number: +4367762942469; Email: oracue@cirse.org

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Adult CLTI patients with femoropopliteal or infrapopliteal calcified lesions treated with OA using the Stealth 360 Peripheral OA System for vessel preparation prior to any adjunctive endovascular procedure.

Description

Inclusion Criteria:

1. Rutherford classification category ≥4;
2. Treatment of femoropopliteal or infrapopliteal calcified lesions with OA using the Stealth 360 peripheral OA System;
3. Calcification of target lesions must be visible on fluoroscopy or CT-angiography;
4. Patients competent and willing to provide informed consent.

Exclusion Criteria:

1. Minors and other vulnerable populations who may not be able to give informed consent freely or for whom participation is not essential to the study (incapacitated and unconscious individuals, persons deprived of liberty, pregnant and breastfeeding women, etc.);
2. Inadequate inflow (>30% stenosis) following optimization;
3. Insufficient direct outflow (less than 1 run-off vessel);
4. Endovascular procedure(s) on the treatment site within 4 weeks before index procedure;
5. Patients planned to receive an above ankle amputation of the target limb;
6. Patients enrolled in RESCUE (ClinicalTrials.gov ID NCT07270575).

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Adult CLTI patients with femoropopliteal or infrapopliteal calcified lesions; Eligible patients are those who will undergo OA prior to any adjunctive endovascular procedure	Device: Stealth 360™ Peripheral Orbital Atherectomy System from Abbott; The Stealth 360™ Peripheral Orbital Atherectomy System uses a diamond-coated, eccentrically mounted crown with bi-directional capabilities that treat a wide range of vessels, enabling single device treatment of multiple lesions and vessel sizes.; Other Names: Orbital Atherectomy; Orbital Atherectomy System

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of lesions with ≤30% residual stenosis after completion of full planned procedure	Defined as residual stenosis ≤30%, immediately after completion of full planned procedure (OA + any planned adjunctive intervention(s)).	Immediately after procedure completion

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of lesions with ≤30% residual stenosis after any unplanned endovascular intervention(s)	Defined as residual stenosis ≤30% immediately after completion of additional unplanned endovascular intervention(s) (any endovascular procedure that was not part of the primary procedure plan).	Immediately after procedure completion
Need for unplanned bailout stenting	Defined as any stent placement that was not part of the primary procedure plan.	Immediately after procedure completion
Number of participants free from Clinically-Driven Target Lesion Revascularization (CD-TLR)	Defined as freedom from any endovascular re-intervention to the target lesion (± 10 mm) or surgical bypass performed because of restenosis or occlusion of the target lesion.	12 and 24 months
CD-TLR-free survival	Defined as time between first OA procedure and any endovascular re-intervention to the target lesion (± 10 mm) or surgical bypass performed because of restenosis or occlusion of the target lesion.	Until the end of the follow-up period of 2 years
Overall survival	Defined as the time between the first OA procedure and death of any cause.	Until the end of the follow-up period of 2 years
Patient-reported health-related quality-of-life	Measured by Vascular Quality of Life Questionnaire - 6 items (VascuQol-6), which is a short patient-reported outcome measure (PROM), used to assess health-related quality of life in people with PAD. It consists of 6 questions, each scored from 1 to 7, with 1 as the worst possible quality of life and 7 as the best possible quality of life. Higher overall scores reflect better quality of life for patients with PAD.	Baseline, 6, 12 and 24 months post treatment
Clinical response using Rutherford classification categories	The Rutherford classification is a clinical scale used to categorize the severity of peripheral arterial disease: Category 0 = asymptomatic; Category 1 = mild claudication; Category 2 = moderate claudication; Category 3 = severe claudication; Category 4 = ischemic rest pain; Category 5 = minor tissue loss; Category 6 = severe tissue loss.	12 and 24 months
Wound status	Defined as healing status of the dominant ischemic wound of the target limb (complete, partial, unchanged, worsening).	12 and 24 months
Freedom from amputation of the target limb	Defined as absence of any amputation of the target limb (above ankle).	12 and 24 months
Amputation-free survival	Defined as time between first OA procedure and above-ankle amputation of the target limb.	Until the end of the follow-up period of 2 years
Frequency and severity of procedural complications and other adverse events	Grading according to the classification system of the Cardiovascular and Interventional Radiological Society of Europe.	Within 30 days after the OA procedure
Clinical response using ankle-brachial index (ABI)	The ankle-brachial index (ABI) is a non-invasive measure calculated as the ratio of systolic blood pressure at the ankle to systolic blood pressure at the arm. ABI categories commonly used to classify peripheral arterial disease are: >1.40 = non-compressible arteries; 1.00-1.40 = normal; 0.91-0.99 = borderline; 0.41-0.90 = mild to moderate peripheral arterial disease; <0.40 = severe peripheral arterial disease.	12 and 24 months
Clinical response using toe pressure	The toe pressure test measures distal limb perfusion by recording systolic pressure at the toe. In CLTI patients, toe pressure ≤30 mmHg is commonly used to indicate severe ischemia, while values >30 mmHg suggest better perfusion.	12 and 24 months
Clinical response using WIfi (wound, ischemia and foot infection) score	The WIfI classification is a staging system used to assess CLTI based on wound extent, ischemia severity, and foot infection. Each component is graded from 0 (none) to 3 (severe). Lower WIfI scores indicate a lower risk of limb loss and a lesser urgency for revascularization, whereas higher scores indicate greater disease severity, higher amputation risk, and greater potential benefit from revascularization.	12 and 24 months

Collaborators and Investigators

• Sponsor: Cardiovascular and Interventional Radiological Society of Europe
• Collaborators: Abbott
• Investigators: Study Chair: Gerd Grözinger, Prof. Dr. med., SLK Kliniken Heilbronn GmbH; Study Chair: Marianne Brodmann, Univ.-Prof. Dr. med., Medizinische Universitat Graz; Study Chair: Stefan Müller-Hülsbeck, Prof. Dr. med., DIAKO Krankenhaus gGmBH; Study Chair: Raghu Lakshminarayan, Dr, Hull University Teaching Hospitals NHS Trust

Publications and helpful links

General Publications

• Nordanstig J, Wann-Hansson C, Karlsson J, Lundstrom M, Pettersson M, Morgan MB. Vascular Quality of Life Questionnaire-6 facilitates health-related quality of life assessment in peripheral arterial disease. J Vasc Surg. 2014 Mar;59(3):700-7. doi: 10.1016/j.jvs.2013.08.099. Epub 2013 Dec 15.
• Filippiadis DK, Binkert C, Pellerin O, Hoffmann RT, Krajina A, Pereira PL. Cirse Quality Assurance Document and Standards for Classification of Complications: The Cirse Classification System. Cardiovasc Intervent Radiol. 2017 Aug;40(8):1141-1146. doi: 10.1007/s00270-017-1703-4. Epub 2017 Jun 5.

Study record dates

Study Major Dates

• Study Start (Estimated): April 1, 2026
• Primary Completion (Estimated): April 1, 2031
• Study Completion (Estimated): December 1, 2031

Study Registration Dates

• First Submitted: November 19, 2025
• First Submitted That Met QC Criteria: November 26, 2025
• First Posted (Estimated): December 8, 2025

Study Record Updates

• Last Update Posted (Estimated): January 2, 2026
• Last Update Submitted That Met QC Criteria: December 29, 2025
• Last Verified: November 1, 2025

More Information

Terms related to this study

• Keywords: Peripheral artery disease; OA; CLTI; Chronic limb ischemia; Infrapopliteal arteries; Observational cohort study; Orbital atherectomy; Vessel preparation; Calcified peripheral artery lesions; Critical limb-threatening ischemia; Femoropopliteal arteries; Atherectomy for calcified lesions
• Additional Relevant MeSH Terms: Vascular Diseases; Cardiovascular Diseases; Pathologic Processes; Chronic Disease; Disease Attributes; Atherosclerosis; Arteriosclerosis; Arterial Occlusive Diseases; Peripheral Vascular Diseases; Ischemia; Pathological Conditions, Signs and Symptoms; Chronic Limb-Threatening Ischemia; Peripheral Arterial Disease
• Other Study ID Numbers: ORACLE

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No