Optimal Strategy to Correct Stent underexpAnsion in Resistant Lesions (OSCAR)

Percutaneous coronary intervention (PCI) for in-stent restenosis (ISR) accounts for 5-10% of PCI. ISR may be linked to mechanical complications mainly under-expansion (UE), neointimal hyperplasia and/or neoatherosclerosis. International guidelines recommends non-compliant and very-high-pressure balloons, which lead to sub-optimal angiographic and clinical results. Recently, observational studies have suggested the feasibility and safety of intravascular lithotripsy (IVL) in UE treatment. There are no prospective randomised controlled studies comparing intravascular lithotripsy with balloons in ISR with UE.

Study Overview

• Status: Recruiting
• Conditions: Coronary Artery Disease; Restenosis; Coronary Angioplasty; Coronary Artery Disease (CAD); Angioplasty, Transluminal, Percutaneous Coronary; Coronary Stent Restenosis; Intravascular Lithotripsy; Rotational Atherectomy; OFDI; Optical Coherence Tomography (OCT); Percutaneous Coronary Intervention (PCI); Intravascular Lithotripsy; Restenosis of Coronary Artery Stent; Lithotripsy; OCT Angiography
• Intervention / Treatment: Procedure: Intravascular lithotripsy; Procedure: Balloon

Detailed Description

In-stent restenosis (ISR) angioplasties account for between 5 and 10% of Percutaneous coronary intervention (PCI). Several mechanisms are causing RIS, including neointimal hyperplasia, neoatherosclerosis, and/or mechanical complications, mainly stent under-expansion. In addition, the calcified lesions associated with stent under-expansion are under-diagnosed in angiography as shown by intra-coronary imaging studies. The stent under-expansion is defined as a ratio between the minimum intrastent surface area and the average vessel lumen of <80%. Currently, the management of these lesions is not codified and consists empirically of the use of non-compliant balloons, cutting balloons, and/or very high-pressure balloons. These treatments result in suboptimal angiographic results, with clinical consequences in terms of revascularization recurrence (angina, unstable angina, and in 25% of cases, acute coronary syndrome).

A growing interest in intravascular lithotripsy (IVL) use to treat these calcified lesions with stent underexpansion appears as an appealing option for a safe procedure but without robust data on efficacy. Furthermore, guidelines published in 2020 by the expert consensus of the EAPCI (European Association of Percutaneous Coronary Interventions) classified IVL among the therapeutic strategy indicated in stent under-expansion with calcified lesions. The OSCAR study is a randomized, controlled, multicenter trial investigating the use of IVL compared to other standard strategies in the treatment of in-stent restenosis with under-expansion.

• Study Type: Interventional
• Enrollment (Estimated): 80
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Lise Laclautre, Pharm.D; Phone Number: +33473754963; Email: promo_interne_drci@chu-clermontferrand.Fr

Study Locations

• France
  • Clermont-Ferrand, France, 63000
    • Not yet recruiting
    • CHU de Clermont-Ferrand
    • Principal Investigator: Géraud Souteyrand
    • Contact: LISE LACLAUTRE; Phone Number: +33473754963; Email: promo_interne_drci@chu-clermontferrand.fr
  • Auvergne
    • Clermont-Ferrand, Auvergne, France, 63000
      • Recruiting
      • Clermont Ferrand Hospital
      • Contact: Géraud SOUTEYRAND, Professor; Phone Number: 62308 +33 4 73 75 19 90; Email: gsouteyrand@chu-clermontferrand.fr

Participation Criteria

Eligibility Criteria

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

Description

Inclusion criteria :

• Patient who have undergone coronary angiography with ISR, defined as ≥50% reduction of the diameter of the intrastent lumen occurring ≥ 6 months after stent implantation
• And with a suspicion of stent under-expansion on angiography, possibly assisted by a stent enhancement technique
• The reference diameter of the target vessel must be ≥2.5 mm and ≤5.0 mm.
• Coronary flow must be TIMI 3
• Ability to cross the lesion with the OCT catheter (possibly after predilatation with a balloon up to 2 mm)
• Patient affiliated to the French National Health Insurance

Exclusion criteria :

• Heart failure with NYHA III or IV (or cardiogenic shock)
• LVEF <20%
• Chronic renal failure with clearance <30mL/mn according to CKD
• Pregnant or breast-feeding women
• Patient with a condition/comorbidity that could reduce compliance with the protocol, including pre-specified study follow-up
• Patient participating in another ongoing medical study evaluating a pharmacological or biological agent or medical device, unless authorized by the concomitant protocol.
• Patient unable to tolerate double antiaggregation (i.e., aspirin and clopidogrel or prasugrel or ticagrelor) for at least 6 months.
• Possible or defined thrombus (by angiography or endovascular imaging) in the target vessel.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Intravascular lithotripsy; ISR with UE will be treated by intravascular lithotripsy	Procedure: Intravascular lithotripsy; ISR with UE will be treated by intravascular lithotripsy
Active Comparator: Balloon; ISR with UE will be treated with non compliant balloons, very high-pressure balloons, cutting balloons	Procedure: Balloon; ISR with UE will be treated with non compliant balloons, very high-pressure balloons, cutting balloons

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Post PCI Stent expansion	Minimal stent area (MSA)/average reference vessel area	At enrollment

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Minimal stent area >4.5mm2 or Stent expansion ≥80%	Number of patients with Efficiency (yes/no) Efficiency defined by: optimal stent expansion (Minimal Stent Area [MSA]/mean reference vessel diameter ≥ 80%) and/or MSA > 4.5 mm².	At enrollment
Successful lithotripsy catheter delivery	Number of patients with successful lithotripsy catheter delivery	At enrollment
Procedural success evaluated by the occurence of the clinical events below	Procedural success is defined as residual stenosis < 50% or MSA > 4.5 mm2 and no angiographic complications (i.e., acute dissection (types B to F), perforation, acute vessel obstruction, persistent slow flow, or no reflow) or distal embolization.; Residual stenosis < 50% post-procedure (assessed by Quantitative Coronary Angiography (QCA)); No significant stent malapposition; Target lesion failure defined as: cardiac death, myocardial infarction (unless clearly attributable to a vessel other than the target vessel) and target lesion revascularization (TLR) during index hospitalization (Day 1-Day 7).; Target Vessel Failure (TVF) defined as: cardiac death, myocardial infarction (unless clearly attributable to a vessel other than the target vessel) and target vessel revascularization (TVR) during index hospitalization (Day 1-Day 7).	Day 1 - Day 7
Peri-procedural complications evaluated by the occurence of the clinical events below	Coronary arteries: Dissection (A-F), persistent slow flow, no reflow, perforation, embolization, acute vessel occlusion, side branch occlusion (>1.5 mm, final TIMI flow); Peri-procedural infarction; Vascular access complications: dissection, hematoma, pseudoaneurysm, hemorrhage; Radiation protection parameters: procedure time (min), air kerma, total dose-area product (DAP), iodine quantity (ml)	Day 1- Day 7
Safety criteria evaluated by the occurence of the clinical events below	All-cause mortality; Cardiovascular mortality; Peri-procedural myocardial infarction; Spontaneous myocardial infarction; Probable or definite stent thrombosis; Stroke; Major bleeding	From enrollment to the end of study at Month 36
Efficiency criteria evaluated by any of the clinical events described below	Target Lesion Revascularization (TLR); Target Vessel Revascularization (TVR); Target Vessel Non-Target lesion Revascularization (TV-NTLR); Non-Target Vessel Revascularization (NTVR); Any hospitalization (for cardiac reasons or related to the procedure)	From enrollment to the end of study at Month 36

Collaborators and Investigators

• Sponsor: University Hospital, Clermont-Ferrand
• Investigators: Principal Investigator: Géraud Souteyrand, MD, PhD, CHU de Clermont-Ferrand

Study record dates

Study Major Dates

• Study Start (Actual): October 22, 2025
• Primary Completion (Estimated): September 1, 2028
• Study Completion (Estimated): September 1, 2031

Study Registration Dates

• First Submitted: September 5, 2025
• First Submitted That Met QC Criteria: December 18, 2025
• First Posted (Actual): January 5, 2026

Study Record Updates

• Last Update Posted (Actual): January 5, 2026
• Last Update Submitted That Met QC Criteria: December 18, 2025
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Keywords: Percutaneous coronary intervention; randomized clinical trial; restenosis; intravascular lithotripsy; underexpansion; intrastent restenosis; baloon PCI
• Additional Relevant MeSH Terms: Vascular Diseases; Cardiovascular Diseases; Heart Diseases; Arteriosclerosis; Arterial Occlusive Diseases; Coronary Disease; Myocardial Ischemia; Coronary Artery Disease
• Other Study ID Numbers: RBHP 2025 SOUTEYRAND

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