Intracoronary Cryotherapy Effect on Stabilization of Vulnerable Plaque in Patients With (N)STEMI or Unstable Angina (POLARSTAR)

March 20, 2026 updated by: Cryotherapeutics SA

Clinical Investigation of Intracoronary Cryotherapy Using the CryoTherapy System (CTS) for High-risk Plaque in Patients With (Non-)ST-segment Elevation Myocardial Infarction (NSTEMI) or Unstable Angina

The POLARSTAR study is an early safety and feasibility study to evaluate the performance and safety of the CryoTherapy System (CTS) for the treatment of coronary plaque lesions that are not obstructing blood flow but are at high-risk of rupture which would cause a major heart attack. The CTS is used to apply local freezing of the lesion using a balloon catheter, controlled by a console that regulates in- and outflow of a cooling agent into the catheter. The treatment is expected to stabilize the lesion, diminishing the risk of rupture. The study will enrol subjects with acute coronary disease who have suitable coronary lesions. Subjects will be followed for 1 year after the CTS treatment. Baseline identification of lesions will be done using Coronary CT-angiography (CCTA), which will be repeated at 3 and 9 months after procedure.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Active, not recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

The POLARSTAR study is an early feasibility study to evaluate the safety and performance of the CryoTherapy System (CTS) medical device, consisting of a console and a balloon catheter. The CTS is designed to deliver local cryo-energy to vulnerable plaque lesions in the coronary arteries, aiming to stabilize the plaque to reduce the risk of rupture and subsequent cardiac events. The study will enrol up to 10 subjects with NSTEMI or unstable angina, who underwent successful Percutaneous Coronary Intervention (PCI) of their culprit coronary lesion, and who were identified to have presence of at least 1 non-culprit suitable plaque lesion at high-risk of rupture. After providing informed consent the subjects will undergo a Coronary CT-angiography (CCTA) to confirm suitability of the coronary plaque lesion. A single high-risk plaque lesion will be treated by the investigators, with Intra-vascular Ultrasound (IVUS) imaging prior to and after CTS treatment. Subjects will be followed clinically for up to one year after the CTS treatment, and will have follow-up CCTA assessments at 3 and 9 months post-procedure. Primary endpoint will be Major cardiac events rate at 3 months post procedure.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
30

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • Georgia
      • Tbilisi, Georgia, 0186
        • Tbilisi Heart Center
      • Tbilisi, Georgia, 0112
        • Israeli-Georgian Research Clinic Helsicore
  • Lithuania
      • Kaunas, Lithuania, LT-50161
        • Hospital of Lithuanian University of Health Sciences Kauno klinikos
      • Klaipèda, Lithuania, LT-92288
        • Klaipeda university hospital
      • Vilnius, Lithuania, LT-08661
        • Vilnius University Hospital Santaros Klinikos

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Subject is at least 18 years old.

  2. Subject has acute cardiac pain/angina consistent with acute coronary syndrome eligible for coronary angiography meeting one of the following criteria:

    1. (Non-)ST-segment elevation myocardial infarction ((N)STEMI) with rise/fall of cardiac enzymes (troponin I or T) with at least one value above the 99th percentile of the upper reference limit requiring PCI within 72 hours from diagnosis
    2. Unstable angina
  3. Successful PCI (defined as diameter stenosis less than 30% and TIMI 3 flow on final angiography without procedural complication) of the culprit lesion.

  4. Subject has at least one high-risk plaque meeting the criteria below:

    1. Located in a non-culprit vessel,

    2. High-risk plaque lesion on CCTA and at least one of the following features:

      1. Presence of low-attenuation plaque (HU<50) and/or
      2. Positive remodelling (remodelling index >1.1) and/or
      3. Napkin ring sign and/or
      4. Plaque burden ≥70%
    3. Lesion length ≤ 20 mm.
    4. Diameter stenosis on invasive angiography between 30% and 70% on coronary angiogram or negative physiology assessment (FFR>0.80 or non-hyperemic pressure ratios (NHPR) >0.89).
    5. Reference vessel diameter (RVD) < 3.75 mm and > 2.00 mm in diameter
    6. Investigator considers that lesions are accessible.
    7. If more than two suitable lesions available, investigator will select the most appropriate lesion for cryotherapy treatment.
  5. Subject is able to provide consent and has signed and dated the informed consent form.

Exclusion Criteria:

  1. Subject is hemodynamically unstable (cardiogenic shock, hypotension needing inotropes, hypoxia needing intubation, refractory ventricular arrhythmias, and IABP).
  2. Subject has ongoing ST-segment elevation myocardial infarction.
  3. Subject had a procedural complication during the Acute coronary syndrome (ACS) PCI procedure.
  4. Subject has history of Coronary Artery Bypass Graft (CABG) or planned CABG within 12 months after the index procedure.
  5. Subject has known reduced Left Ventricular Ejection Fraction < 30%.
  6. Subject has known severe valvular heart disease.
  7. Subject has known severe renal insufficiency (eGFR <30 ml/min/1.72 m2).
  8. Subject has any life-threatening conditions or medical comorbidity resulting in life expectancy < 12 months.
  9. Subject is currently participating in another clinical investigation that has not yet reached its primary endpoint.
  10. Subject is pregnant or lactating, or NOT surgically sterile (tubal ligation or hysterectomy) or NOT postmenopausal for at least 6 months or is a female with childbearing potential without effective contraception (pill, patch, ring, diaphragm, implant and intrauterine device).

Angiographic exclusion criteria:

  1. Visible distal embolization/no-reflow following culprit lesions PCI.
  2. Left main coronary artery disease (visual diameter stenosis > 50%).
  3. Stent thrombosis/restenosis as a culprit lesion.
  4. CTS lesion involving a bifurcation (defined as lesions involving side branches >2.0 mm).
  5. Angiographic or CCTA evidence of severe calcification and/or marked tortuosity of the index vessel and/or lesion.
  6. Thrombotic lesions
  7. Ostial lesions

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Device Feasibility
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: CTS Treatment Arm
active cryotherapy of a single suitable high-risk coronary plaque lesion with CTS device
Device: CryoTherapy System (CTS)
local cryotherapy of coronary high-risk plaque lesions using the CTS consisting of a semi-compliant balloon and a console controlling the temperature of cryotherapy

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Safety: Rate of Cryotherapy related adverse events
Time Frame: 90 days post-procedure
Any cryotherapy procedure related complication defined as coronary artery dissection (angiographic dissection ≥ NHLBI type B), acute vessel closure, life threatening arrythmia, need for bailout stenting, or any Major Adverse Cardia Event (MACE) defined as cardiac death, CTS-treated vessel myocardial infarction, CTS-treated lesion revascularization, rehospitalization for unstable or progressive angina adjudicated to the CTS-treated lesion
90 days post-procedure

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Safety: Rate of Cryotherapy related events
Time Frame: 1 year post-procedure
Any cryotherapy procedure related complication defined as coronary artery dissection (angiographic dissection ≥ NHLBI type B), acute vessel closure, life threatening arrythmia, need for bailout stenting, or any MACE defined as cardiac death, CTS-treated vessel myocardial infarction, CTS-treated lesion revascularization, rehospitalization for unstable or progressive angina adjudicated to the CTS-treated lesion
1 year post-procedure
Device success
Time Frame: end of CTS treatment
Number of lesions successfully treated without device deficiency
end of CTS treatment
CTS procedure success
Time Frame: end of CTS treatment
Number of lesions successfully treated to obtain Thrombolysis in Myocardial Infarction (TIMI) 3 flow
end of CTS treatment
Imaging: CCTA assessed Minimum lumen area (MLA)
Time Frame: 90 days post-procedure
Change in MLA (mm²) compared to baseline
90 days post-procedure
Imaging: CCTA assessed Minimum lumen area (MLA)
Time Frame: 9 months post-procedure
Change in MLA (mm²) compared to baseline
9 months post-procedure
Imaging: CCTA assessed area stenosis
Time Frame: 3 months post-procedure
Change in area stenosis % compared to baseline
3 months post-procedure
Imaging: CCTA assessed area stenosis
Time Frame: 9 months post-procedure
Change in area stenosis % compared to baseline
9 months post-procedure
Imaging: CCTA assessed lesion plaque burden
Time Frame: 3 months post-procedure
Change in lesion plaque burden % from baseline
3 months post-procedure
Imaging: CCTA assessed lesion plaque burden
Time Frame: 9 months post-procedure
Change in lesion plaque burden from baseline
9 months post-procedure
Imaging: CCTA assessed Total plaque volume
Time Frame: 3 months post-procedure
Change in total plaque volume (mm³) from baseline
3 months post-procedure
Imaging: CCTA assessed Total plaque volume
Time Frame: 9 months post-procedure
Change in total plaque volume(mm³) from baseline
9 months post-procedure

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Cryotherapeutics SA

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
CoreAalst BV

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Irakli Gogorishvili, MD, Israeli_Georgian research Clinic Helsicore, Tbilisi, Georgia

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
May 18, 2022

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
June 30, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
July 31, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
October 26, 2022

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
October 26, 2022

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
October 31, 2022

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
March 24, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 20, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
March 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • CT-CD-P03-1

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

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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