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.
• Subject is at least 18 years old.
• Subject has acute cardiac pain/angina consistent with acute coronary syndrome eligible for coronary angiography meeting one of the following criteria:
‣ (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
⁃ Unstable angina
• Successful PCI (defined as diameter stenosis less than 30% and TIMI 3 flow on final angiography without procedural complication) of the culprit lesion.
• Subject has at least one high-risk plaque meeting the criteria below:
‣ Located in a non-culprit vessel,
⁃ High-risk plaque lesion on CCTA and at least one of the following features:
• Presence of low-attenuation plaque (HU\<50) and/or
∙ Positive remodelling (remodelling index \>1.1) and/or
∙ Napkin ring sign and/or
∙ Plaque burden ≥70%
⁃ Lesion length ≤ 20 mm.
⁃ 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).
⁃ Reference vessel diameter (RVD) \< 3.75 mm and \> 2.00 mm in diameter
⁃ Investigator considers that lesions are accessible.
⁃ If more than two suitable lesions available, investigator will select the most appropriate lesion for cryotherapy treatment.
• Subject is able to provide consent and has signed and dated the informed consent form.