This is a study to evaluate the safety and effectiveness of the Acolyte Catheter System used in CTO-PCI procedures. The system will be used for the placement and positioning of guidewires and catheters in the coronary vasculature for the treatment of patients with coronary chronic total occlusions with persistent symptoms following medical therapy.

This is a study to evaluate the safety and effectiveness of the Acolyte™ Catheter System used in CTO-PCI procedures as follows:

• Evaluate angiographic confirmation of guidewire placement beyond the CTO, in the true vessel lumen, in which the investigational device was utilized to facilitate crossing and/or re-entry.
• Evaluate in-hospital major adverse cardiac events (MACE).

Acolyte™ Optical Coherence Tomography (OCT) imaging will be utilized in all cases to inform guidewire advancement in the direction of true lumen. Additionally, Acolyte™ OCT imaging will be used to guide re-entry from the subintimal space to the true lumen.

Inclusion Criteria:

• Subject is > 18 years of age at the time of consent
• Subject is on medical therapy and continues to experience clinical symptoms considered suggestive of ischemic heart disease (e.g., chest pain or discomfort, heart failure) or has evidence of myocardial ischemia (e.g., abnormal functional study) attributed to the CTO target vessel and is scheduled for clinically indicated percutaneous revascularization
• Female subjects of reproductive potential must have a negative pregnancy test per standard of care for PCI
• Subject is willing and able to provided written informed consent
• Subject is willing to and able to comply with the study protocol requirements including all follow up visits post-procedure

Exclusion Criteria:

• Subject has history of allergy to iodinated contrast that cannot be managed medically
• Subject has evidence of acute myocardial infarction (MI) within 72 hours prior to the intended treatment
• Subject has had previous coronary interventional procedure of any kind within 30 days prior to the investigational procedure
• Atherectomy procedure is planned for the target lesion
• History of stroke or transient ischemic attack within 6 months prior to procedure
• Active peptic ulcer or upper gastrointestinal bleeding within 6 months prior to procedure
• History of bleeding diathesis or coagulopathy or refusal of blood transfusions
• Other pathology such as cancer, known mental illness, etc., or other condition which might, in the opinion of the Investigator, put the patient at risk or confound the results of the study
• Subject participating in an investigational drug or device study that has not completed the primary endpoint or that clinically interferes with this study's endpoints; or requires coronary angiography, intravascular ultrasound, or other coronary artery imaging procedures