STAR is a minimal-risk pragmatic clinical trial of patients admitted for a CTO-PCI procedure. The overall objective of the STAR Study is to address the current gaps in knowledge regarding use of STAR during CTO-PCI, as a prospective, multi-center study of 150 participants with randomization of timing of staged PCI. Five sites will be selected to participate in STAR from a national network of highly experienced CTO-PCI centers across the United States.

To date, there have been no studies that prospectively and systemically evaluated the efficacy and safety of STAR with deferred stenting and described the frequency of its use in the hybrid approach. The aim of this study is to address these current gaps in knowledge, including the frequency of use of STAR by experienced operators, the safety of its use, optimal timing of staged stenting and health status change associated with this procedure. This prospective study will enroll 150 patients undergoing elective PCI of native CTO utilizing the STAR technique and will subsequently randomize patients in a 1:1 fashion to early (5-7 weeks) and later (12-14 weeks) timing of subsequent stenting.

Inclusion Criteria:

1. Subject is scheduled for a PCI procedure for at least one chronic total occlusion with TIMI antegrade flow of zero.
2. Subject is ≥ 18 years of age at the time of consent
3. The operator attempted STAR technique defined as knuckle guidewire across or into the CTO segment during the CTO PCI and is planned for a staged procedure.
4. English speaking due to follow up.

Exclusion Criteria:

1. The CTO segment is in a graft.

2. Female subjects with a positive quantitative or qualitative pregnancy test, in accordance with hospital policy.

3. Unable to participate in telephone follow-up

   1. Too hard of hearing to do follow-up by telephone or deaf.
   2. Incarcerated prisoner.
   3. History of dementia.
   4. Subjects without a way for contact by telephone for follow-up.

4. Previously enrolled in STAR.

5. Patient not a candidate for baseline and final angiography (CKD with eGFR<30).

6. The knuckled guidewire did not cross into the CTO segment during STAR attempt.

7. A stent was placed into the STAR segment during the Index Procedure.

8. Refused participation in the study.

9. Patient enrolled in another study.