Re-entering a chronically occluded coronary artery after an unsuccessful attempt remains an important decision in CTO intervention. This randomized study evaluated whether early or late staged PCI after STAR improves procedural outcomes. The trial enrolled 150 adults across 6 centers who underwent CTO PCI using STAR as a bailout method and were randomized to staged stenting at 5–7 weeks or 12–14 weeks.

The primary endpoint was partial technical success, defined as achieving Thrombolysis in Myocardial Infarction (TIMI) grade 2–3 flow with <30% residual stenosis into at least one distal branch ≥2.5 mm. The early group included 73 adults and the late group included 77 adults. Partial technical success occurred in 83.6% of the early group and 71.4% of the late group, which did not reach statistical significance.

Vessel patency at the start of the staged procedure was higher with early staging. TIMI grade 2–3 flow was present in 64.4% of the early group compared with 44.2% of the late group. This pattern suggests that earlier re-entry may preserve antegrade flow and improve the procedural environment for stent placement.

Overall, both timing strategies produced high procedural success. Early staging may offer a technical advantage through better preserved flow, although success rates were not significantly different between the two groups.