Bold takeaway: In complex CTO cases, splitting the intervention into two procedures with STAR can yield strong technical results and may improve safety, challenging the idea that one long procedure is always best.
Two-stage CTO PCI with STAR shows promising outcomes for hard-to-cross lesions, regardless of whether the second procedure occurs within about 2 or 4 months. In a randomized trial of bailout CTO PCI, patients who underwent the staged approach after STAR achieved high technical success, with no clear difference between the early (5–7 weeks) and the later (12–14 weeks) second procedures in overall partial technical success (83.6% vs 71.4%; P = 0.08). Notably, the early group did better on the secondary endpoint of TIMI flow grade 2-3 in the target vessel at the staged procedure's start (64.4% vs 44.2%; P = 0.012).
These results bolster the shift toward a two-stage strategy to improve stent patency and outcomes in patients with highly complex CTOs, aligning with nonrandomized data like INVEST-CTO that suggested staged PCI can enhance safety.
Azzalini noted surprise at these findings because prior studies implied waiting longer (around 60 days) before the second stage would improve results. Based on the new data, he has adjusted practice to encourage earlier follow-up, arguing it streamlines the patient’s overall care journey and better fits their life plans.
The STAR method, developed by Antonio Colombo, MD, involves creating a deliberate subintimal dissection and subsequent re-entry into the true lumen, often near bifurcations, to access difficult lesions. While advantageous for crossing tough blocks, excessive long-stent use remains a concern. Reassessing timing and re-evaluating stent length may yield better long-term outcomes.
Colombo emphasized that earlier second-stage intervention showed a favorable trend in this study, even if statistical significance wasn’t reached. He suspects a larger trial might confirm the benefit and suggests early follow-up could be used to salvage suboptimal acute results.
STAR trial overview: Conducted at six U.S. centers, the trial randomized 150 patients (mean age ~66; 17% women) undergoing CTO PCI with STAR to early (n=73) or late (n=77) staged PCI between January 2022 and August 2024. All participants had STAR as a bailout after an unsuccessful initial CTO attempt, with a mean J-CTO score of 2.9. Lesions were most commonly in the right coronary artery, followed by the circumflex and left anterior descending arteries. Occlusion lengths averaged mid-30s millimeters. About two-thirds of lesions were calcified, with roughly a quarter representing reattempts.
Partial technical success—defined as TIMI grade 2-3 flow with less than 30% residual stenosis in at least one distal branch ≥2.5 mm—favored the early group but did not differ for complete technical success (67.1% vs 61.0%; P = 0.44).
MACCE rates were similar between groups (6.8% early vs 3.9% late; P = 0.49), driven mainly by perforations (eight during the initial procedure, two during staging). There were no in-hospital deaths or emergency surgeries in either group, with one stroke occurring after a staged procedure.
Most staged procedures used antegrade wiring (64.4%), with additional strategies including Stingray-based dissection and reentry (6.5%), retrograde approaches (20%), and a smaller share of repeated STAR (5.3%).
Multivariate analysis suggested a trend toward higher partial technical success with early staging (odds ratio 2.15; 95% CI 0.93–4.97).
Expert commentary and implications: Azzalini argues for broader accessibility of STAR, noting the barriers of perceived complexity and administrative support. He sees STAR as a step toward democratizing access to high-level CTO PCI outcomes, provided it is pursued after other CTO strategies have been explored.
Editorial perspective reinforces the idea that randomized strategy trials in CTO PCI are rare but valuable, especially when they challenge prior intuitions. The accompanying editors suggest that CTO PCI may benefit from two procedures to optimize safety and efficacy and caution against delaying staged interventions based on outdated consensus.
Future directions: Researchers call for a randomized comparison between upfront STAR with staged PCI and conventional single-procedure approaches, powered to assess both success and complication rates. They also stress studying the optimal timing for stenting during the index STAR procedure to possibly reduce the need for staged interventions. Additional research into the role of drug-coated balloons in the subintimal space—comparing sirolimus- vs paclitaxel-coated balloons—would provide further clarity.
What this means for practice:
- For complex CTOs, a two-stage plan with STAR may improve long-term patency and safety, even when the second stage occurs earlier than previously recommended.
- The decision to stage earlier should consider patient life plans, logistics, and the potential for quicker completion of care pathways.
- Wider adoption will require addressing technical barriers and ensuring appropriate institutional support, while continuing to refine patient selection and procedural sequencing.
Questions for discussion: Do you agree that two-stage CTO PCI should become the default approach in the most challenging lesions, or should patient-specific factors dictate the timing more aggressively? What are the barriers you see to implementing STAR more broadly in everyday practice, and how might they be overcome? Would you favor a trial comparing upfront STAR versus single-procedure strategies to settle the timing question once and for all?
