What happened
In patients with single-vessel CTO, CTO PCI improved the angina symptom score compared with a placebo procedure (OR 4.38; 95% CrI 1.57-12.69; Pr[Benefit]=0.996).
Multiple experts agree that ORBITA-CTO fills a critical evidence gap by providing the first blinded, placebo-controlled demonstration that CTO PCI truly improves angina symptoms beyond placebo effect.
Experts read ORBITA-CTO as the first placebo-controlled proof that CTO PCI genuinely relieves angina, though they flag questions about how broadly the results apply beyond the trial's highly selected patients and operators.
Interventional cardiologists welcome this as landmark evidence that CTO PCI produces real, not placebo-driven, symptom relief. There is broad agreement the trial design was rigorous, but some experts caution that the tightly selected patient population and specialist operators may limit generalizability. The live question is which patients and clinical settings will see the same benefit.
Experts note that the trial enrolled a narrow group of patients with single-vessel CTOs treated by specialist operators, leaving open how well the results generalize to broader CTO populations and less experienced centers.
Determining which patients benefit most from the procedure remains the next challenge.
“The original ORBITA trial fundamentally changed how we interpret symptom outcomes after conventional non-CTO PCI. If we want to know whether CTO PCI truly works, we must also test it under blinded conditions.”
Conference Coverage ↗From published coverage, not an answer posted here.
Sergio Waxman
Endpoint critiqueInterventional cardiologist, RWJ Barnabas HealthGeneralizability is the main concern given the highly selected patients and operators
Original post ↗Ziad A. Ali
ContextInterventional cardiologist, institution not specifiedThis evidence is invaluable for a field that relied on technical success as a surrogate for clinical effect
Original post ↗John Davies
Results readoutInterventional cardiologist, Essex Cardiothoracic CentreCTO PCI delivers immediate, sustained, and consistent angina relief even against placebo
Original post ↗J. Dawn Abbott
ContextInterventional cardiologist, Brown University HealthThe true placebo-adjusted benefit of CTO PCI was unanswered until this trial
Original post ↗Upvote a question you would like answered, or open it to join the discussion.
Why the trial, key points, tables, limitations, PICO, abstract, media & sources
Why the trial?
The ORBITA-CTO trial was conducted to address the lack of blinded randomized evidence on whether percutaneous coronary intervention (PCI) for coronary chronic total occlusion (CTO) improves symptoms and quality of life in patients with angina attributable to a single-vessel CTO.
Does CTO PCI improve angina symptoms in patients with stable angina attributable to a single-vessel CTO compared to a placebo procedure?
RCT (n=50)
Blinded
Randomized
Yes
Does CTO PCI improve angina symptoms in patients with stable angina attributable to a single-vessel CTO compared to a placebo procedure?
In the first placebo-controlled trial of CTO PCI, the procedure significantly improved angina symptoms and quality of life in patients with single-vessel CTO.
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Expert reaction
JACC · ACC Annual Scientific Session 2025
What 3 experts said about this trial's result
Expert labels are toward ORBITA-CTO's result, from named public quotes (n=3). As of Sep 17, 2026.
Experts read ORBITA-CTO as the first placebo-controlled proof that CTO PCI genuinely relieves angina, though they flag questions about how broadly the results apply beyond the trial's highly selected patients and operators.
Interventional cardiologists welcome this as landmark evidence that CTO PCI produces real, not placebo-driven, symptom relief. There is broad agreement the trial design was rigorous, but some experts caution that the tightly selected patient population and specialist operators may limit generalizability. The live question is which patients and clinical settings will see the same benefit.
Multiple experts agree that ORBITA-CTO fills a critical evidence gap by providing the first blinded, placebo-controlled demonstration that CTO PCI truly improves angina symptoms beyond placebo effect.
Experts note that the trial enrolled a narrow group of patients with single-vessel CTOs treated by specialist operators, leaving open how well the results generalize to broader CTO populations and less experienced centers. Determining which patients benefit most from the procedure remains the next challenge.
“The original ORBITA trial fundamentally changed how we interpret symptom outcomes after conventional non-CTO PCI. If we want to know whether CTO PCI truly works, we must also test it under blinded conditions.”
Waxman praised the trial design as meticulous but cautioned that enrolling only patients with single-vessel CTOs and no other significant coronary disease, treated by a selected group of operators, raises questions about how broadly the results can be applied.
Ali called the trial invaluable for moving CTO PCI beyond technical accomplishment toward proven clinical benefit. He identified the next challenge as determining when and for whom the procedure works best.
Supports CTO PCI for symptom relief in single-vessel CTO; confirms benefit in first placebo-controlled RCT and strengthens Class IIa guidance.
BACKGROUND: Percutaneous coronary intervention for coronary chronic total occlusion (CTO PCI) is offered for symptom and quality of life improvement, despite the absence of blinded randomized evidence. OBJECTIVES: The aim of this study was to assess the efficacy of CTO PCI in the first randomized, placebo-controlled trial of CTO PCI. METHODS: ORBITA-CTO is a multicenter, randomized, blinded trial comparing CTO PCI with a placebo procedure. Patients had angina attributable to a single-vessel CTO, without bystander coronary disease. Angina symptoms were recorded daily using the ORBITA app. After dual-injection coronary angiography, patients were randomized to either CTO PCI or placebo. Blinding was maintained using auditory isolation and deep conscious sedation. Antianginal medications were stopped at randomization and reintroduced on a patient-initiated protocol. At the 6-month follow-up, assessments were repeated. The primary efficacy outcome was the angina symptom score, an ordinal scale combining the daily symptom burden assessed by the ORBITA app, antianginal use, and over-ride events. Secondary outcomes were symptom and quality of life questionnaires and blinding fidelity. RESULTS: Between October 19, 2021 and October 21, 2025, 50 patients were randomly assigned to CTO PCI (n = 25) or placebo (n = 25). One patient randomized to PCI was withdrawn during the procedure because of a complication. All 50 patients were included in the primary analysis. Compared with placebo, CTO PCI resulted in an immediate and sustained improvement in the angina symptom score (OR: 4.38; 95% credible interval [CrI]: 1.57-12.69; probability of benefit [Pr{Benefit}] = 0.996), arising from a clear reduction in the number of episodes of angina (OR: 4.38; 95% CrI: 1.55-11.78; Pr[Benefit] = 0.997). This resulted in an additional 30.6 days free of angina (95% CrI: 11.1-50.7; Pr[Benefit] >0.999). Improvements were also observed with the Seattle Angina Questionnaire in angina frequency (+10.7; 95% CrI: 1.4-20.2; Pr[Benefit] = 0.988), physical limitation, quality of life, and summary score and Canadian Cardiovascular Society class. Blinding of patients, staff, and researchers was maintained. CONCLUSIONS: In patients with symptomatic single-vessel CTO, CTO PCI improves angina beyond placebo. (A Placebo-controlled Trial of Chronic Total Occlusion Percutaneous Coronary Intervention for the Relief of Stable Angina [ORBITA-CTO]; NCT05142215).
Khan et al. (2026) conducted an RCT in Stable angina with single-vessel chronic total occlusion (n=50). Chronic Total Occlusion Percutaneous Coronary Intervention (CTO PCI) vs. Placebo procedure was evaluated on Angina symptom score (ordinal scale combining daily symptom burden, antianginal use, and over-ride events) (OR 4.38, 95% CI 1.57-12.69, p=Pr[Benefit] = 0.996). In patients with single-vessel CTO, CTO PCI improved the angina symptom score compared with a placebo procedure (OR 4.38; 95% CrI 1.57-12.69; Pr[Benefit]=0.996).
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