Key Points
- CTO-PCI significantly improved angina symptom score compared with placebo in patients with symptomatic single vessel chronic toral occlusion driven by reduced angina frequency.
- Patients treated with CTO-PCI experienced approximately 30 additional angina-free days over 6 months.
Chronic total occlusion (CTO) percutaneous coronary intervention (PCI) is recommended for patients with refractory angina despite medical therapy; however, the true benefit of CTO-PCI has remained uncertain, with recent American guidelines downgrading the recommendation from Class IIa to Class IIb due to limited randomized evidence. Much of the existing data has been derived from observational studies and open-label trials, where placebo effects may contribute to perceived symptom improvement.
On March 29, 2026, at the American College of Cardiology Scientific Sessions, Dr. John Davies presented the primary results of ORBITA-CTO (NCT05142215), a randomized, double-blind, placebo-controlled trial evaluating the efficacy of CTO-PCI in patients with stable angina. The study was simultaneously published in the Journal of the American College of Cardiology.
ORBITA-CTO enrolled patients with single-vessel CTO, evidence of ischemia and myocardial viability, and symptomatic angina who were accepted for CTO-PCI by specialist operators, with lesion complexity limited to J-CTO ≤3. Following a period of medical optimization and baseline symptom assessment, patients were randomized to undergo either CTO-PCI or a placebo procedure consisting of a fully simulated intervention designed to maintain blinding. Patients, clinical staff, and investigators remained blind throughout the 24-week follow-up period. The primary endpoint was an angina symptom score derived from daily patient-reported angina frequency, anti-anginal medication use, and adverse clinical events. A total of 50 patients were randomized, with all participants included in the intention-to-treat analysis and no crossover between groups.
CTO-PCI resulted in a significant improvement in angina symptom score compared with placebo (odds ratio 4.38 [95% CI 1.57–12.69]; probability of benefit 99.6%). This corresponded to approximately 30.6 additional angina-free days over the 6-month follow-up period. The observed benefit was driven by a reduction in angina frequency, with no significant difference in anti-anginal medication use between groups. Secondary analyses demonstrated improvement in physician-assessed Canadian Cardiovascular Society (CCS) angina class in patients randomized to CTO-PCI compared with placebo. Blinding integrity was maintained throughout the study, supporting the validity of the placebo-controlled design and the observed treatment effect.
Taken together, these findings provide randomized, placebo-controlled evidence that CTO-PCI improves angina by reducing symptom frequency in carefully selected patients. Dr. Davies concluded that “ORBITA-CTO separates the true treatment effect from the placebo effect and shows that CTO-PCI improves angina beyond placebo, with a reduction in angina frequency that is immediate, sustained, and consistent across endpoints.”