Symptom relief remains the main reason for chronic total occlusion percutaneous coronary intervention (CTO PCI), but blinded randomized evidence has been limited. A multicenter randomized placebo-controlled trial published in the Journal of the American College of Cardiology found that CTO PCI improved angina beyond placebo in patients with symptomatic single-vessel CTO.

Patients had angina attributable to a single-vessel CTO without bystander coronary disease. Following dual-injection coronary angiography, participants were randomized to CTO PCI or a placebo procedure. Blinding was maintained using auditory isolation and deep conscious sedation. Antianginal medications were stopped at randomization and reintroduced using a patient-initiated protocol. Daily symptoms were recorded through the ORBITA app, with repeat assessment at 6 months.

Between October 2021 and October 2025, 50 patients were randomized, with 25 assigned to each group. One patient randomized to PCI was withdrawn during the procedure because of a complication, but all 50 patients were included in the primary analysis.

Compared with placebo, CTO PCI produced an immediate and sustained improvement in angina symptom score (odds ratio [OR] 4.38; 95% credible interval [CrI] 1.57-12.69; probability of benefit 0.996). Benefit was driven by fewer angina episodes (OR 4.38; 95% CrI 1.55-11.78; probability of benefit 0.997), resulting in 30.6 additional angina-free days (95% CrI 11.1-50.7; probability of benefit >0.999).

Improvements were also seen in Seattle Angina Questionnaire angina frequency, physical limitation, quality of life, summary score, and Canadian Cardiovascular Society class. Blinding of patients, staff, and researchers was maintained.

The findings indicate that CTO PCI improves angina beyond placebo in symptomatic single-vessel CTO.