The Role of the Collateral Circulation in Stable Angina: An Invasive Placebo-Controlled Study
Authors' conclusion
Coronary collateralization is associated with ischemic burden and may reduce the intensity of ischemic chest pain.
Study context
- Population
- Patients with severe single-vessel CAD and angina, antianginal medications stopped
- Participants
- 51 patients
- Comparison
- Balloon occlusion vs audiovisually identical placebo inflation, in randomized order
Methodological detailsplacebo-controlled, n-of-1, invasive
- Placebo-controlled
- n-of-1
- Invasive
Main finding
As reported in the abstract
Associations of ischaemia, collateral flow and angina (Somers' D, Bayesian Pr)
- Daily angina frequency vs FFR: little correlation
- Somers' D 0.124, Pr=0.057
- Daily angina frequency vs iFR: little correlation
- Somers' D 0.056, Pr=0.150
- Lower FFR and greater collateral flow: strong evidence of association
- Somers' D 0.302, Pr=0.998
- Lower iFR and greater collateral flow: strong evidence of association
- Somers' D 0.316, Pr=0.999
- Higher collateral flow index and lower pain intensity scores: strong evidence of association
- Somers' D 0.341, Pr=0.999
Original publication
The Role of the Collateral Circulation in Stable Angina: An Invasive Placebo-Controlled Study. Circulation. Published 27 October 2025. doi:10.
Summarised from the published abstract; every number is checked against it