Researchers at Imperial College London tested that belief directly. Patients with a single narrowed artery and stable angina were randomly assigned to receive either a real stent or a sham procedure, where the catheter went in but nothing was opened.
Neither patients nor doctors scoring their symptoms knew which group they were in. Six weeks later, exercise time on a treadmill improved in both groups, with no significant difference, and the stent group's angina frequency scores were not significantly better than the sham group's.
The stent still opened the artery and improved blood flow on imaging, so the trial was not an argument against stents in general. It was a warning that a procedure can feel effective because of the ritual of receiving it. A 2023 follow-up in patients off anti-angina drugs did find greater relief with the stent, proven by testing, not assumed.
Read the original study
Al-Lamee et al., The Lancet, 2018 · doi.org/10.1016/s0140-6736(17)32714-9
A sham procedure made the stent prove itself.
Source
- Al-Lamee, R., Thompson, D., Dehbi, H.-M., Sen, S., Tang, K., Davies, J., Keeble, T., Mielewczik, M., Kaprielian, R., Malik, I. S., Nijjer, S. S., Petraco, R., Cook, C., Ahmad, Y., Howard, J., Baker, C., Sharp, A., Gerber, R., Talwar, S., . . . Swallow, R. (2018). Percutaneous coronary intervention in stable angina (ORBITA): a double-blind, randomised controlled trial. The Lancet, 391(10115), 31–40. https://doi.org/10.1016/s0140-6736(17)32714-9