Disclaimer: Haven't had a chance to read the original paper yet. IIRC, there was already pretty good evidence that angioplasty (without stenting) does not lower

Disclaimer: Haven't had a chance to read the original paper yet. IIRC, there was already pretty good evidence that angioplasty (without stenting) does not lower risk of death from heart disease unless there is actually an acute myocardial infarction (heart attack) in progress. In other words, if done in people having chest pain due to intermittently insufficient blood flow (angina), but not actually having a heart attack, there was no difference in death / disability, but there was less pain afterwards. Both angioplasty and stenting definitely help (reduced risk of death / disability) in people having acute heart attacks. There are also complications associated with stents. I certainly don't think it was unethical, but I agree with your question for this reason - many studies that may be ethical, but may lead to reduced sales of very expensive items somehow are deemed 'unethical'. I assume the way they did it was that everyone got a diagnostic angiogram, but only the experimental group got the stent. That way there was still benefit to all the patients (assuming diagnostic angiography is useful...), whether or not they got the stent.