The fundamental question motivating the COURAGE trial was whether using PCI to reverse flow-limiting stenoses (narrowing of coronary arteries) would reduce the risk of MI and death among CAD patients more than OMT would. While PCI had been shown to provide substantial benefit for patients with ACS, its benefit for the stable CAD population had not been conclusively demonstrated. Previous studies had shown that PCI could decrease angina frequency and improve short-term exercise performance in that population, but it did not clearly reduce cardiovascular-event frequencies over either short or long time frames. However, most of the clinical trials that assessed these end points were small and underpowered (Boden, O’Rourke, et al., 2007), enrolling a total of only 1,872 patients (Diamond and Kaul, 2007). A meta-analysis of trials among patients with stable CAD published in 2005 showed that PCI achieved no reduction in acute coronary events or death compared with OMT (Katritsis and Ioannidis, 2005).
The superiority of PCI in improving quality-of-life outcomes for patients with stable CAD had also not been demonstrated conclusively. Few large-scale studies had addressed this question, and moreover, the treatments used in prior studies were already out of date, including neither the current treatment approaches for medical management nor the use of intracoronary stents for patients who received PCI.