ORBITA Trial Implications — EECC MCQ

Correct answer: C — ORBITA showed that PCI for stable single-vessel CAD with significant stenosis did NOT improve exercise time compared with a sham procedure (placebo PCI) — suggesting that the symptomatic benefit of PCI in stable disease may partly reflect a placebo effect

The ORBITA trial (2018) was the first sham-controlled trial of PCI for stable angina. 200 patients with single-vessel CAD and ≥70% stenosis (with physiological confirmation) were randomised to PCI vs sham procedure (angiography with simulated PCI sounds but no intervention). Results: NO significant difference in exercise time (primary endpoint) at 6 weeks, though there were trends favouring PCI. Interpretation is debated: (1) placebo effect of PCI may account for much of the symptomatic improvement traditionally attributed to revascularisation in stable disease; (2) the trial was small, short duration (6 weeks), and enrolled patients with well-controlled symptoms on medical therapy. ORBITA-2 (2023) without background anti-anginal therapy showed PCI DID improve angina symptoms vs sham. The 2024 ESC CCS Guidelines position PCI for symptom relief (Class I) when medical therapy fails, not for routine prognostic benefit (ISCHEMIA trial).

Reference: ESC (2024): CCS Guidelines; ORBITA/ORBITA-2 Trials