What randomized trials have evaluated coronary revascularization (percutaneous coronary intervention) versus optimal medical therapy in patients with chronic stable angina, and what were their outcomes?

Coronary Intervention Trials in Chronic Stable Angina

For patients with chronic stable angina, PCI provides meaningful symptom relief but does not reduce mortality or myocardial infarction compared to optimal medical therapy alone, except in specific high-risk anatomic subgroups (left main disease, three-vessel disease, or proximal LAD involvement). 1

Key Trial Evidence

The ORBITA-2 trial (2023) provides the most rigorous placebo-controlled evidence: among 301 patients with stable angina who stopped antianginal medications, PCI resulted in significantly lower angina symptom scores (2.9 vs 5.6, P<0.001) compared to sham procedure at 12 weeks 2. This definitively proves PCI's symptomatic benefit beyond placebo effect.

However, the ISCHEMIA trial (referenced in guidelines) demonstrated no difference in major adverse cardiovascular events at 3.3 years between invasive and conservative strategies in 5,179 patients with moderate-severe ischemia 3. Only patients with daily, weekly, or monthly angina experienced prompt symptom improvement with revascularization.

The COURAGE trial showed that while PCI improved angina frequency, physical limitation, and quality of life scores by approximately 2 points, baseline patient characteristics (symptoms, age, diabetes, extent of disease) were actually more predictive of 1-year outcomes than the revascularization itself 4.

When Revascularization Improves Survival

The 2024 ESC Guidelines provide clear anatomic indications where revascularization (particularly CABG) improves mortality 1:

• Left main stenosis (LVEF >35%): Class I-A recommendation for revascularization to improve survival
• Three-vessel disease (LVEF >35%): Class I-A recommendation to improve long-term survival and reduce cardiovascular mortality and spontaneous MI
• Single or two-vessel disease involving proximal LAD (LVEF >35%): Class I-B recommendation to reduce cardiovascular mortality and spontaneous MI
• Multivessel disease with LVEF ≤35%: CABG recommended over medical therapy alone (Class I-B)

When PCI is Primarily for Symptoms

For patients without these high-risk anatomic features, PCI is recommended when persistent angina continues despite guideline-directed medical therapy, but the benefit is symptomatic rather than prognostic 1.

Recent meta-analyses confirm this: a 2025 systematic review of 14,171 patients found no difference in all-cause mortality, non-fatal MI, or stroke between revascularization and medical therapy, though 71.8% achieved freedom from angina with revascularization versus 62.9% with medical therapy alone (P<0.001) 5. The trade-off: increased procedural MI risk (RR 2.21) 5.

Critical Nuances

Patient selection matters enormously. The COURAGE trial analysis revealed that baseline symptom burden, age, diabetes, and extent of myocardium at risk were more important predictors of 1-year quality of life than whether PCI was performed (partial R² 0.29 vs 0.07 for angina frequency) 4.

Women are significantly underrepresented in these trials (only 2,401 women among 10,722 patients across four major trials). Available data show no mortality or MI benefit from revascularization in women, though some studies suggest better angina relief and reduced heart failure hospitalizations 6.

Practical Algorithm

1. Assess coronary anatomy first:

   • Left main, three-vessel disease, or proximal LAD involvement with LVEF >35% → Revascularization improves survival (prefer CABG for multivessel disease)
   • LVEF ≤35% with multivessel disease → CABG over medical therapy alone
   • Other anatomy → Revascularization is for symptoms only

2. For non-high-risk anatomy:

   • Optimize guideline-directed medical therapy first
   • If persistent angina despite optimal medications → Consider PCI for symptom relief
   • If asymptomatic or well-controlled on medications → Medical therapy alone is appropriate

3. Use objective ischemia assessment:

   • FFR, iFR, or QFR to guide lesion selection in multivessel disease (Class I-A) 1
   • IVUS or OCT for complex lesions (left main, bifurcations, long lesions) (Class I-A) 1

Common Pitfalls

Do not perform routine revascularization in asymptomatic patients on optimal medical therapy, even with positive stress tests—the ISCHEMIA trial showed no benefit 3. Silent ischemia without anginal symptoms was not associated with increased MACE risk in the CLARIFY registry 3.

Avoid routine follow-up angiography after PCI in asymptomatic patients—the ReACT trial showed this increases revascularization of non-ischemic lesions without improving cardiac death or MI rates 3.

The POST-PCI trial confirmed no benefit to routine functional stress testing at 12 months post-PCI in high-risk patients (no difference in death, MI, or unstable angina at 2 years) 3.