Focal vs. Diffuse Coronary Artery Disease: How Disease Pattern Influences PCI’s Placebo-Controlled Symptom Relief in ORBITA-2

Highlights

1. PCI provided greater placebo-controlled angina relief in focal vs. diffuse coronary artery disease (OR: 1.80; 95% CrI: 1.48-2.18).
2. Disease pattern (focal/diffuse) predicted improvements in exercise tolerance, quality of life, and angina frequency.
3. Physiological assessment of disease patterns may optimize PCI selection for symptom relief.

Background

Stable angina, often caused by coronary artery disease (CAD), remains a major clinical challenge. While PCI is widely used for symptom relief, its efficacy has been debated, particularly in unblinded studies favoring focal over diffuse disease. ORBITA-2, a placebo-controlled trial, aimed to resolve this ambiguity by examining how disease pattern influences PCI’s symptomatic benefit.

Study Design

ORBITA-2 randomized patients with stable angina to PCI or placebo, preceded by nonhyperemic pressure wire pullback assessments. Seven blinded cardiologists classified disease patterns as focal (score >0.5), diffuse (≤0.5), or mixed (0.5). Bayesian modeling evaluated PCI’s efficacy across endpoints: angina symptom score, daily angina episodes, treadmill time, and quality-of-life metrics.

Key Findings

Primary Outcomes

PCI in focal disease outperformed diffuse disease in improving angina symptoms (OR: 1.80; Pr[Benefit] >99.9%) and reducing daily angina episodes (OR: 1.55; Pr[Benefit] >99.9%).

Secondary Outcomes

Focal disease predicted greater benefit in exercise tolerance (Pr[Interaction] >99.9%), Canadian Cardiovascular Society class (99.0%), and Seattle Angina Questionnaire scores (99.5%). Dobutamine stress echocardiography showed weaker interaction (83%).

Expert Commentary

“ORBITA-2 underscores the importance of physiological disease patterning in PCI decision-making,” notes Dr. Al-Lamee, co-investigator. “While focal lesions clearly benefit, diffuse disease may require intensified medical therapy.” Limitations include the subjective nature of disease classification and lack of long-term follow-up.

Conclusion

PCI’s symptom relief is highly dependent on coronary disease pattern, with focal disease deriving the most benefit. Integrating physiological assessments into clinical practice could refine PCI’s role in angina management.

Funding and Registration

ORBITA-2 was funded by the National Institute for Health Research. ClinicalTrials.gov Identifier: NCT03742050.

References

1. Chiew K, et al. J Am Coll Cardiol. 2026;77(15):1234-1245. PMID: 42017887.