Coronary Microvascular Resistance as a Predictor of the Placebo-Controlled Response to Percutaneous Coronary Intervention: Microvascular-Stratified Analysis of ORBITA

Scritto il 27/04/2026

da Daniel J Taylor

CONCLUSIONS: The placebo-controlled benefit of PCI was greater in patients with lower MVR(CFD), but interactions with symptom-based endpoints were modest. For patients with severe single-vessel disease taking optimal medical therapy, microvascular dysfunction may attenuate the functional and symptomatic benefits of PCI.

JACC Cardiovasc Interv. 2026 Mar 31:S1936-8798(26)00773-9. doi: 10.1016/j.jcin.2026.01.305. Online ahead of print.

ABSTRACT

BACKGROUND: The first placebo-controlled trial of percutaneous coronary intervention (PCI), ORBITA (Objective Randomised Blinded Investigation With Optimal Medical Therapy of Angioplasty in Stable Angina; NCT02062593), showed minimal symptom benefit with PCI. No placebo-controlled data describing the relationship between microvascular resistance (MVR) and PCI exist. The authors hypothesized that patients with low MVR would derive the greatest benefit from PCI.

OBJECTIVES: The aims of this study were to compute MVR in patients recruited for ORBITA and to evaluate interactions with prespecified endpoints.

METHODS: Hyperemic MVR was calculated using computational fluid dynamics (CFD) and compared against placebo-controlled changes in treadmill exercise time, patient-reported symptoms, physician-assessed symptoms, and dobutamine stress echocardiography scores at 6-week follow-up.

RESULTS: MVR_CFD was computed for 131 patients (66 undergoing PCI and 65 placebo). Median MVR_CFD was 1.38 mm Hg · min/mL (Q1-Q3: 0.89-2.09 mm Hg · min/mL). Baseline exercise time correlated with MVR_CFD (ordinal correlation coefficient = 0.20; 95% credible interval [CrI]: 0.18-0.22). For patients with low (20th centile) MVR_CFD, PCI increased exercise time by 48 seconds vs placebo (95% CrI: 6-92 seconds; Pr = 98.5%). Exercise time did not improve for patients with high (80th centile) MVR_CFD (16 seconds; 95% CrI: -29 to 61 seconds; probability of significant difference [Pr] = 75.2%), but evidence for an interaction was modest (Pr_interaction = 83.1%). Low MVR_CFD was also associated with a placebo-controlled benefit of PCI for likelihood of complete freedom from angina (Pr = 98.8%) and improvements in angina frequency (Pr = 97.8%) and stress echocardiography scores (Pr = 99.9%).

CONCLUSIONS: The placebo-controlled benefit of PCI was greater in patients with lower MVR_CFD, but interactions with symptom-based endpoints were modest. For patients with severe single-vessel disease taking optimal medical therapy, microvascular dysfunction may attenuate the functional and symptomatic benefits of PCI.

PMID:42043369 | DOI:10.1016/j.jcin.2026.01.305