Study of Lesion-Specific Invasive Haemodynamic Angina Thresholds (ORBITA-SOLAR)

February 16, 2026 updated by: Imperial College London
ORBITA-SOLAR is an invasive physiological cardiac catheterisation study that aims to determine whether different coronary stenoses have different angina thresholds. The angina threshold is defined as the amount of coronary flow reduction required to reproduce symptoms. Sixty patients with symptoms of stable angina and 2 coronary artery stenoses amenable to percutaneous coronary intervention (PCI) will be recruited. This study will use intra-coronary balloon inflation during supine exercise on an ergometer to measure the fractional flow reserve (FFR) and non-hyperemic pressure ratio (NHPR) that relates to angina onset, in real time, at the location of each stenosis.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

60

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

  • United Kingdom
      • Basildon, United Kingdom
        • Not yet recruiting
        • Mid and South Essex NHS Foundation Trust
        • Contact:
      • Bournemouth, United Kingdom
        • Not yet recruiting
        • University Hospitals Dorset NHS Foundation Trust
        • Contact:
      • London, United Kingdom
        • Recruiting
        • Imperial College Healthcare NHS Trust
        • Contact:
      • London, United Kingdom
        • Not yet recruiting
        • Royal Free London NHS Foundation Trust
        • Contact:
      • London, United Kingdom
        • Not yet recruiting
        • St George's University Hospitals NHS Foundation Trust
        • Contact:
      • Portsmouth, United Kingdom

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Eligibility for PCI due to angina or angina-equivalent symptoms on exertion

  2. 2 severe epicardial stenoses in a major coronary artery, defined as:

    1. ≥70% stenosis in a coronary artery with ≥2.5mm diameter, on invasive coronary angiography (ICA)
    2. Severe stenosis in a vessel with ≥2.5mm diameter, on CTCA

  3. Evidence of ischaemia on an invasive or non-invasive test, including:

    1. Physiological test during invasive coronary angiography (ICA)
    2. Dobutamine stress echocardiography (DSE)
    3. Stress perfusion cardiac magnetic resonance (CMR)
    4. Myocardial perfusion scintigraphy (MPS)
    5. Fractional flow reserve computed-tomography (FFR-CT)

Exclusion Criteria:

  1. Age <18 years
  2. Acute coronary syndrome within 3 months
  3. Previous coronary artery bypass graft
  4. Significant left main stem disease
  5. Single lesion amenable to PCI
  6. Chronic total occlusion of the target artery
  7. Moderate to severe valve disease
  8. LVEF ≤40%, contraindication to PCI or drug-eluting stents
  9. PCI performed with drug-eluting balloons without stenting
  10. Contraindication to antiplatelet therapy
  11. Contraindication to adenosine
  12. Physical inability to exercise with an ergometer
  13. Femoral artery access
  14. Pregnancy
  15. Inability to consent

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Diagnostic
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Patients with stable coronary artery disease
  1. Symptoms of stable angina
  2. Evidence of ischaemia on an invasive or non-invasive test
  3. Two coronary stenoses amenable to percutaneous coronary intervention (PCI)
Procedure: Percutaneous coronary intervention (PCI)
Clinically indicated PCI for the management of stable angina
Diagnostic test: Measurement of the angina threshold
Following stenting, the order in which to perform the angina threshold assessment at the location of each stent will be randomised. A non-compliant balloon with gradually be inflated over a pressure wire within the deployed stent to re-introduce stenosis. Simultaneously, the participant will exercise on a supine ergometer. At the point when angina is reproduced, the patient will rest and further balloon inflation will stop. Physiological measurements using the pressure wire will be taken with the inflated balloon in situ. This will represent the invasive physiological angina threshold. The balloon will then be deflated and removed. These steps will be repeated at the location of the second stent.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Intra-individual difference in FFR and NHPR angina thresholds
Time Frame: Intra-procedural
Difference in invasively measured physiological angina thresholds at the site of the 2 stents within each participant, stratified by vascular territory and lesion location along a vessel.
Intra-procedural

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Correlation of the angina threshold with other invasive physiological assessments
Time Frame: Intra-procedural
Including coronary artery disease pattern (focal, diffuse or mixed), presence of microvascular disease (IMR and CFR), extent of collateral flow (CFI), and pre- and post-PCI ischaemia (FFR and RFR)
Intra-procedural
Correlation of the angina threshold with anatomical characteristics assessed with computed tomography coronary angiography (CTCA)
Time Frame: 14 days
Including proportion of myocardial mass subtended (%), coronary artery territory (LAD, LCx, RCA), and lesion location along a vessel (proximal, mid, distal)
14 days
Correlation of the angina threshold with anatomical characteristics assessed with quantitative coronary angiography (QCA)
Time Frame: 14 days
Including lesion length (mm), minimum lumen diameter, (mm) percent diameter stenosis (%), and reference vessel diameter (mm)
14 days
Correlation of the angina threshold with anatomical characteristics assessed with intravascular imaging
Time Frame: Intra-procedural
Including lesion length (mm), pre-PCI minimum lumen area (mm2), post-PCI minimum stent area (mm2), reference vessel cross-sectional area (mm2), plaque characteristics (lipid, fibrotic, calcific)
Intra-procedural
Correlation of the angina threshold with features on a stress perfusion cardiac magnetic resonance imaging (CMR) scan
Time Frame: 14 days
Including myocardial perfusion reserve (MPR), number of segments of infarcted myocardium, and percentage mural infarct depth (%)
14 days
Correlation of the angina threshold with baseline symptoms, quality of life and pain perception
Time Frame: 14 days
Assessed with the ORBITA-app and validated questionnaires (SAQ, EQ5D5L)
14 days

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Imperial College London

Collaborators

Royal Free Hospital NHS Foundation Trust
Mid and South Essex NHS Foundation Trust
Portsmouth Hospitals NHS Trust
Imperial College Healthcare NHS Trust
St George's University Hospitals NHS Foundation Trust
University Hospitals Dorset NHS Foundation Trust

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

February 10, 2026

Primary Completion (Estimated)

December 1, 2028

Study Completion (Estimated)

December 1, 2028

Study Registration Dates

First Submitted

January 19, 2026

First Submitted That Met QC Criteria

January 27, 2026

First Posted (Actual)

February 4, 2026

Study Record Updates

Last Update Posted (Actual)

February 18, 2026

Last Update Submitted That Met QC Criteria

February 16, 2026

Last Verified

February 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 199514

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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