Implanting a device to improve blood flow in patients with angina and no blocked arteries

REducing Microvascular Dysfunction in Patients With Angina, Ischaemia and unobstructED coronarY Arteries - a PILOT Study

Not applicable Interventional Imperial College London · NCT05492110

This study is testing a new device to see if it can help people with angina and no blocked arteries feel better by improving blood flow to their heart.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment54 (estimated)
Ages18 Years and up
SexAll
SponsorImperial College London Academic / other
Locations1 site (London)
Trial IDNCT05492110 on ClinicalTrials.gov

What this trial studies

This study aims to evaluate the feasibility and effectiveness of the Coronary Sinus Reducer for treating patients suffering from ischaemia and non-obstructed coronary arteries, specifically those with coronary microvascular dysfunction. It will involve a randomized, double-blinded, sham-controlled pilot approach to assess the acceptability of the device implantation and its impact on myocardial perfusion. Additionally, a nested mechanistic substudy will investigate the physiological changes in the coronary microcirculation that may explain improvements in symptoms and quality of life. The study seeks to address a significant unmet clinical need for patients with refractory angina.

Who should consider this trial

Good fit: Ideal candidates are adults over 18 with ongoing symptomatic angina for at least three months despite maximum tolerated doses of two anti-anginal medications.

Not a fit: Patients with significant epicardial coronary artery disease or those who have had recent coronary interventions may not benefit from this study.

Why it matters

Potential benefit: If successful, this treatment could significantly alleviate symptoms and improve quality of life for patients with refractory angina.

How similar studies have performed: While the approach of using a Coronary Sinus Reducer is novel, similar studies targeting coronary microvascular dysfunction have shown promise, indicating potential for success.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

1. Age \>18 years
2. Ongoing symptomatic angina, CCS Class II-IV, for ≥3 months despite background treatment with at least two anti-anginal drug at the maximal tolerated dose.
3. Patients willing to consider no change in anti-anginal drug treatment for the duration of their participation in the trial.
4. Unobstructed coronary arteries with ≤50% epicardial stenoses demonstrated on coronary angiography.
5. Stress-induced hypoperfusion on CMR (Global MPR ≤ 2.2).
6. Willingness to comply with the specified follow-up evaluation and to be contactable during the period of the trial.
7. Understands the nature of the trial procedures and provides written informed consent.

Exclusion Criteria:

1. Epicardial CAD in a main coronary artery (stenoses \>50%, RFR≤0.92 or FFR≤0.80), coronary artery bypass grafting, or myocardial infarction (MI).
2. Previous PCI within 6 months
3. PCI with stent insertion for acute MI or chronic total occlusion (CTO)
4. Abnormal coronary sinus anatomy (tortuosity, aberrant branch, persistent left superior vena cava)
5. Coronary sinus diameter at site of implant \<9.5mm or \>13mm
6. Mean right atrial pressure \<15mmHg at time of implantation
7. Any structural heart disease including left ventricular hypertrophy; cardiomyopathy; severe valvular heart disease; previous valve replacement; myocardial bridge on angiography; LVEF\<45% by CMR.
8. Clinically or angiographically diagnosed coronary vasospasm
9. Previous hospitalisation for decompensated heart failure
10. Pacemaker or defibrillator electrode in the right atrium, right ventricle or coronary sinus
11. Documented arrhythmia requiring planned implantation of a permanent pacemaker or defibrillator
12. Chronic kidney disease (creatinine \>200 micromol/L; established on renal replacement therapy; functioning renal transplant)
13. Haemoglobin \<80g/L
14. Contraindications to receiving dual antiplatelet therapy
15. Severe chronic obstructive pulmonary disease (FEV1 \<55% predicted)
16. Moribund patients with life expectancy \< 1year
17. Known allergy to nickel or steel
18. Current enrolment in another investigational device or drug trial
19. Contraindications to CMR or receiving intravenous adenosine
20. Pregnancy

Where this trial is running

London

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Refractory AnginaMicrovascular AnginaMicrovascular Coronary Artery DiseaseCoronary DiseaseAngina PectorisAngina pectorisRefractory anginaMicrovascular angina
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.