Comparing coronary flow and microvascular measures before and after intracoronary nitroglycerin in people with angina and non-blocking coronary arteries
Analysis of Coronary Reactivity Testing With and Without Intracoronary Nitrate Testing
This study will try whether giving a small dose of nitroglycerin inside the coronary artery changes blood-flow and microvascular measurements in adults with angina but no major blockages.
Quick facts
| Phase | Not applicable |
|---|---|
| Study type | Interventional |
| Enrollment | 50 (estimated) |
| Ages | 18 Years and up |
| Sex | All |
| Sponsor | Baylor Research Institute Academic / other |
| Locations | 1 site (Plano, Texas) |
| Trial ID | NCT06896903 on ClinicalTrials.gov |
What this trial studies
This is a single-arm, multi-center prospective interventional study enrolling about 50 adults referred for coronary angiography for angina with non-obstructive coronary arteries (ANOCA/INOCA). Participants will undergo invasive coronary reactivity testing (CRT) with measurements of coronary flow reserve (CFR), index of microcirculatory resistance (IMR), transit time, Pa and Pd before any intracoronary nitrate. After an intracoronary nitroglycerin dose (200–500 mcg) the same CRT measurements will be repeated. The primary outcome is change in CFR before versus after nitroglycerin, with secondary outcomes including IMR, Pd, Pa, RRR, and transit times, analyzed using paired t-tests and generalized estimating equations.
Who should consider this trial
Good fit: Adults aged 18 or older who have angina with non-obstructive coronary arteries (ANOCA/INOCA) and are referred for coronary angiography and able to give informed consent are ideal candidates.
Not a fit: Patients with obstructive coronary disease, recent coronary stents or bypass, recent use of long-acting nitrates or PDE-5 inhibitors, pregnant people, or those unable to consent are unlikely to benefit or be eligible.
Why it matters
Potential benefit: If successful, the study could clarify how intracoronary nitroglycerin alters CRT measurements and improve interpretation of invasive testing to guide treatment for microvascular angina.
How similar studies have performed: Intracoronary nitrates are commonly used to distinguish epicardial spasm and standardize physiology measurements, but paired prospective CRT comparisons before and after nitroglycerin are limited.
Eligibility criteria
Show full inclusion / exclusion criteria
Inclusion Criteria: 1. Aged 18 or older 2. Patient being evaluated for ANOCA or INOCA 3. Clinical suspicion for angina 4. Patient should be able to comply with the protocol. 5. Provide written informed consent before study participation. Exclusion Criteria: 1. Existing coronary artery disease 2. Previous percutaneous interventions within the coronaries 3. Current use (within 48 hours) of long-acting nitrate therapies 4. Current use (within 48 hours) of PDE-5 inhibitors (sildenafil, tadalafil) 5. Any other condition or co-morbidity which, in the opinion of the investigator or operator, may pose a significant hazard to the subject if he or she is enrolled in the study. 6. Children below 18 years, prisoners, pregnant people and patients who are unable to provide consent are excluded.
Where this trial is running
Plano, Texas
- Baylor Scott & White The Heart Hospital - Plano — Plano, Texas, United States (Recruiting)
Study contacts
- Study coordinator: Bonnie Ostergren
- Email: Bonnie.Ostergren@bswhealth.org
- Phone: 469-814-4181
How to participate
- Review the eligibility criteria above with your treating physician.
- Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
- Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.