Analysis of Coronary Reactivity Testing With and Without Intracoronary Nitrate Testing (CRT-NITRO)

Baylor Scott and White Health (BSWH)

Status: Enrolling

Conditions: INOCA (Ischemia With Non Obstructive Coronary Artery Disease); ANOCA - Angina With Non-obstructive Coronary Arteries

Treatments: Diagnostic Test: Coronary reactivity testing with and without nitrates

Study type: Interventional

Funder types: Other

Identifiers

NCT06896903

025-193

Details and patient eligibility

About

This single-arm, multi-center, prospective study will assess the coronary flow reserve (CFR), index of microcirculatory resistance (IMR), and determinants thereof (transit time, Pa, Pd) in patients before and after intracoronary nitroglycerine.

Full description

This will be a single arm, multi-center, prospective interventional study. We will approach, consent, and enroll patients referred to the cardiac catheterization laboratory for coronary angiography for the indication of angina without obstructive coronary artery disease (CAD; lesions <50%, fractional flow reserve (FFR) >0.80, or non-hyperemic pressure index (RFR) <0.89). Patients will undergo invasive assessment with CRT first without IC nitrates followed by a dose of 200-500 mcg of intracoronary nitrates and repeat CRT.

Approximately 50 patients undergoing coronary angiography for evaluation of ANOCA or INOCA will be consented for this study.

The primary outcome will be comparing the variables assessed by CRT with the primary outcome being CFR before and after nitroglycerin administration.

The secondary outcomes will be IMR, Pd, Pa, RRR, and transit times before and after nitrates.

These variables will be compared to one another using paired t-tests and generalized estimating equations.

Enrollment: 50 estimated patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

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.

Trial design

Primary purpose: Other

Allocation: N/A

Interventional model: Single Group Assignment

Masking: None (Open label)

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50 participants in 1 patient group

Coronary Reactivity Testing with and without intracoronary nitroglycerine

Experimental group

Description:

CRT will be performed in the left anterior descending and right coronary arteries. The following measures will be obtained in each of the coronaries first without intracoronary nitrates followed by a dose of 200-500 mcg of intracoronary nitrates and repeat measurements: * Coronary flow reserve (CFR) (normal \> 2.0) * Index of microvascular resistance (IMR) (normal \<25) * Resting ratio of distal coronary pressure to aortic pressure (Pd/Pa) (normal \< 0.91) * Resting and hyperemic (using intravenous adenosine) transit time (Tm) * Resting full-cycle ratio (RFR) * Hyperemic (using intravenous adenosine) fractional flow reserve (FFR) * Resistive reserve ratio (RRR)

Treatment:

Diagnostic Test: Coronary reactivity testing with and without nitrates