Analysis of Coronary Reactivity Testing With and Without Intracoronary Nitrate Testing

Summary

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.

Detailed 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.

Eligibility Criteria

Interventions