The HARP study is a multi-center, diagnostic observational study employing standardized imaging protocols in patients with MINOCA (MI with Non Obstructive Coronary Arteries) to determine the underlying diagnosis in each participant. Participants will be followed for recurrent clinical events, every 6 months, for a maximum of 10 years.

HARP is a multi-center, observational study which enrolls men and women with MI who are referred for cardiac catheterization. Eligible participants with MINOCA (defined as no stenosis of >50% in any major epicardial vessel) will undergo optical coherence tomography (OCT) at the time of diagnostic angiography and cardiac magnetic resonance imaging (CMR).

Participants will also have the option to enroll in the HARP-Platelet Sub-Study.

Inclusion Criteria:

• Acute ischemic symptoms compatible with diagnosis of MI, such as chest pain or anginal equivalent symptoms at rest or new onset exertional anginal equivalent symptoms

• Objective evidence of MI (either or both of the following):

  • Elevation of troponin to above the laboratory upper limit of normal
  • ST segment elevation of ≥1mm on 2 contiguous ECG leads

• Willing to provide informed consent and comply with all aspects of the protocol

• Age ≥ 21 years

Exclusion Criteria:

• Stenosis ≥50% of any major epicardial vessel on invasive angiography, as determined by the angiographer at the time of clinically ordered cardiac catheterization
• History of known obstructive coronary artery disease at angiography, including history of percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG)
• Recent use of vasospastic agents, such as cocaine, triptans, or ergot alkaloids (≤1 month)
• Alternate explanation for troponin elevation, such as hypertensive urgency, acute exacerbation of heart failure, chronic elevation due to kidney disease, pulmonary embolism, cardiac trauma
• Coronary dissection apparent on angiography
• Excessive coronary tortuosity which, in the angiographer's opinion, increases the risks of OCT
• eGFR<45 or contraindication to additional contrast needed for OCT in the opinion of the angiographer or treating physician
• Contraindication to MRI (including but not limited to ferromagnetic implants)
• Pregnancy
• Thrombolytic therapy for STEMI (qualifying event)

Men and women with MI and no coronary stenosis of 50% or greater on angiography, consecutive.

De-identified data will be shared after the end of the study.