Calcified nodule as a cause of myocardial infarction with non-obstructive coronary artery disease

Abstract

Introduction: In patients presenting with myocardial infarction (MI), angiography most often reveals obstructive coronary artery disease (cAD) but 5-20% of patients with MI have non- obstructive cAD (MINOcA) at angiography. calcified nodule has been identified as a cause of MI with obstructive cAD but to date has not been reported as a cause of MINOcA. Intravascular ultrasound (IVUs) may find an underlying cause of MINOcA but has limited sensitivity for calcified nodule. We report a case of calcified nodule in a patient with MINOcA diagnosed by optical coherence tomography (Oct). case report: the patient was a 60-year-old male former smoker with cAD risk factors who presented with one hour of mid-sternal chest pain. troponin peaked at 1.28 ng/ml. Electrocardiogram of the patient was normal. coronary angiography showed minimal luminal irregularities. the patient underwent intracoronary Oct. On Oct, thrombus was identified overlying a calcified plaque with protrusion into the right coronary artery lumen. the appearance was characteristic of calcified nodule. cardiac MrI scan showed hypokinesis in the basal inferoseptal and basal anterior walls without late gadolinium enhancement. the patient was treated with dual antiplatelet therapy (aspirin and clopidogrel) and a high intensity statin. conclusion: these combined clinical, Oct and cMr findings confirm that calcified nodule is a cause of MINOcA and underscore the utility of intracoronary imaging to determine the pathophysiology of MINOcA. Even without intracoronary imaging, plaque disruption (e.g. plaque rupture, erosion, or calcified nodule) should be considered in cases of MINOcA based on prevalence of at least 35-40% in prior studies.