RESUMO
The acronym MINOCA (Myocardial Infarction with Non-Obstructive Coronary Arteries) refers to myocardial infarction with normal or near-normal coronary arteries on invasive angiography. The broad spectrum of pathological mechanisms responsible for myocardial injury in MINOCA makes defining the exact underlying etiology challenging. We report the uncommon case of an acute myocardial infarction with normal coronary arteries suggestive of MINOCA caused by paradoxical coronary embolism due to a wide right-to-left shunting through a patent fossa ovalis. Integrated multimodality imaging diagnostic work-up, including cardiac magnetic resonance, transesophageal contrast echocardiography, and transcranial contrast Doppler, has been crucial for identifying the most likely mechanism underlying MINOCA.
RESUMO
PURPOSE: To evaluate the ability of coronary computed tomography angiography (CCTA) with model-based iterative reconstruction (MBIR) algorithm in detecting significant coronary artery stenosis compared with invasive coronary angiography (ICA). MATERIAL AND METHODS: We retrospectively identified 55 patients who underwent CCTA using the MBIR algorithm with evidence of at least one significant stenosis (≥ 50%) and an ICA within three months. Patients were stratified based on calcium score; stenoses were classified by type and by coronary segment involved. Dose-length-product was compared with the literature data obtained with previous reconstruction algorithms. Coronary artery stenosis was estimated on ICAs based on a qualitative method. RESULTS: CCTA data were confirmed by ICA in 89% of subjects, and in 73% and 94% of patients with CS < 400 and ≥ 400, respectively. ICA confirmed 81% of calcific stenoses, 91% of mixed, and 67% of soft plaques. Both the dose exposure of patients with prospective acquisition (34) and the exposure of the whole population were significantly lower than the standard of reference (p < 0.001 and p = 0.007). CONCLUSIONS: CCTA with MBIR is valuable in detecting significant coronary artery stenosis with a solid reduction of radiation dose. Diagnostic performance was influenced by plaque composition, being lower compared with ICA for patients with lower CAC score and soft plaques; the visualisation of an intraluminal hypodensity could cause false positives, particularly in D1 and MO segments.
RESUMO
BACKGROUND: We present a rare case of anomalous origin of the left coronary artery from the pulmonary artery syndrome in an elderly man, and we describe coronary computed tomographic angiographic imaging findings to improve diagnostic confidence for the evaluation of this uncommon coronary artery anomaly. CASE PRESENTATION: A 70-year-old Caucasian man came to our hospital with slight limitation of physical activity (New York Heart Association class II). He was asymptomatic for angina, syncope, and palpitations. Cardiac magnetic resonance imaging was performed after echocardiography because a hypertrophic cardiomyopathy was suspected; a plausible coronary artery anomaly was demonstrated as collateral evidence. Subsequently, coronary computed tomographic angiography showed the anomalous origin of left coronary artery from the pulmonary artery; the coronary vessels appeared markedly dilated and tortuous. Dilated intercoronary vessels along the epicardial surface of the heart and dilated bronchial arteries, corresponding to collateral pathways, were observed. Left ventricular hypertrophy, delayed subendocardial enhancement, and mitral insufficiency were better evaluated on magnetic resonance images. Invasive coronary angiography confirmed the main findings. Given the patient's age and clinical performance, surveillance with medical management was considered appropriate, and surgical repair was avoided. CONCLUSIONS: Confidence with the anatomic pattern and clinical significance of this anomalous condition is necessary to improve cardiac imaging evaluation ability. In our patient, coronary computed tomographic angiography proved to be a reliable imaging approach, superior to invasive coronary angiography in terms of diagnostic performance and patient safety.
