From Myocardial Infarction with Non-Obstructive Coronary Arteries (MINOCA) to Chronic Coronary Syndrome: Clinical Diagnostic Use of Laser Doppler Flowmetry in Coronary Microvascular Dysfunction.

BACKGROUND MINOCA is defined as myocardial infarction with non-obstructive coronary changes, or the absence of atherosclerotic coronary plaques (less than 50%). The long-term prognosis of these patients is as poor as for those with obstructive coronary disease. Possibilities for treatment follow-up and improvement are still lacking. This case report provides a retrospective analysis of a case of MINOCA that transformed into chronic coronary syndrome (CCS). CASE REPORT A 40-year-old patient had acute coronary syndrome without atherosclerotic changes in the great epicardial coronary arteries, but with slow coronary flow in the left anterior descending coronary artery in 2011 and 2014. Two-dimensional transthoracic echocardiography showed no echocardiographic impairment of myocardial contractility. The comorbidities were visceral obesity, dyslipidemia, and smoking history. After the addition of a calcium channel blocker and trimetazidine to standard therapy, there were no anginal symptoms. In 2019, during a regular health check-up, contrast echocardiography showed a slow rinse of contrast in the apical and medial/distal anterolateral segment with reduced longitudinal strain in the same myocardial segments. Laser Doppler flowmetry (LDF) showed impaired microcirculatory function in the skin microcirculation. CONCLUSIONS This case report highlights: 1) use of the non-invasive, inexpensive, and easy-to-use LDF technique for microcirculatory dysfunction confirmation; 2) follow-up of MINOCA to CCS transition; 3) visceral obesity as a risk factor for MINOCA and CCS; and 4) the role of trimetazidine in CCS.