Characteristics of patients presenting with myocardial infarction with non-obstructive coronary arteries (MINOCA) in Poland: data from the ORPKI national registry

Myocardial infarction (MI) with non-obstructive coronary arteries (MINOCA) is an important clinical problem especially in the era of extensive utilization of coronary angiography in MI patients. Its pathophysiology is poorly understood which makes diagnostics and treatment of MINOCA challenging in everyday clinical practice. The aim of the study was to assess characteristics of MINOCA patients in Poland based on data from the Polish National ORPKI Registry. In 2016, 49,893 patients with non-ST-segment elevation (NSTEMI) or ST-segment elevation (STEMI) myocardial infarction entered the ORPKI registry. MINOCA was defined as a non-obstructive coronary artery disease (CAD) and a lack of previous coronary revascularization. MINOCA was identified in 3924 (7.8%) patients and clinical presentation was more often NSTEMI than STEMI (MINOCA: 78 vs. 22%; obstructive CAD 51.1 vs. 48.9%; p < 0.0001). MINOCA patients were younger and more often females with significantly lower rates of diabetes, smoking, arterial hypertension, kidney disease, previous MI and previous stroke comparing to patients with obstructive CAD. Myocardial bridge was visualized in angiography more often in the MINOCA group (2.2 vs. 0.4%; p < 0.0001). Additional coronary assessment inducing fractional flow reserve, intravascular ultrasound, optical coherence tomography was marginally (< 1%) used in both groups. Periprocedural mortality was lower in MINOCA group (0.13% vs. 0.95%; p < 0.0001). MINOCA patients represent a significant proportion of MI patients in Poland. Due to multiple potential causes, MINOCA should be considered rather as a working diagnosis after coronary angiography and further efforts should be taken to define the cause of MI in each individual patient.