Monocyte Subsets Are Differently Associated with Infarct Size, Left Ventricular Function, and the Formation of a Potentially Arrhythmogenic Scar in Patients with Acute Myocardial Infarction.

To investigate the role of classical (CLM, CD14++CD16-), intermediate (INTM, CD14++CD16+), and non-classical (Non-CLM, CD14+CD16++) monocytes in scar formation after ST-elevation myocardial infarction (STEMI), evaluated with cardiac magnetic resonance (CMR). One hundred two patients with a first STEMI had serial blood analyses after 1, 3, and 7 days. A CMR was performed at 7 days and 6 months, depicting scar core (CO), border zone (BZ), and the presence of BZ channels. CLM and INTM levels progressively decreased, correlated with the scar mass, CO, and BZ at 7 days and 6 months (p < 0.05), and inversely with left ventricular ejection fraction (LVEF, p < 0.01). Non-CLM levels gradually increased, correlated with BZ mass and the presence of BZ channels at 7 days and 6 months (p < 0.001).CLM and INTM are associated with infarct size and inversely with LVEF, whereas Non-CLM are associated with BZ mass and the presence of potentially arrhythmogenic substrate.