This study aims to determine the impact of stent post-dilation (PD) with NC balloons at high pressures on coronary microcirculation during PPCI by measuring the index of microcirculatory resistance (IMR) pre and post stent post-dilatation. Pre and post PD, an optical coherence tomography (OCT) study will be performed to assess stent deployment and identify parameters that predict the changes in IMR.