The influence of coronary plaque morphology assessed by optical coherence tomography on final microvascular function after stenting in patients with ST-elevation myocardial infarction

Objectives The index of microcirculatory resistance (IMR) provides a reproducible assessment of the status of coronary microvasculature in patients with ST-elevation myocardial infarction (STEMI). Frequency-domain optical coherence tomography (FD-OCT) enables detailed assessment of the morphology of coronary plaque. We sought to determine the influence of the initial culprit coronary plaque anatomy within the infarct-related artery on IMR after stenting in STEMI. Patients and methods In 25 STEMI patients IMR was measured immediately before and after stent implantation. FD-OCT imaging was performed at the same time points and atherothrombotic volume (ATV) before stenting, prolapsed+ floating ATV after stenting and.ATV was measured using three different strategies. Results There were no relationships between preprocedural IMR and FD-OCT parameters. Prestenting IMR was related only to pain to wire time (P: 0.02). Irrespective of the method adopted, the final IMR was related to prestenting ATV (rho: 0.44, P: 0.03 for method I, rho: 0.48, P: 0.02 for method II and rho: 0.30, P: 0.06 for method III) and Delta ATV (rho: 0.41, P: 0.04 for method II and rho: 0.44, P: 0.03 for method III). Conclusion IMR measured before stenting is independent of the appearances of the culprit coronary plaque within the infarct-related artery. IMR after stenting, and more importantly, the change in IMR after stenting, reflect the degree of distal embolization during stent implantation. Copyright (C) 2017 Wolters Kluwer Health, Inc. All rights reserved.