Relationship Between Post-Procedural Angiography-Derived Index of Microcirculatory Resistance and Periprocedural Myocardial Injury After Percutaneous Coronary Intervention

Background: Periprocedural myocardial injury (PMI) is a common complication of percutaneous coronary intervention (PCI). Elevated post-PCI index of microcirculatory resistance (IMR) has been linked to PMI. The angiography-derived IMR (angio-IMR) serves as a pressure-wire-free method to assess coronary microvascular function. This study aimed to establish the association between post-PCI angio-IMR and PMI. Methods and Results: We retrospectively analyzed 101 consecutive elective PCI cases where PMI diagnosis and post-PCI angio-IMR calculation were feasible. Angio-IMR was computed using computational flow and pressure simulations. Patients were categorized into 2 groups based on PMI status: PMI (n=33), and non-PMI (n=68). The PMI group had significantly higher post-PCI angio-IMR values than the non-PMI group (31.8±5.9 vs. 23.8±6.0; P