Non-contrast-enhanced multiparametric cardiac magnetic resonance reveals coronary microvascular functional and structural obstruction after percutaneous coronary intervention

Objectives: Coronary microvascular functional and structural obstructions (CMVO) after percutaneous coronary intervention (PCI) are a major cause of poor clinical outcomes in patients with acute coronary syndrome. This study aimed to noninvasively diagnose the presence of CMVO using non-contrast multiparametric cardiac magnetic resonance (CMR) in patients with acute myocardial infarction (AMI) who underwent PCI. Methods: We retrospectively enrolled consecutive patients with AMI who underwent PCI and subsequent acute-phase CMR at our hospital. The patients were divided into two groups: those with and those without CMVO. The top five clinical and CMR parameters were extracted based on their correlation coefficients with the presence of CMVO. Receiver-operator characteristic (ROC) curves and area under the curve (AUC) were generated to compare the diagnostic performance of CMVO detection using the Top_5 clinical parameters, Top_5 CMR parameters, and CMR left ventricular (LV) volume and structure parameters. Differences in the AUC between parameters were compared using the DeLong test. Results: Forty-eight patients (40 men and 8 women; mean age, 66 ± 12 years) were included in the study. For CMVO detection, the ROC curves of Top_5 clinical parameters, Top_5 CMR parameters, and CMR LV volume and structure parameters demonstrated AUCs of 0.87, 1.00, and 0.72, respectively. The Top_5 CMR parameters exhibited the highest AUC, showing significant differences compared to the other groups. Conclusion: Non-contrast enhanced multiparametric CMR allows the diagnosis of CMVO with high accuracy and without kidney burden and is expected to be a useful marker for risk stratification, patient management, and treatment decision-making. Key Points: Question CMVO following PCI is difficult to diagnose through coronary angiography and can lead to adverse outcomes. Findings Non-contrast enhanced multiparametric CMR imaging has the potential to accurately diagnose CMVOs and further identify their location and extent. Critical relevance Non-contrast enhanced multiparametric CMR enables accurate, noninvasive diagnosis of CMVO, and provides both organic and functional myocardial information. These findings are crucial for diverse CMVO etiologies that require individualized treatment, and may help risk stratification, patient management, and treatment decision-making.