Persistence of Microvascular Obstruction From Early to Late Gadolinium Enhancement Images on Cardiac MRI: Prognostic Utility After STEMI—Analysis of EARLY-MYO-CMR Registry Data

BACKGROUND. In patients undergoing cardiac MRI after ST-elevation myocardial infarction (STEMI), microvascular obstruction (MVO) often decreases in size between early gadolinium enhancement (EGE) and late gadolinium enhancement (LGE) images. Persistence of MVO between these images may indicate greater microvascular injury. OBJECTIVE. The purpose of this study was to evaluate the prognostic utility of measures of MVO persistence between EGE and LGE images in patients undergoing cardiac MRI after STEMI. METHODS. This retrospective study included 584 patients (mean age, 60 ± 11 [SD] years; 507 men, 77 women) enrolled in the multicenter Early Assessment of Myocardial Tissue Characteristics by CMR in STEMI (EARLY-MYO-CMR) registry from June 2017 to March 2023 who underwent cardiac MRI, including EGE and LGE imaging, within 1 week after percutaneous intervention for STEMI. Using semiautomated software, a radiologist measured MVO volumes (i.e., hypointense cores within hyperenhancing territories) on EGE and LGE images. The MVO persistence index was calculated as the ratio of MVO volume between LGE and EGE images. Patients were assigned to one of four MVO patterns (none [absent on EGE and LGE images]; reversible [present on EGE, absent on LGE images]; partially reversible [present on both images, persistence index < 40%]; persistent [present on both images, persistence index ≥ 40%]). Cox regression models were performed to predict major adverse cardiovascular event (MACE, including all-cause death, heart failure hospitalization, and reinfarction), adjusted for established clinical and MRI risk factors including static EGE and LGE MVO volumes. Propensity-score matching (PSM) analysis was performed between partially reversible and persistent MVO patterns. RESULTS. No MVO, reversible MVO, partially reversible MVO, and persistent MVO patterns were observed in 157, 133, 195, and 99 patients, respectively. In separate models, increased risk of MACE (n = 103) showed independent associations with MVO persistence index (HR per 10% increase: 1.36; p < .001) and persistent MVO pattern (HR vs no MVO pattern: 5.14; p < .001). Heart failure hospitalizations and reinfarctions also showed significant independent associations with MVO persistence index (HR: 1.26-1.45) and persistent MVO pattern (HR: 7.06-11.16). In PSM analysis (99 patients per group), MACE was independently associated with the persistent MVO pattern relative to the partially reversible MVO pattern (HR: 3.33; p = .004). CONCLUSION. MVO persistence between EGE and LGE images was a significant independent predictor of MACE. CLINICAL IMPACT. Measures of MVO dynamics provide prognostic information beyond standard static MVO measures.