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: 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 years; 507 male, 77 female) enrolled in the multicenter EARLY-MYO-CMR registry from June 2017 to March 2023 who underwent cardiac MRI, including EGE and LGE images, 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]; reversible [present on EGE, absent on LGE]; partially reversible [present on both, persistence index <40%]; persistent [present on both, persistence index ≥40%]). Cox regression models were performed to predict major adverse cardiovascular events (MACE: all-cause death, heart failure hospitalization, 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 relative to 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.