CMR-derived global dispersion score predicts long-term outcomes after STEMI: insights from the 15-year follow-up of the MUSTELA RCT

Abstract Background The MUSTELA-RCT assessed the impact of thrombectomy during primary percutaneous coronary intervention (pPCI) in 208 patients with ST-segment elevation myocardial infarction (STEMI) and high thrombus burden. Initial findings demonstrated improved myocardial reperfusion and reduced microvascular obstruction with thrombectomy but no differences in infarct size at three months. Purpose To evaluate long-term outcomes of thrombectomy versus standard pPCI over a median follow-up of 15 years and identify Cardiac Magnetic Resonance (CMR) derived predictors of adverse events. Methods The original cohort of 208 patients was screened. Of these, 83 (39,9%) were lost to follow-up, 17 (8,2%) declined participation, and 97 (46,6%) were deceased. Eleven patients (5,3%) underwent comprehensive clinical assessment. Retrospective analysis of CMR late gadolinium enhancement (LGE) sequences was performed, and a novel metric termed "Global Dispersion Score" (GDS) was developed to quantify scar heterogeneity. GDS was derived from manually segmented scars on short-axis LGE images. Each voxel within the scar was categorized as non-enhanced, mildly enhanced, or hyper-enhanced based on signal intensity thresholds relative to normal myocardium (