Impella effects on reverse myocardial remodeling in anterior ST-elevation myocardial infarction: insights from a comprehensive analysis of acute and chronic MRI findings

Background: Late adverse myocardial remodeling after ST elevation myocardial infarction (STEMI) is strongly associated with cardiac death. Global Longitudinal strain (GLS) and circumferential diastolic strain rate (CDSR) derived cardiovascular magnetic resonance imaging (CMRI) is a powerful predictor of late myocardial remodeling. However, the Impella’s effects on CMRI after STEMI are not fully understood. Research design and methods: We retrospectively compared the CMRI in the acute (18 [14–22] vs. 14 [6–22] days, p = 0.43) and chronic phases (118 [102–242] vs. 117 [101–202] days, p = 1.0) after anterior STEMI. Results: Five patients received Impella before percutaneous coronary intervention (PCI), and seven underwent intra-aortic balloon pumping (IABP). There were no significant differences in the peak creatine kinase levels (2595 [2069 -12,932] vs. 4372 [2941–5601] IU/L, p = 0.76) and LVEF upon admission (51 ± 11 vs. 50 ± 9%, p = 1.0). The Impella group had significantly better acute CMRI-derived LVEF (49 ± 10 vs. 35 ± 7%, p = 0.02) and CDSR (0.9 ± 0.2 vs. 0.5 ± 0.3 s^{− 1}, p = 0.018). In the chronic phase, the CMRI-derived LVEF and GLS were significantly higher in the Impella group (54 ± 9 vs. 39 ± 5%, p = 0.01; −9.9 ± 1.3 vs. −6.5 ± 2.2%, p = 0.01). Conclusions: The Impella implantation led to better LVEF and CDSR in the acute phase than IABP and better maintenance of both the LVEF and GLS through the chronic phase.