关键词： Acute ST-segment elevation myocardial infarction   Late gadolinium enhancement   Myocardial fibrosis   Cardiac magnetic resonance  

摘要： Background Myocardial fibrosis is a prevalent pathological hallmark of a diverse range of chronic and acute cardiovascular disorders. However, the relevant literature currently provides limited evidence regarding the determinants of myocardial fibrosis severity in patients with new-onset ST-elevation myocardial infarction (STEMI) following successful emergent percutaneous coronary intervention (PCI) utilizing contrast-enhanced cardiac magnetic resonance imaging (CE-CMR). Methods We prospectively enrolled a cohort of 78 patients who presented with new-onset ST-segment elevation myocardial infarction and who underwent successful emergent PCI within 12 h from the onset of symptoms. Late gadolinium-enhanced LGE (LGE) was quantified via CE-CMR, and patients were categorized into two groups on the basis of the median LGE value. Results The median LGE was 16% (IQR 12 to 24). Compared with patients with LGE below the median (n = 37), those with LGE above the median (n = 41) presented significantly reduced left ventricular global radial strain(GRS), global circumferential strain(GCS), and global longitudinal strain(GLS) (all p < 0.05). The infarcted radial segment (IRS), infarcted circumferential segment (ICS) and infarcted longitudinal segment (ILS) were significantly reduced in patients with greater LGE (all p < 0.05). The occurrence rates of microvascular obstruction (MVO) (p < 0.001) and wall motion abnormality (WMA) (p < 0.01) were significantly greater in patients with a greater extent of LGE, despite successful reperfusion therapy. LGE exhibited a moderate negative correlation with the global circumferential segment (r=-0.547, p < 0.001) and a weak negative correlation with both the global radial segment and the global longitudinal segment (r=-0.434, p < 0.001;r=-0.437, p < 0.001). In the multivariable linear regression analysis model, the Gensini score (beta = 0.258;p < 0.01), LVEF% (beta=-0.269;p < 0.05), MVO (beta = 0.343;p < 0.001) and GRS (beta = 0.227;p < 0.05)

关键词： MRSA   ST5-SCCmecI   geographic divergence   earthquake   tsunami   heavy metals  

摘要： Methicillin-resistant Staphylococcus aureus (MRSA) is a major public health menace. The global spread of MRSA is characterized by successive waves of epidemic clones dominating specific geographical regions. The acquisition of genes encoding resistance to heavy metals (HMRGs) is thought to be a key feature in the geographic divergence of MRSA. However, the cause-effect relationship between the presence of HMRGs and the divergence of MRSA clones remains to be clarified. In this study, we assessed the role that HMRGs may have played in the evolutionary divergence of the MRSA ST5-SCCmecI lineage in Latin America. We conducted a genomic characterization of 113 MRSA clinical isolates from six Latin American healthcare centers, including 53 isolates collected from two cities in Chile (Santiago and Concepci & oacute;n). We found a plasmid (pSCL4752) harboring arsenic, cadmium, and mercury resistance genes in 65% (n = 71) of the ST5-SCCmecI isolates. We also observed a geographic divergence associated with the presence of pSCL4752 in Chilean isolates, with a higher frequency in isolates from Concepci & oacute;n (88%) compared to Santiago (29%). Interestingly, a molecular clock analysis revealed that this divergence occurred in the aftermath of an 8.8 Mw earthquake and tsunami that struck the Concepci & oacute;n area in 2010. Moreover, our results demonstrate that the carriage of pSCL4752 can be beneficial or detrimental for ST5-SCCmecI isolates, depending on the environmental availability of these heavy metals. Our results suggest that the divergence of the ST5-SCCmecI MRSA lineage in Latin America could have been fostered by environmental disasters and influenced by the presence/absence of HMRGs harbored in a plasmid.