Reconsidering treatment guidelines for acute myocardial infarction during the COVID-19 pandemic.

BACKGROUND: COVID-19 affects healthcare resource allocation, which could lead to treatment delay and poor outcomes in patients with acute myocardial infarction (AMI). We assessed the impact of the COVID-19 pandemic on AMI outcomes. METHODS: We compared outcomes of patients admitted for acute ST-elevation MI (STEMI) and non-STEMI (NSTEMI) during a non-COVID-19 pandemic period (January-February 2019; Group 1, n = 254) and a COVID-19 pandemic period (January-February 2020; Group 2, n = 124). RESULTS: For STEMI patients, the median of first medical contact (FMC) time, door-to-balloon time, and total myocardial ischemia time were significantly longer in Group 2 patients (all p < 0.05). Primary percutaneous intervention was performed significantly more often in Group 1 patients than in Group 2 patients, whereas thrombolytic therapy was used significantly more often in Group 2 patients than in Group 1 patients (all p < 0.05). However, the rates of and all-cause 30-day mortality and major adverse cardiac event (MACE) were not significantly different in the two periods (all p > 0.05). For NSTEMI patients, Group 2 patients had a higher rate of conservative therapy, a lower rate of reperfusion therapy, and longer FMC times (all p < 0.05). All-cause 30-day mortality and MACE were only higher in NSTEMI patients during the COVID-19 pandemic period (p < 0.001). CONCLUSIONS: COVID-19 pandemic causes treatment delay in AMI patients and potentially leads to poor clinical outcome in NSTEMI patients. Thrombolytic therapy should be initiated without delay for STEMI when coronary intervention is not readily available; for NSTEMI patients, outcomes of invasive reperfusion were better than medical treatment.

The impact of admission modes on the treatment outcome and in-hospital mortality rate of STEMI patients undergoing PPCI.

The current research on ST elevation myocardial infarction (STEMI) patients has been mostly limited to Door-to-Balloon (D-to-B) time. This study aimed to compare the effects of different hospital admission modes to on the time metrics of patients undergoing primary percutaneous coronary intervention (PPCI). It also examined the effects of these modes on in-hospital mortality and other influencing factors. The goal was to prompt healthcare facilities at all levels, including chest hospitals, the Centers for Disease Control and Prevention (CDC), and communities to take measures to enhance the treatment outcomes for patients with STEMI. A total of 1053 cases of STEMI patients admitted to Tianjin Chest Hospital from December 2016 to December 2023 and successfully underwent PPCI were selected for this study. They were divided into three groups based on the admission modes: the ambulances group (363 cases), the self-presentation group (305 cases), and the transferred group (385 cases). Multivariate logistic regression was used to explore the impact of different modes of hospital admission on the standard-reaching rate of key treatment time metrics. The results showed that the S-to-FMC time of transferred patients (OR = 0.434, 95% CI 0.316-0.596, P < 0.001) and self-presentation patients (OR = 0.489, 95% CI 0.363-0.659, P < 0.001) were more likely to exceed the standard than that of ambulance patients; The cath lab pre-activation time of self-presented patients was also less likely to meet the standard than that of ambulance patients (OR = 0.695, 95% CI 0.499-0.967, P = 0.031); D-to-W time of self-presentation patients was less likely to reach the standard than that of ambulance patients (OR = 0.323, 95% CI 0.234-0.446, P < 0.001);However, the FMC-to-ECG time of self-presentation patients was more likely to reach the standard than that of ambulance patients (OR = 2.601, 95% CI 1.326-5.100, P = 0.005). The Cox proportional hazards model analysis revealed that for ambulance patients, the time spent at each key treatment time point is shorter, leading to lower in-hospital mortality rate (HR0.512, 95% CI 0.302-0.868, P = 0.013) compared to patients admitted by other means. We found that direct arrival of STEMI patients to the PCI hospital via ambulance at the onset of the disease significantly reduces the S-to-FMC time, FMC-to-ECG time, D-to-W time, and catheterization room activation time compared to patients who self-present. This admission mode enhances the likelihood of meeting the benchmark standards for each time metric, consequently enhancing patient outcomes.

Circulating exosomal lncRNA contributes to the pathogenesis of spinal cord injury in rats.

Exosome-derived long non-coding RNAs (lncRNAs) are extensively engaged in recovery and repair of the injured spinal cord, through different mechanisms. However, to date no study has systematically evaluated the differentially expressed lncRNAs involved in the development of spinal cord injury. Thus, the aim of this study was to identify key circulating exosome-derived lncRNAs in a rat model of spinal cord injury and investigate their potential actions. To this end, we established a rat model of spinal cord hemisection. Circulating exosomes were extracted from blood samples from spinal cord injury and control (sham) rats and further identified through Western blotting and electron microscopy. RNA was isolated from the exosomes and sequenced. The enrichment analysis demonstrated that there were distinctively different lncRNA and mRNA expression patterns between the two groups. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis and Gene Ontology (GO) functional analysis were performed to determine the possible involvements of upregulated and downregulated lncRNAs in various pathways and different biological processes, as well as their cellular locations and molecular functions. Furthermore, quantitative reverse transcription-polymerase chain reaction showed that the expression of five lncRNAs--ENSRN0T00000067908, XR_590093, XR_591455, XR_360081, and XR_346933--was increased, whereas the expression of XR_351404, XR_591426, XR_353833, XR_590076, and XR_590719 was decreased. Of note, these 10 lncRNAs were at the center of the lncRNA-miRNA-mRNA coexpression network, which also included 198 mRNAs and 41 miRNAs. Taken together, our findings show that several circulating exosomal lncRNAs are differentially expressed after spinal cord injury, suggesting that they may be involved in spinal cord injury pathology and pathogenesis. These lncRNAs could potentially serve as targets for the clinical diagnosis and treatment of spinal cord injury.

Modified insulin-like growth factor 1 containing collagen-binding domain for nerve regeneration.

Insulin-like growth factor 1 (IGF-1) is a potential nutrient for nerve repair. However, it is impractical as a therapy because of its limited half-life, rapid clearance, and limited target specificity. To achieve targeted and long-lasting treatment, we investigated the addition of a binding structure by fusing a collagen-binding domain to IGF-1. After confirming its affinity for collagen, the biological activity of this construct was examined by measuring cell proliferation after transfection into PC12 and Schwann cells using a 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay. Immunofluorescence staining was conducted to detect neurofilament and microtubule-associated protein 2 expression, while real time-polymerase chain reaction was utilized to determine IGF-1 receptor and nerve growth factor mRNA expression. Our results demonstrate a significant increase in collagen-binding activity of the recombinant protein compared with IGF-1. Moreover, the recombinant protein promoted proliferation of PC12 and Schwann cells, and increased the expression of neurofilament and microtubule-associated protein 2. Importantly, the recombinant protein also stimulated sustained expression of IGF-1 receptor and nerve growth factor mRNA for days. These results show that the recombinant protein achieved the goal of targeting and long-lasting treatment, and thus could become a clinically used factor for promoting nerve regeneration with a prolonged therapeutic effect.

Key genes expressed in different stages of spinal cord ischemia/reperfusion injury.

The temporal expression of microRNA after spinal cord ischemia/reperfusion injury is not yet fully understood. In the present study, we established a model of spinal cord ischemia in Sprague-Dawley rats by clamping the abdominal aorta for 90 minutes, before allowing reperfusion for 24 or 48 hours. A sham-operated group underwent surgery but the aorta was not clamped. The damaged spinal cord was removed for hematoxylin-eosin staining and RNA extraction. Neuronal degeneration and tissue edema were the most severe in the 24-hour reperfusion group, and milder in the 48-hour reperfusion group. RNA amplification, labeling, and hybridization were used to obtain the microRNA expression profiles of each group. Bioinformatics analysis confirmed four differentially expressed microRNAs (miR-22-3p, miR-743b-3p, miR-201-5p and miR-144-5p) and their common target genes (Tmem69 and Cxcl10). Compared with the sham group, miR-22-3p was continuously upregulated in all three ischemia groups but was highest in the group with no reperfusion, whereas miR-743b-3p, miR-201-5p and miR-144-5p were downregulated in the three ischemia groups. We have successfully identified the key genes expressed at different stages of spinal cord ischemia/reperfusion injury, which provide a reference for future investigations into the mechanism of spinal cord injury.