Search

Myocardial infarction without obstructive coronary artery (MINOCA) refers to myocardial infarction (MI) that occurs when the lumen area of coronary artery stenosis is ≤50%, accounting for 1% to 14% of the total MI. The etio-logy of MINOCA is complex and diverse, and accurate diagnosis and identification of the potential causes of MINOCA are crucial for guiding subsequent clinical management. Based on the unique advantages of myocardial tissue imaging, non-invasive cardiac magnetic resonance (CMR) examination has been widely recognized for its value in the management of MINOCA patients. CMR can be used to exclude diseases similar to MI, such as myocarditis and stress-induced cardio-myopathy, and identify the potential causes of MINOCA. It is a necessary diagnostic tool in the diagnostic process, helping to reduce overdiagnosis, misdiagnosis, and missed diagnosis of true MINOCA. Currently, it has been recommended by the American Heart Association (AHA) and the European Society of Cardiology (ESC) as an essential examination method in the MINOCA management process. In addition, compared with patients with coronary artery occlusion, MINOCA patients have a better short-term prognosis, but the risk of poor prognosis increases in long-term follow-up. It is necessary to pay more attention to the prognosis and risk stratification of MINOCA patients and management process. The traditional MI prognosis evaluation system is not entirely applicable to MINOCA patients, and CMR can provide valuable information for the prognosis evaluation of MINOCA patients. Currently, there are no standardized norms or guidelines for the application of CMR in the management of MINOCA patients in China. This article aims to review the application norms and prognostic value of CMR technology in clinical management of MINOCA, providing reference for clinical practice and enhancing understanding and management of this special MI lesion.

Self‐protective carbonized polymer dots (CPDs) with advantageous crosslinked nano‐structures have attracted considerable attention in metal‐free room temperature phosphorescence (RTP) materials, whereas their RTP emissions are still limited to short wavelength. Expanding their RTP emissions to Near‐Infrared (NIR) range is attractive but suffers from the difficulties in constructing narrow energy levels and inhibiting intense non‐radiative decay. Herein, a crosslink‐enhanced emission (CEE)‐dominated construction strategy was proposed, achieving desired NIR RTP (710 nm) in self‐protective CPDs for the first time. Structural factors, i.e. crosslinking (covalent‐bond CEE), conjugation (conjugated amine with bridging N−H and C=C group), and steric hindrance (confined‐domain CEE), were confirmed indispensable for triggering NIR RTP emission in CPDs. Contrast experiments and theoretical calculations further revealed the rationality of the design strategy originating from CEE in terms of promoting the narrow energy level emission of triplet excitons and inhibiting the non‐radiative quenching. This work not only firstly achieves NIR RTP in self‐protective CPDs but also helps understand the origin of NIR RTP to further guide the synthesis of diverse CPDs with efficient long‐wavelength RTP emission. [ABSTRACT FROM AUTHOR]

Current tunnel blasting hole layouts are mostly designed based on a two-dimensional plane at the workface, without considering the distribution of the minimum burden at the bottom of the blast holes. This results in a significant number of residual holes at the bottom, reducing excavation efficiency. To address this issue, this study proposes an easer hole design method based on the principle of minimum burden at the hole bottom. The method involved the arithmetic distribution for the minimum burden at the bottom of easer holes, using the difficulty of rock breaking as the design principle for hole positioning. Through theoretical analysis, numerical simulation, and field tests, it is proposed that the minimum burden at the bottom of the holes should increase progressively with the initiation sequence, and the relationship between burden distribution and blasting effect was investigated. This study indicates that using the new design principle achieves better blasting results than the model with an evenly distributed burden. When the control ratio of the minimum burden at the bottom of each row of easer holes is 1.3, an average residual hole depth of 36.7 cm and a maximum damage volume of 4.638 m3 can be achieved, yielding the best overall blasting effect. The application of this blasting scheme in the field significantly improved the residual hole problem, reducing the average residual hole depth to 39.5 cm, which is a 43.4% reduction compared to the previous scheme. Additionally, the utilization rate of blast holes in the new scheme increased to 91.3%, an improvement of 11.0% over the previous scheme. This study provides new insights and methods for tunnel blasting hole layout design, offering significant engineering application value. [ABSTRACT FROM AUTHOR]

Background: Sudden cardiac death (SCD) after myocardial infarction (MI) is mostly caused by ventricular arrhythmias. As an arrhythmogenic substrate, infarct border zone (BZ) results in adverse electrophysiological properties. Purpose: To explore myocardial scar entropy (BZ, infarct core [IC], BZ + IC, expressed as IBZ) and to investigate their prognostic value combined with left ventricular (LV) strain parameters (global radial strain [GRS], global circumferential strain [GCS], global longitudinal strain [GLS]) in patients after MI. Study Type: Prospective. Population: One hundred fifty‐seven patients with previous MI, 26 in primary endpoint events group, 30 in secondary endpoint events group, and 43 in total endpoint events (primary + secondary). Field Strength/Sequence: 3.0 T/cine, late gadolinium enhancement (LGE). Assessment: Three‐dimensional feature tracking analysis for three directions (radial, circumferential, and longitudinal), entropy and extent of infarct‐related areas (BZ, IC, and IBZ), LV functional parameters. Statistical Tests: Student t‐test, Mann–Whitney U, Spearman or Pearson rank correlation analysis, receiver operating characteristic curve, Kaplan–Meier event‐free survival curve, and Cox proportional hazards regression were used. Results were considered statistically significant at P < 0.05. Results: LGE extent and entropy of all infarct‐related areas (BZ, IC, and IBZ) were significantly higher and GLS were lower in patients with endpoint events than those without. BZ and IBC entropy were further associated with LV strain in after‐MI patients. In the univariable and multivariable Cox analysis, BZ entropy manifested independent association with primary endpoint events (hazard ratio: 3.859; 95% confidence interval: 2.136–6.974). Primary and secondary endpoint events prognostic value was improved by the addition of BZ entropy and GLS to the LVEF model (Delong test, Z = 2.729 for primary endpoint events; Z = 3.230 for secondary endpoint events). Data Conclusion: Entropy of myocardial fibrosis was associated with LV strain. Assessment of BZ entropy and GLS improved prognostic value for endpoint events of LVEF. Level of Evidence: 1 Technical Efficacy: Stage 5 [ABSTRACT FROM AUTHOR]

Objectives: Atherosclerosis is a common vascular disease. MiR-637 has been demonstrated to be low-expressed in hypertensive patients, and atherosclerosis is closely related to hypertension. Therefore, this study speculated that miR-637 may play an important role in the development of atherosclerosis. In brief, this study examined the expression level of miR-637 in patients with atherosclerosis and further analyzed its clinical value in patients with atherosclerosis. Methods: The expression level of miR-637 was detected in serum from 86 patients with atherosclerosis and 75 healthy controls by using quantitative reverse transcription-polymerase chain reaction. The receiver operating characteristic curve was used to assess the diagnostic value of miR-637 in atherosclerosis. Pearson's correlation analysis was performed to evaluate the relationship between serum miR-637 and different clinical parameters. The prognostic value of miR-637 in atherosclerosis was analyzed by the Kaplan–Meier survival curve and multivariate cox regression analysis. Results: Compared with healthy individuals, miR-637 was downregulated in the serum of atherosclerosis patients. The receiver operating characteristic curve suggested the high diagnostic value of miR-637 for atherosclerosis, with the AUC of 0.853, specificity of 77.9%, and sensitivity of 80.0%. The expression level of miR-637 was negatively correlated with CIMT (r = –0.8101, P < 0.0001) and CRP (r = –0.6154, P < 0.0001), respectively. Survival analysis indicated that miR-637 was also found to be an independent prognostic factor for atherosclerosis. Conclusions: MiR-637 is a potential noninvasive diagnostic marker of atherosclerosis and has important predictive value for the occurrence of future cardiovascular events. [ABSTRACT FROM AUTHOR]

Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://qims.amegroups.com/article/view/10.21037/qims-21-834/coif). The authors have no conflicts of interest to declare.