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This paper deals with the transnational relations of non-state armed organizations. The question is why the organizationally more successful armed groups tend to revolve around transnational networks. The hypothesis is that it has to do with the way in which they generate cohesion within their combat units. Armed groups, especially clandestine ones, tend to co-opt parochial micro-solidarity networks for the purpose of maximizing small-unit military cohesion. At the level of the wider organization, however, this entails a significant risk: societal micro-cleavages between local networks tend to create rifts within the wider organization. This is especially the case for groups that initially have no access to centralized bureaucracies able to arbitrate local struggles through anonymous rule. The paper argues that their leaders can in this context harness transnational relations to distance themselves (physically and symbolically) from these struggles, thus allowing them to arbitrate these struggles from a position of \"neutrality\". The article focuses on Lebanese Hezbollah and its transnational clerical networks. In developing the argument, it highlights that the religious nature of these clerical networks was only indirectly a source of organizational cohesion. What matters is that their long-distance character allowed weaving together previously opposed shortrange networks.

ObjectivesTo describe the incidence of acute aortic dissection in a clearly defined population, to assess onset symptoms and admission biochemical marker levels and to analyse variables potentially associated to mortality.MethodsMedical records and CT angiograms of all patients hospitalised for acute aortic dissection in the Stockholm County during the 5-year period 2012–2016 were reviewed. The patients were followed until date of death or until 31 December 2020. The annual incidence was determined. Associations between clinical and biochemical variables and 30-day mortality, respectively, were analysed using multivariable logistic regression models.ResultsA total of 344 patients were included. The mean annual incidence of acute aortic dissection was 4.1 per 100 000. Median age was 67 years (range 24–91) and 34% (n=118) were women. Type A dissection was predominant; 220 patients (64%) had type A and 124 (36%) had type B. Painless dissection was more common in type A than in type B (18% vs 15%, p=0.003). Type A dissection patients also more commonly had elevated plasma troponin T (44% vs 21%, p<0.001) and thrombocytopenia (26% vs 15%, p=0.010) than type B dissection patients on admission. Overall, 30-day mortality was 28% in type A and 11% in type B (p<0.001). Both painless dissection (OR 4.30, 95% CI 1.80 to 10.28, p=0.001) and elevated troponin T (OR 3.78, 95% CI 2.01 to 7.12, p<0.001), respectively, were associated with increased 30-day mortality in all acute aortic dissection patients. Thrombocytopenia was associated with elevated 30-day mortality only in patients with type A (OR 3.09, 95% CI 1.53 to 6.21, p=0.002).ConclusionsNearly two-thirds of acute aortic dissection patients had type A. Levels of troponin T and platelets, respectively, paired with presence or absence of typical symptoms may become useful adjuncts in risk stratification of patients with acute aortic dissection.

ObjectivesThe objective of this study was to develop clinical classifiers aiming to identify prevalent ascending aortic dilatation in patients with bicuspid aortic valve (BAV) and tricuspid aortic valve (TAV).Design and settingA prospective, single-centre and observational cohort.ParticipantsThe study involved 543 BAV and 491 TAV patients with aortic valve disease and/or ascending aortic dilatation, excluding those with coronary artery disease, undergoing cardiothoracic surgery at the Karolinska University Hospital (Sweden).Main outcome measuresPredictors of high risk of ascending aortic dilatation (defined as ascending aorta with a diameter above 40 mm) were identified through the application of machine learning algorithms and classic logistic regression models.ExposuresComprehensive multidimensional data, including valve morphology, clinical information, family history of cardiovascular diseases, prevalent diseases, demographic details, lifestyle factors, and medication.ResultsBAV patients, with an average age of 60.4±12.4 years, showed a higher frequency of aortic dilatation (45.3%) compared with TAV patients, who had an average age of 70.4±9.1 years (28.9% dilatation, p <0.001). Aneurysm prediction models for TAV patients exhibited mean area under the receiver-operating-characteristic curve (AUC) values above 0.8, with the absence of aortic stenosis being the primary predictor, followed by diabetes and high-sensitivity C reactive protein. Conversely, prediction models for BAV patients resulted in AUC values between 0.5 and 0.55, indicating low usefulness for predicting aortic dilatation. Classification results remained consistent across all machine learning algorithms and classic logistic regression models.Conclusion and recommendationCardiovascular risk profiles appear to be more predictive of aortopathy in TAV patients than in patients with BAV. This adds evidence to the fact that BAV-associated and TAV-associated aortopathy involves different pathways to aneurysm formation and highlights the need for specific aneurysm preventions in these patients. Further, our results highlight that machine learning approaches do not outperform classical prediction methods in addressing complex interactions and non-linear relations between variables.

Previous studies have demonstrated that environmental and temporal factors may affect the incidence of acute type A aortic dissection (ATAAD). Here, we aimed to investigate the hypothesis that national holidays and weekends influence the incidence of surgery for ATAAD. For the period 1st of January 2005 until 31st of December 2019, we investigated a hypothesised effect of (country-specific) national holidays and weekends on the frequency of 2995 surgical repairs for ATAAD at 10 Nordic cities included in the Nordic Consortium for Acute Type A Aortic Dissection (NORCAAD) collaboration. Compared to other days, the number of ATAAD repairs were 29% (RR 0.71; 95% CI 0.54–0.94) lower on national holidays and 26% (RR 0.74; 95% CI 0.68–0.82) lower on weekends. As day of week patterns of symptom duration were assessed and the primary analyses were adjusted for period of year, our findings suggest that the reduced surgical incidence on national holidays and weekends does not seem to correspond to seasonal effects or surgery being delayed and performed on regular working days.

We evaluated the association between cardiopulmonary bypass (CPB) time during surgery for acute type A aortic dissection (ATAAD) and mid-term survival. Data of 1122 patients who underwent surgery for ATAAD in eight Nordic centers from January 2005 to December 2014 were retrospectively analyzed. An adjusted logistic regression analysis was performed to investigate the association of incremental 30 min CPB time on 30-day mortality. In addition, the patients were divided into those that underwent surgery with >210 min (n = 369) or <210 min CPB time (n = 605) based on spline analysis and a receiver operating characteristic curve. The restricted mean survival time ratios adjusted for patient characteristics and surgical details between the groups were calculated for survival and aortic reoperation-free survival. The median follow-up time was 2.6 (inter-quartile range 0.9–4.9) years. Incremental CPB time was associated with higher 30-day mortality (OR 1.25 per 30 min, 95% CI 1.15–1.35, p < 0.001). Mid-term survival for all patients was inferior in the >210 min group as compared with the <210 min group (adjusted restricted mean survival time ratio 0.88, 95% confidence interval [CI] 0.81–0.96, p = 0.003). Reoperation-free survival was similar in patients with CPB time > 210 min as compared with <210 min. Prolonged CPB time is associated with higher 30-day mortality and inferior mid-term survival but not with inferior reoperation-free survival after surgical repair of ATAAD.

ObjectiveDetermine whether associations between bicuspid aortic valve (BAV) phenotypes, valve disease and aortopathy differ between sexes.Methods1045 patients with BAV (76.0% men, n=794) from two surgical centres were included in this cross-sectional study. Valve phenotype was classified intraoperatively as right–left (RL), right-non-coronary (RN), left-non-coronary (LN) or 2-sinus BAV. Echocardiography was used to determine type and degree of valve disease, and aortic dimensions. Aortic dilatation was defined as diameter ≥4.5 cm.ResultsRL was the most common phenotype (73.6%), followed by RN (16.2%), 2-sinus BAV (9.2%) and LN (1.1%), with no difference in phenotype distribution between men and women (p=0.634). Aortic valve insufficiency (AI) prevalence differed significantly with valve phenotype in men (p=0.047), with RL and LN having the highest prevalence (34.1% and 44.0%, respectively). In women, RN had a higher proportion of AI than RL (21.3% vs 7.3%, p=0.017). Men with RL had larger root dimensions, in particular at the sinus (mean difference 0.24 cm compared with RN, p=0.002). Men with 2-sinus BAV had the highest prevalence of root phenotype dilatation (7.0%, other phenotypes ≤2.3%, p=0.031), whereas women with 2-sinus BAV did not have root dilatation and smaller sinus dimensions (mean difference: 0.35 cm compared with RL, p=0.021). Aortic root segments were larger in men with AI compared with aortic stenosis (sinus mean difference: 0.40 cm, p<0.001). The difference was even larger in women (mean difference: 0.78 cm, p<0.001), and women with AI also had larger tubular segments (mean difference: 0.61 cm, p=0.001).ConclusionsThere are significant sex differences in clinical associations of BAV phenotypes, which should be considered in further studies on the role of phenotypes in individualised patient management.

We aimed to investigate a hypothesised association between daily mean temperature and the risk of surgery for acute type A aortic dissection (ATAAD). For the period of 1 January 2005 until 31 December 2019, we collected daily data on mean temperatures and date of 2995 operations for ATAAD at 10 Nordic cities included in the Nordic Consortium for Acute Type A Aortic Dissection (NORCAAD) collaboration. Using a two-stage time-series approach, we investigated the association between hot and cold temperatures relative to the optimal temperature and the rate of ATAAD repair in the selected cities. The relative risks (RRs) of cold temperatures (≤−5°C) and hot temperatures (≥21°C) compared to optimal temperature were 1.47 (95% CI: 0.72-2.99) and 1.43 (95% CI: 0.67-3.08), respectively. In line with previous studies, we observed increased risk at cold and hot temperatures. However, the observed associations were not statistically significant, thus only providing weak evidence of an association.

Background Diabetes is a risk factor for peripheral, coronary, and cerebrovascular disease. In contrast, results also indicate that patients with diabetes have reduced prevalence of aortic aneurysms, although the mechanisms remain largely unknown. We hypothesize that altered endogenous secretion of the intestinal hormone glucagon-like peptide-1 (GLP-1)—previously shown to protect from aneurysm formation, and governing many of the mechanisms thought to be involved in aneurysm formation—may provide insights into the mechanisms underlying the inverse relationship of diabetes and aneurysm. Methods We undertook a case–control study to characterize circulating plasma GLP-1 levels in diabetic and non-diabetic surgical patients with aortic valve disease, and with or without ascending aortic dilation. The cohort included patients with a bicuspid aortic valve (BAV), a common congenital disorder associated with ascending aortic aneurysm, as well as patients with a tricuspid aortic valve (TAV). Results In our patient group, diabetes was characterized by a significant increase in fasting plasma GLP-1 levels. Further, we show that aortic dilation in these patients was associated with a significant increase in fasting plasma GLP-1, although a significant increase in the intact and bioactive peptide could not be detected in BAV patients with aortic dilation. Conclusion A subgroup of diabetic patients with aortic valve pathology have increased fasting plasma GLP-1 levels, which may be of importance for the low prevalence of aortic dilation in this patient group. Further, in TAV patients, GLP-1 secretion and plasma levels of intact GLP-1 are upregulated in association with aortic dilation, possibly indicating a compensatory mechanism.

Glucagon-like peptide-1 (GLP-1) regulates processes involved in the pathophysiology of thoracic aortic aneurysms (TAAs), including inflammation, while protecting against aortic aneurysms in animal models. Type 2 diabetes (T2D) involves altered GLP-1 signaling due to pathology and/or therapy and is associated with reduced prevalence of TAAs. We aimed to assess whether T2D alters the inflammatory profile/proteolytic activity, possible correlations to elevated fasting GLP-1 (F-GLP-1), and its relevance for TAA. F-GLP-1, pro-inflammatory T helper 1 (Th1) cytokines, Th2 cytokines, C-reactive protein, and matrix metalloproteinase-2 activity (MMP-2) were analyzed in surgical patients with aortic valve pathology with/without T2D and without T2D but with TAA. Patients with T2D displayed an increase in the relative systemic expression of interleukin 6 and tumor necrosis factor α and a clear trend towards reduced levels of interferon γ (IFNγ). In addition, a positive association between GLP-1 and the plasma interleukin 4 (IL-4)/IFNγ ratio was detected. TAA was associated with significantly lower plasma levels of the Th2 cytokines IL-4 and interleukin 5. Plasma MMP-2 activity did not differ between groups. We conclude that T2D involved a Th2 shift, which associates with elevated F-GLP-1 and may—considering Th1 bias in TAA—contribute to reduced prevalence of TAA in T2D.