CT angiography and CT perfusion improve prediction of infarct volume in patients with anterior circulation stroke

Introduction: We investigated whether baseline CT angiography (CTA) and CT perfusion (CTP) in acute ischemic stroke could improve prediction of infarct presence and infarct volume on follow-up imaging. Methods: We analyzed 906 patients with suspected anterior circulation stroke from the prospective multicenter Dutch acute stroke study (DUST). All patients underwent baseline non-contrast CT, CTA, and CTP and follow-up non-contrast CT/MRI after 3 days. Multivariable regression models were developed including patient characteristics and non-contrast CT, and subsequently, CTA and CTP measures were added. The increase in area under the curve (AUC) and R2 was assessed to determine the additional value of CTA and CTP. Results: At follow-up, 612 patients (67.5 %) had a detectable infarct on CT/MRI; median infarct volume was 14.8 mL (interquartile range (IQR) 2.8–69.6). Regarding infarct presence, the AUC of 0.82 (95 % confidence interval (CI) 0.79–0.85) for patient characteristics and non-contrast CT was improved with addition of CTA measures (AUC 0.85 (95 % CI 0.82–0.87); p < 0.001) and was even higher after addition of CTP measures (AUC 0.89 (95 % CI 0.87–0.91); p < 0.001) and combined CTA/CTP measures (AUC 0.89 (95 % CI 0.87–0.91); p < 0.001). For infarct volume, adding combined CTA/CTP measures (R2 = 0.58) was superior to patient characteristics and non-contrast CT alone (R2 = 0.44) and to addition of CTA alone (R2 = 0.55) or CTP alone (R2 = 0.54; all p < 0.001). Conclusion: In the acute stage, CTA and CTP have additional value over patient characteristics and non-contrast CT for predicting infarct presence and infarct volume on follow-up imaging. These findings could be applied for patient selection in future trials on ischemic stroke treatment

Risk factors for atherosclerotic and medial arterial calcification of the intracranial internal carotid artery

_Background and aims:_ Calcifications of the intracranial internal carotid artery (iICA) are an important risk factor for stroke. The calcifications can occur both in the intimal and medial layer of the vascular wall. The aim of this study is to assess whether medial calcification in the iICA is differently related to risk factors for cardiovascular disease, compared to intimal calcification. _Methods:_ Unenhanced thin slice computed tomography (CT) scans from 1132 patients from the Dutch acute stroke study cohort were assessed for dominant localization of calcification (medial or intimal) by one of three observers based on established methodology. Associations between known cardiovascular risk factors (age, gender, body mass index, pulse pressure, eGFR, smoking, hypertension, diabetes mellitus, hyperlipidemia, previous vascular disease, and family history) and the dominant localization of calcifications were assessed via logistic regression analysis. _Results:_ In the 1132 patients (57% males, mean age 67.4 years [SD 13.8]), dominant intimal calcification was present in 30.9% and dominant medial calcification in 46.9%. In 10.5%, no calcification was seen. Age, pulse pressure and family history were risk factors for both types of calcification. Multivariably adjusted risk factors for dominant intimal calcification only were smoking (OR 2.09 [CI 1.27–3.44]) and hypertension (OR 2.09 [CI 1.29–3.40]) and for dominant medial calcification diabetes mellitus (OR 2.39 [CI 1.11–5.14]) and previous vascular disease (OR 2.20 [CI 1.30–3.75]). _Conclusions:_ Risk factors are differently related to the dominant localizations of calcifications, a finding that supports the hypothesis that the intimal and medial calcification represents a distinct etiology

No relation between body temperature and arterial recanalization at three days in patients with acute ischaemic stroke

Background: Recanalization of an occluded intracranial artery is influenced by temperature-dependent enzymes, including alteplase. We assessed the relation between body temperature on admission and recanalization. Methods: We included 278 patients with acute ischaemic stroke within nine hours after symptom onset, who had an intracranial arterial occlusion on admission CT angiography, in 13 participating centres. We calculated the relation per every 0.1°Celsius increase in admission body temperature and recanalization at three days. Results: Recanalization occurred in 80% of occluded arteries. There was no relation between body temperature and recanalization at three days after adjustments for age, NIHSS score on admission and treatment with alteplase (adjusted odds ratio per 0.1°Celsius, 0.99; 95% confidence interval, 0.94-1.05; p = 0.70). Results for patients treated or not treated with alteplase were essentially the same. Conclusions: Our findings suggest that in patients with acute ischaemic stroke there is no relation between body temperature on admission and recanalization of an occluded intracranial artery three days later, irrespective of treatment with alteplase

Temporal profile of body temperature in acute ischemic stroke: Relation to infarct size and outcome

Background: High body temperatures after ischemic stroke have been associated with larger infarct size, but the temporal profile of this relation is unknown. We assess the relation between temporal profile of body temperature and infarct size and functional outcome in patients with acute ischemic stroke. Methods: In 419 patients with acute ischemic stroke we assessed the relation between body temperature on admission and during the first 3 days with both infarct size and functional outcome. Infarct size was measured in milliliters on CT or MRI after 3 days. Poor functional outcome was defined as a modified Rankin Scale score ≥3 at 3 months. Results: Body temperature on admission was not associated with infarct size or poor outcome in adjusted analyses. By contrast, each additional 1.0 °C in body temperature on day 1 was associated with 0.31 ml larger infarct size (95% confidence interval (CI) 0.04-0.59), on day 2 with 1.13 ml larger infarct size(95% CI, 0.83-1.43), and on day 3 with 0.80 ml larger infarct size (95% CI, 0.48-1.12), in adjusted linear regression analyses. Higher peak body temperatures on days two and three were also associated with poor outcome (adjusted relative risks per additional 1.0 °C in body temperature, 1.52 (95% CI, 1.17-1.99) and 1.47 (95% CI, 1.22-1.77), respectively). Conclusions: Higher peak body temperatures during the first days after ischemic stroke, rather than on admission, are associated with larger infarct size and poor functional outcome. This suggests that prevention of high temperatures may improve outcome if continued for at least 3 days

Fine sediment in mixed sand-silt environments impact bedform geometry by altering sediment mobility

Geometric characteristics of subaqueous bedforms, such as height, length and leeside angle, are crucial for determining hydraulic form roughness and interpreting sedimentary records. Traditionally, bedform existence and geometry predictors are primarily based on uniform, cohesionless sediments. However, mixtures of sand, silt and clay are common in deltaic, estuarine, and lowland river environments, where bedforms are ubiquitous. Therefore, we investigate the impact of fine sand and silt in sand-silt mixtures on bedform geometry, based on laboratory experiments conducted in a recirculating flume.We systematically varied the fraction of sand and silt for different discharges, and utlized an acoustic Doppler velocimeter to measure flow velocity profiles. The final bed geometry was captured using a line laser scanner. Our findings reveal that the response of bedforms to an altered fine sediment percentage is ambiguous, and likely depends on, among others, bimodality-driven bed mobility and sediment cohesiveness. When fine, non-cohesive material (fine sand or coarse silt) is mixed with the base material (medium sand), an increased dune height and length is observed, possibly caused by the hiding exposure effect, resulting in enhanced mobility of the coarser material. However, weakly cohesive fine silt suppresses dune height and length, possibly caused by reduced sedimentmobility. Finally, in the transition from dunes to upper stage plane bed, there are indications that the bed becomes unstable and dune heights vary over time. The composition of the bed material does not significantly impact the hydraulic roughness, but mainly affects roughness via the bed morphology, especially the leeside angle

TRACKing or TRUSTing transfusion prediction:Validation of Red blood cell transfusion prediction models for low transfusion rate cardiac surgery and high transfusion rate post-cardiotomy veno-arterial extracorporeal life support

Abstract bodyPreoperative identification of patients at risk of red blood cell (RBC) transfusion is necessary to prevent adverse outcomes. Several models can determine this risk. Models like TRACK, TRUST and ACTA-PORT differ in complexity and performance. Some models outperform TRACK, but their complexity limits clinical application. In 2009, the TRACK model was developed with criteria for everyday practice, simplicity and easy clinical implementation. Advances in hemodilution management in Europe has reduced transfusion rates in adult cardiac surgery, necessitating re-evaluation of the TRACK model in low transfusion rate populations.MethodsThe TRACK model was validated using 4053 adult patients who underwent cardiac surgery between 2015 and 2022. Subsequently, the database was divided at random into a derivation and validation data set. Original coefficients of the TRACK model were updated in the derivation data set and validated in a validation data set on accuracy and discriminative ability. Model calibration and discriminative ability were assessed as measures of model performance. Further, the TRACK model will be validated and updated in the same way for predicting blood transfusion in post-cardiotomy ECLS patients.ResultsAll variables but age remained significant in the external validation of the TRACK model. The odds ratio of female sex on blood transfusion increased from 1.42 to 2.42 (95% CI, 1.94 – 3.02). The original TRACK model demonstrated an area under the curve (AUC) of 0.76 (95% CI, 0.74 – 0.78) while showing poor calibration indicating overoptimistic estimation of RBC transfusion risk (p &lt; 0.05). The updated TRACK model demonstrated a slightly higher AUC of 0.78 (95% CI,0.75 – 0.81) and showed good calibration over all risk strata (p = 0.19).ConclusionsRefining the TRACK coefficients improved preoperative at-risk identification. The updated TRACK model improves predicted accuracy and may help clinicians make better discissions, especially in low-transfusion adult cardiac surgery. This study demonstrates the feasibility of RBC transfusion prediction models for adult cardiac surgery. Our ongoing study is evaluating RBC transfusion prediction models for post-cardiotomy ECLS. These results will also be presented at the conference.<br/

Delirium risk screening and haloperidol prophylaxis program in hip fracture patients is a helpful tool in identifying high-risk patients, but does not reduce the incidence of delirium

Background: Delirium in patients with hip fractures lead to higher morbidity and mortality. Prevention in high-risk patients by prescribing low dose haloperidol is currently under investigation. Methods. This prospective cohort surveillance assessed hip fracture patients for risk of developing a delirium with the Risk Model for Delirium (RD) score. High-risk patients (score ≥5 points) were treated with a prophylactic low-dose of haloperidol according to hospital protocol. Primary outcome was delirium incidence. Secondary outcomes were differences between high- and low-risk patients in delirium, length of stay (LOS), return to pre-fracture living situation and mortality. Logistic regression analysis was performed with age, ASA-classification, known dementia, having a partner, type of fracture, institutional residence and psychotropic drug use as possible confounders. Results: 445 hip fracture patients aged 65 years and older were admitted from January 2008 to December 2009. The RD-score was completed in 378 patients, 173 (45.8%) high-risk patients were treated with prophylactic medication. Sensitivity was 71.6%, specificity 63.8% and the negative predictive value (NPV) of a score < 5 was 85.9%. Delirium incidence (27.0%) was not significantly different compared to 2007 (27.8%) 2006 (23.9%) and 2005 (29.0%) prior to implementation of the RD- protocol. Logistic regression analysis showed that high-risk patients did have a significant higher delirium incidence (42.2% vs. 14.1%, OR 4.1, CI 2.43-7.02). They were more likely to be residing at an alternative living situation after 3 months (62.3% vs. 17.0%, OR 6.57, CI 3.23-13.37) and less likely to be discharged from hospital before 10 days (34.9% vs. 55.9%, OR 1.63, CI 1.03-2.59). Significant independent risk factors for a delirium were a RD-score 5 (OR 4.13, CI 2.43-7.02), male gender (OR 1.93, CI 0.99-1.07) and age (OR 1.03, CI 0.99-1.07). Conclusions: Introducing the delirium prevention protocol did not reduce delirium incidence. The RD-score did identify patients with a high risk to develop a delirium. This high-risk group had a longer LOS and returned to pre-fracture living situation less often. The NPV of a score < 5 was high, as it should be for a screening instrument. Concluding, the RD-score is a useful tool to identify patients with poorer outcome

Social media and sensemaking patterns in new product development: demystifying the customer sentiment

Artificial intelligence by principle is developed to assist but also support decision making processes. In our study, we explore how information retrieved from social media can assist decision-making processes for new product development (NPD). We focus on consumers’ emotions that are expressed through social media and analyse the variations of their sentiments in all the stages of NPD. We collect data from Twitter that reveal consumers’ appreciation of aspects of the design of a newly launched model of an innovative automotive company. We adopt the sensemaking approach coupled with the use of fuzzy logic for text mining. This combinatory methodological approach enables us to retrieve consensus from the data and to explore the variations of sentiments of the customers about the product and define the polarity of these emotions for each of the NPD stages. The analysis identifies sensemaking patterns in Twitter data and explains the NPD process and the associated steps where the social interactions from customers can have an iterative role. We conclude the paper by outlining an agenda for future research in the NPD process and the role of the customer opinion through sensemaking mechanisms