Heart-brain connections in vascular cognitive impairment: The contribution of cardiovascular factors along the heart-brain axis to Vascular Cognitive Impairment

As people age, health issues like cardiovascular diseases, memory problems, and dementia become more common. These conditions are closely linked along the ‘heart-brain axis’. Cognitive impairments include problems with memory, language, math, information processing, attention, concentration, planning, and decision-making. Dementia involves severe impairments that hinder daily activities, while mild cognitive impairment has less severe effects. Vascular Cognitive Impairment (VCI) encompasses all cognitive issues related to vascular brain damage, from subjective memory decline to dementia. Vascular damage, including strokes and cerebral small vessel disease, contributes to VCI. Disrupted cerebral blood flow, influenced by factors like heart function, blood pressure, and vessel stiffness, also may play a key role. This thesis aimed to study cardiovascular factors along the heart-brain axis contributing to VCI. It focused on: 1. Identifying heart failure patients at risk for VCI: VCI is common in heart failure patients, but identifying those at risk is challenging with routine patient characteristics. 2. Exploring the role of sex and hemoglobin in VCI: Men and women show different patterns of brain vascular injury and cognitive functioning. Lower hemoglobin levels are linked to worse cognitive performance in patients with carotid artery occlusion. 3. Investigating biological processes underlying VCI: Clusters of blood-based cardiovascular biomarkers related to coagulation, extracellular matrix organization, inflammation, angiogenesis, and signal transduction appear to be involved in VCI. The findings in this thesis contribute to a better understanding of VCI. If future research can confirm the results of this thesis, the findings could be used for (sex-specific) prevention and treatment of patients with VCI

Views of patients with multi-morbidity on what is important for patient-centered care in the primary care setting

__Background:__ Patient-centered care (PCC) has been proposed as the way forward in improving primary care for patients with multi-morbidity. However, it is not clear what PCC exactly looks like in practice for patients with multimorbidity. A better understanding of multi-morbid patients’ views on what PCC should look like and which elements are most important may help to improve care delivery for this vulnerable population. The present study thus aimed to identify views of patients with multi-morbidity on the relative importance of PCC aspects in a Dutch primary care setting. __Methods:__ Interviews were conducted with 16 patients with multi-morbidity using Q-methodology, which combines quantitative and qualitative analyses. The participants ranked 28 statements about the eight dimensions of PCC (patients’ preferences, information and education, access to care, emotional support, family and friends, continuity and transition, physical comfort, and coordination of care) by relative importance. By-person factor analysis using centroid factor extraction and varimax rotation were used to reveal factors that represent viewpoints. Qualitative interview data were used to interpret the viewpoints. __Results:__ The analyses revealed three factors representing three distinct viewpoints of patients with multi-morbidity on what is important for patient-centered care in the primary care setting. Patients with viewpoint 1 are prepared proactive patients who seem to be well-off and want to be in charge of their own care. To do so, they seek medical information and prefer to be supported by a strongly coordinated multidisciplinary team of healthcare professionals. Patients with viewpoint 2 are everyday patients who visit GPs and require well-coordinated, respectful, and supportive care. Patients with viewpoint 3 are vulnerable patients who are less resourceful in terms of communication skills and finances, and thus require accessible care and professionals taking the lead while treating them with dignity and respect. __Conclusion:__ The findings of this study suggest that not all patients with multi-morbidity require the same type of care delivery, and that not all aspects of PCC delivery are equally important to all patients

The Need for Co-Creation of Care with Multi-Morbidity Patients

__Background:__ Primary care delivery for multimorbid patients is complex, due to single disease–oriented guidelines, complex care needs, time constraints and the involvement of multiple healthcare professionals. Co-creation of care, based on the quality of communication and relationships between healthcare professionals and patients, may therefore be valuable. This longitudinal study investigates the relationships of co-creation of care to physical and social well-being and satisfaction with care among multimorbid patients in primary care. __Methods:__ In 2017 and 2018, longitudinal surveys were conducted among multimorbid patients from seven primary care practices in Noord-Brabant, the Netherlands. Paired sample t-tests and multivariate regression analyses were performed. __Results:__ Co-creation of care improved significantly over time, as did social well-being and physical well-being but not satisfaction with care. Improvements in co-creation of care from T0 to T1 were associated with social well-being, physical well-being and satisfaction with care. __Conclusions:__ Thus, investment in co-creation of care by primary care practices may lead to better outcomes for multimorbid patients

Remote sensing of surface melt on Antarctica: opportunities and challenges

Surface melt is an important driver of ice shelf disintegration and its consequent mass loss over the Antarctic Ice Sheet. Monitoring surface melt using satellite remote sensing can enhance our understanding of ice shelf stability. However, the sensors do not measure the actual physical process of surface melt, but rather observe the presence of liquid water. Moreover, the sensor observations are influenced by the sensor characteristics and surface properties. Therefore, large inconsistencies can exist in the derived melt estimates from different sensors. In this study, we apply state-of-the-art melt detection algorithms to four frequently used remote sensing sensors, i.e., two active microwave sensors, which are Advanced Scatterometer (ASCAT) and Sentinel-1, a passive microwave sensor, i.e., Special Sensor Microwave Imager/Sounder (SSMIS), and an optical sensor, i.e., Moderate Resolution Imaging Spectroradiometer (MODIS). We intercompare the melt detection results over the entire Antarctic Ice Sheet and four selected study regions for the melt seasons 2015-2020. Our results show large spatiotemporal differences in detected melt between the sensors, with particular disagreement in blue ice areas, in aquifer regions, and during wintertime surface melt. We discuss that discrepancies between sensors are mainly due to cloud obstruction and polar darkness, frequency-dependent penetration of satellite signals, temporal resolution, and spatial resolution, as well as the applied melt detection methods. Nevertheless, we argue that different sensors can complement each other, enabling improved detection of surface melt over the Antarctic Ice Sheet

Firn air content changes on Antarctic ice shelves under three future warming scenarios

The Antarctic firn layer provides pore space in which an estimated 94% to 96% of the surface melt refreezes or is retained as liquid water. Future depletion of firn pore space by increased surface melt, densification and formation of low-permeability ice slabs can potentially lead to meltwater ponding, hydrofracturing and ice-shelf disintegration. Here, we investigate the 21st-century evolution of total firn air content (FAC) and accessible FAC (i.e. the pore space that meltwater can reach) across Antarctic ice shelves. We use the semi-empirical IMAU Firn Densification Model (IMAU-FDM) with an updated dynamical densification expression to cope with changing climate forcing. The firn model is forced by general circulation model output of the Community Earth System Model version 2 (CESM2) for three climate emission scenarios (SSP1-2.6, SSP2-4.5 and SSP5-8.5), dynamically downscaled to a 27km horizontal resolution by the Regional Atmospheric Climate Model version 2.3p2 (RACMO2.3p2). To estimate accessible FAC, we prescribe a relationship between ice-slab thickness and permeability. In our simulations, ice shelves on the Antarctic Peninsula and the Roi Baudouin Ice Shelf in Dronning Maud Land are particularly vulnerable to total FAC depletion (>50% decrease by 2100), even for low-emission (SSP1-2.6) and intermediate-emission (SSP2-4.5) scenarios. In the high-emission (SSP5-8.5) scenario in particular, the formation of ice slabs further reduces accessible FAC on ice shelves with low accumulation rates (current rates of <500mmw.e.yr-1), including many East Antarctic ice shelves and the Filchner-Ronne, Ross, Pine Island and Larsen C ice shelves. These results underline the potentially large vulnerability of low-accumulation ice shelves to firn air depletion through ice-slab formation

Characteristics of the 1979–2020 Antarctic firn layer simulated with IMAU-FDM v1.2A

Firn simulations are essential for understanding Antarctic ice sheet mass change, as they enable us to convert satellite altimetry observed volume changes to mass changes and column thickness to ice thickness and to quantify the meltwater buffering capacity of firn. Here, we present and evaluate a simulation of the contemporary Antarctic firn layer using the updated semi-empirical IMAU Firn Densification Model (IMAU-FDM) for the period 1979–2020. We have improved previous fresh-snow density and firn compaction parameterizations and used updated atmospheric forcing. In addition, the model has been calibrated and evaluated using 112 firn core density observations across the ice sheet. We found that 62 % of the seasonal and 67 % of the decadal surface height variability are due to variations in firn air content rather than firn mass. Comparison of simulated surface elevation change with a previously published multi-mission altimetry product for the period 2003–2015 shows that performance of the updated model has improved, notably in Dronning Maud Land and Wilkes Land. However, a substantial trend difference (>10 cm yr−1) remains in the Antarctic Peninsula and Ellsworth Land, mainly caused by uncertainties in the spin-up forcing. By estimating previous climatic conditions from ice core data, these trend differences can be reduced by 38 %

A cluster of blood-based protein biomarkers associated with decreased cerebral blood flow relates to future cardiovascular events in patients with cardiovascular disease

Biological processes underlying decreased cerebral blood flow (CBF) in patients with cardiovascular disease (CVD) are largely unknown. We hypothesized that identification of protein clusters associated with lower CBF in patients with CVD may explain underlying processes. In 428 participants (74% cardiovascular diseases; 26% reference participants) from the Heart-Brain Connection Study, we assessed the relationship between 92 plasma proteins from the Olink® cardiovascular III panel and normal-appearing grey matter CBF, using affinity propagation and hierarchical clustering algorithms, and generated a Biomarker Compound Score (BCS). The BCS was related to cardiovascular risk and observed cardiovascular events within 2-year follow-up using Spearman correlation and logistic regression. Thirteen proteins were associated with CBF (ρSpearman range: −0.10 to −0.19, pFDR-corrected &lt;0.05), and formed one cluster. The cluster primarily reflected extracellular matrix organization processes. The BCS was higher in patients with CVD compared to reference participants (pFDR-corrected &lt;0.05) and was associated with cardiovascular risk (ρSpearman 0.42, p &lt; 0.001) and cardiovascular events (OR 2.05, p &lt; 0.01). In conclusion, we identified a cluster of plasma proteins related to CBF, reflecting extracellular matrix organization processes, that is also related to future cardiovascular events in patients with CVD, representing potential targets to preserve CBF and mitigate cardiovascular risk in patients with CVD.</p