WP1-3 included magnetic resonance imaging (MRI) scans of the heart and the brain of VCI patients (WP1), HFpEF and aortic stenosis patients (WP2) and elderly general population used as control (WP3). Scanning for WP1 took place in Maastricht NL, and for WP2 in Pamplona ES and London UK, and for WP3 in London UK. Beyond the MRI scans, we also looked at other measures of microvascular density and health including optical coherence tomography – angiography (OCTA), sublingual measurements with the Glycocheck instrument, as well as collecting blood to look at circulating biomarkers. General measures of cognitive function and cardiac function were also collected for all patients. The study protocols were all approved by the corresponding Ethics Committee. A common protocol was established for the different sites. The scans and data collection between locations were homogenized. All patients have been recruited and the data analysed. In all three patient populations, we analysed how cardiac function affected blood flow in the brain and cognitive function. We analysed brain blood flow and compared the amount of blood flow in patients with cognitive impairment to those with heart failure, to those from the general elderly population. In the brain, we also studied with IVIM the brain microstructure and micro-perfusion and investigated a novel MRI technique called cerebral Vessel Architecture Imaging, by which lower vessel densities (i.e. vascular rarefaction) were found in the brains of patients with VCI compared to controls. In the heart we evaluated myocardial blood flow at rest and in stress conditions and the development of fibrosis. In addition, because the aortic stenosis underwent surgery and so we could collect a piece of the heart during surgery, we investigated how the heart tissue itself related to the MRI measurements. For the OCTA, we analysed whether the measurements related certain measures of VCI and of HFpEF. For the Glycocheck, we compared how the Glycocheck measurements related to the MRI measurements of blood flow. For the circulating biomarkers, we checked both proteins transported in the blood and small fragments released by different cells called extracellular vesicles. We investigated the correlation of the circulating proteins and disease progression. We identified circulating biomarkers related to microvascular dysfunction and several genes that were altered in the circulating extracellular vesicles in disease.
In WP4, we used a preclinical model of HFpEF and VCI (ZSF1 obese rat model) and applied comparable MRI techniques to those used in the clinical WP1-3, as well as imaging with the Glycocheck and collecting blood for circulating factors. By using this experimental model, we could investigate whether (1) the MRI measurements changed only early in disease progression and (2) compare the MRI measurements to direct measurements of vessel density and function.
In WP5, we investigated how the comorbidities associated with HFpEF and VCI affect brain vascular health. We used an imaging technique to measure blood flow in the brain of our preclinical model of comorbidities. We established when cognitive function declines in these rodents and used genetic analyses on isolated brain blood vessels to investigate the gene expression changes.
In WP6, we investigate changes in gene expression in the heart and brain of the ZSF1 obese rat model. This was done either on isolating endothelial cells (bulk RNA-Seq) or on individual cells (single cell RNA-Seq). We analysed metabolic changes and combined with spatial analysis of the lipids that are present to understand changes in lipid handling.
WP7 studied the cause of microvascular dysfunction in the heart. We initially hypothesized that a protein called Pitx2 was involved in microvascular rarefaction (the process by which vessel density is lost). Knocking out Pitx2 did induce rarefaction but this alone did not cause HFpEF. We therefore investigated other aspects of microvascular dysfunction in the heart of the ZSF1 obese rats. We found a loss of pericytes, a cell type that surrounds capillary blood vessel, was important and investigated the mechanism by which pericytes contribute to HFpEF.
Concerning the management and dissemination activities of the project, a communication and dissemination strategy was put in place. Our partner Crowdhelix created a Vascular Helix on their platform to enhance communication across the vascular fields on result dissemination but also to increase collaborations on upcoming projects. The virtual collaboration community has 544 experts from 191 organizations across 42 countries at the end of the project. We published 33 scientific articles. We presented at an array of different conferences. We attended a patient conference to speak directly to patients with heart failure. We produced a written article for the patients as well. We identified and developed several Key Exploitable Results from our research that can be further exploited by the partners and by the wider research community in the future. We engaged the EU Horizon Results Booster, to support our team in identifying potential exploitation and commercial pathways, including an assessment of Patent protection for key innovations.
