Cross-organ MRI to assess the relationship between cardiac traits and cerebral white matter hyperintensity volumes

BACKGROUND: Cardiac disease is linked to early cognitive decline and dementia, with shared risk factors such as hypertension, inactivity, and APOE4 genotype. White matter hyperintensities (WMH) may mediate this association. METHODS: We investigated associations between 29 cardiac MRI (CMR) measures and 5 regional WMH volumes independently of known CVD risk factors. We analysed 30,961 UK biobank participants without pre-existing cardiovascular disease (CVD) or known dementia. We empirically validated the CMR traits by associating these to incidence CVD using Cox's regression models. Linear regression models were used to identify association between 6 regional WMH volumes and cognitive tests outcomes (executive function and processing speed), as well as with 29 CMR traits. RESULTS: Twenty-one CMR traits associate with heart failure and atrial fibrillation, 10 with coronary heart disease, and 4 with abdominal aortic aneurysm. Frontal and parietal WMH volumes associate with executive function and processing speed. We identify distinct groups of CMR associations where right heart traits (excluding RVEF) primarily associate with parietal WMH volumes, contrasting with the more widespread associations of left cardiac and aortic traits. Higher values of aortic areas, LV mass and wall thickness associate with higher WMH volumes for all brain regions. Furthermore, increased WMH volumes associate with increased minimum and maximum ascending aortic areas. We additionally observe associations between increased biventricular ESV and increased WMH volumes, with increased EF associating with lower WMH volumes. CONCLUSIONS: We show that CMR derived measurements of function and structure associate with regional WMH volumes implicated in executive functioning and processing speed, independently of known cerebrovascular risk factors in people without established disease.