Cerebral perfusion features linking subclinical cardiac and aortic dysfunction to vascular brain injury.

INTRODUCTION: Subclinical cardiovascular remodeling may impair cerebral hemodynamics and contribute to dementia, but the perfusion features linking subclinical cardiovascular dysfunction to cerebrovascular injury remain unclear. METHODS: We studied 1748 UK Biobank participants with cardiac magnetic resonance imaging (MRI), arterial spin labeling (ASL) MRI, and structural brain MRI. Six cardiac MRI biomarkers were analyzed individually and as a composite score. Cerebral perfusion was assessed by cerebral blood flow (CBF) and arterial transit time (ATT). RESULTS: Greater subclinical cardiac and aortic dysfunction was associated with lower CBF and prolonged ATT. Participants with low CBF and prolonged ATT had the greatest white matter hyperintensity (WMH) burden, equivalent to 5.5 years of age-related accumulation. CBF and ATT jointly mediated 53% of the association between subclinical cardiac and aortic dysfunction and WMH burden. DISCUSSION: Impaired cerebral perfusion, captured by lower perfusion volume and delayed perfusion timing, may be a mechanism linking subclinical cardiovascular dysfunction to brain vascular injury.