Exploratory Study of Stress Myocardial Blood Flow and Myocardial Perfusion Reserve in Relation to Cerebral Small Vessel Disease on MRI: A Hypothesis-Generating Analysis

Background: Small vessel disease of the heart and brain share common risk factors and pathophysiological mechanisms, but imaging-based evidence of a direct link between coronary microvascular dysfunction and cerebral small vessel disease (CSVD) remains limited. This study aimed to assess whether stress myocardial blood flow (MBF) and myocardial perfusion reserve (MPR) are associated with brain magnetic resonance imaging (BMR) markers of CSVD. Methods: This retrospective study included adult patients who underwent both cardiac magnetic resonance imaging (CMR) and BMR between January 2021 and December 2025 at a tertiary center. Quantitative stress MBF and MPR were assessed using adenosine stress CMR. BMR markers included Fazekas scores for periventricular and deep white matter hyperintensities (PVWM and DWM), and the number of cerebral microbleeds identified on susceptibility-based sequences. Spearman's rank correlation coefficients and partial correlations adjusted for age and imaging interval were calculated. Subgroup analyses were performed by scanner vendor and imaging interval. Results: A total of 51 patients met inclusion criteria (33 scanned on GE Healthcare systems and 18 on Siemens Healthineers systems). Fluid-attenuated inversion recovery imaging was available in 35 patients, and susceptibility-based sequences in 42. No statistically significant associations were observed between stress MBF or MPR and PVWM, DWM, or cerebral microbleeds in either vendor group after adjustment for age and imaging interval. Findings were consistent in analyses restricted to CMR–BMR intervals ≤ 5 years. Conclusion: This exploratory study did not identify statistically significant associations between stress MBF or MPR and MRI markers of CSVD.