Impact of cardiovascular risk factors on myocardial blood flow in patients with presumably unobstructed coronary arteries: Results from the Stuttgart myocardial perfusion registry

Abstract Background Non-invasive quantification of myocardial blood flow (MBF) has emerged as a valuable tool for the detection of coronary artery disease. Recently, fully automated MBF assessment using cardiac magnetic resonance imaging (CMR) has become available. However, data on the influence of cardiovascular risk factors and patients´ characteristics (such as age, BMI, and gender) on MBF remain limited and partially conflicting. Purpose The aim of this study was to assess the impact of cardiovascular risk factors on MBF in individuals without evidence of regional inducible ischemia, indicating the absence of obstructive epicardial coronary artery disease. Methods This analysis included consecutive patients who underwent vasodilator stress CMR at our institution between 2023 and 2025. First-pass myocardial perfusion was assessed both visually and quantitatively using an MRI sequence with fully automated inline MBF quantification. All included patients had a negative stress CMR by routine qualitative criteria, defined as the absence of ischemic late gadolinium enhancement (LGE), perfusion defects, valvular disease, or structural heart abnormalities. Patients with insufficient vasodilator response—defined as stress MBF (SMBF)