Normal and reference values for MRI-based pulse wave velocity in the middle-aged general population

Background Aortic stiffness, assessed through pulse wave velocity (PWV), is an independent predictor for cardiovascular (CV) risk. However, the scarce availability of normal and reference values for magnetic resonance imaging (MRI) based PWV is limiting clinical implementation. Purpose The aim of this study was to determine normal and reference values for MRI-PWV in the general population. Methods From the 2,484 participants of the NEO study that have available MRI-PWV data, we selected 1,639 participants that were free from CV disease or treatment for diabetes, hypertension or dyslipidaemia (age range 45–65 years, 51% male). Participants were categorized by sex, age and blood pressure (BP) subgroups. Normal values were specified for healthy (<130/80 mmHg) and elevated BP (≥130/80 and <140/90 mmHg) and reference values for high BP (≥140/90 mmHg) subgroups. Differences between groups were tested with either an independent samples t-test or ANOVA. Results Overall mean PWV was 6.5 m/s [95% CI 6.4–6.6]. PWV increased significantly with advancing age and BP categories (both p<0.001). There was no difference in PWV between men and women, however a stronger increasing trend for women above 55 years old was observed (figure). The 95% CI's were smaller for participants <55 years old as compared to participants >55, indicating an increasing variability of PWV with age. The elevated PWV upper limits for the higher blood pressure subgroups are particularly evident in participants above 55 years old. Conclusion This study provides normal and reference values for MRI-assessed PWV per sex, age and blood pressure category. PWV percentiles (10, 25, 50, 75 and 90th) Funding Acknowledgement Type of funding source: Public hospital(s). Main funding source(s): The NEO study is supported by the participating departments, the Division and the Board of Directors of the Leiden University Medical Centre, and by the Leiden University, Research Profile Area “Vascular and Regenerative Medicine”