Aortic Stiffness Index (ASI) Calculator

Aortic Stiffness Index (ASI): Explanation and Clinical Context The Aortic Stiffness Index (β) is a non-invasive echocardiographic measure of the intrinsic stiffness of the ascending aorta. It reflects the mechanical properties of the aortic wall and is calculated using systolic and diastolic blood pressures and the corresponding aortic diameters. An increased ASI indicates reduced aortic compliance and is associated with aging, hypertension, and increased cardiovascular risk.

Normal reference values vary by age, but generally, an ASI below 5 is considered normal, while higher values suggest increased stiffness. This index is clinically relevant as it correlates with left ventricular afterload, arterial hypertension complications, and long-term cardiovascular outcomes.