KnöchelArmIndex

KnöchelArmIndex, often abbreviated as KAI or BAI, is a medical measurement used to assess arterial stiffness. It is calculated by comparing the systolic blood pressure in the ankles to the systolic blood pressure in the arms. Specifically, the KAI is the ratio of the ankle systolic blood pressure to the brachial (arm) systolic blood pressure. A normal KAI is generally considered to be between 1.0 and 1.3.

An elevated KAI, typically above 1.3, can indicate peripheral artery disease (PAD) or increased arterial stiffness. Arterial stiffness is a risk factor for cardiovascular diseases, including hypertension, stroke, and heart attack. The KAI is a non-invasive and relatively simple test that can be performed with standard blood pressure cuffs and a Doppler ultrasound device.

The measurement involves taking blood pressure readings at both the brachial arteries in the arms and the posterior tibial or dorsalis pedis arteries in the ankles, usually while the patient is lying down. The systolic pressures are then divided to obtain the KAI. While the KAI is a useful screening tool, it is important to note that other factors can influence the reading, and it should be interpreted in conjunction with a comprehensive clinical assessment. A low KAI, below 1.0, can sometimes suggest significant lower extremity artery stenosis, which may require further investigation.