Arterial stiffness index: A new evaluation for arterial stiffness in elderly patients with essential hypertension

Background: Arterial stiffness is one of the predictors of cardiovascular event. Arterial stiffness is commonly measured by pulse wave velocity between the carotid and femoral arteries. Recently the arterial stiffness index which is measured by computerized oscillometry at the upper arm was developed. As this procedure is a convenient means of measuring pulse wave velocity, we considered it suitable to evaluate arterial stiffness in elderly patients. We evaluated this arterial stiffness index and compared it with other methods of evaluating arterial stiffness in hypertensive patients, including the elderly. Methods: Forty‐two patients with essential hypertension, including 26 subjects over 60 years old were enrolled. We evaluated the arterial stiffness index by computerized oscillometry, and also evaluated arterial stiffness between the carotid‐femoral artery and the brachial‐tibial artery, the second derivative of photoplethysmogram, the forearm vasodilator response to reactive hyperemia by strain‐gauge plethysmography. Results: Arterial stiffness index was positively correlated with pulse wave velocity between the carotid‐femoral artery (P < 0.0001; r = 0.579), the heart‐carotid artery (r = 0.454) and right brachial‐tibial artery (r = 0.549). It was also correlated with b/a (r = 0.474) and d/a (r = 0.568) by a second derivative of photoplethysmogram, but not correlated with a reactive vasodilator response. In elderly patients, arterial stiffness index was also correlated with carotid‐femoral pulse wave velocity (P < 0.05; r = 0.456) but not correlated with a vasodilator response to reactive hyperemia. Conclusion: These data suggest that arterial stiffness index is correlated to common pulse wave velocity between the carotid and femoral arteries, so this index might be useful to evaluate arterial stiffness in hypertensive patients including the elderly.