This is not a new methodology, since arterial stiffness, assessed from the measurement of the pulse wave velocity between the carotid and the femoral arteries, had first been described in 1922. But, as discussed above, this is the first epidemiological demonstration of the predictive value of this index, and a strong argument for using this index to assess the cardiovascular risk more carefully. 

My group has been working on the arterial phenotype for many years, mainly the elastic properties and the geometric remodelling of large arteries. As clinical pharmacologists, Dr. Pierre Boutouyrie and I intended to determine the drugs which are the most efficient to correct abnormalities occurring with aging, hypertension, and atherosclerosis. My group, and particularly Dr. Patrick Lacolley, also studied the structure-function relationship of the large arteries, to find out the major molecular determinants of elastic properties, not only the well-known elastin and collagen compounds but also other components like the adhesion molecules which modify the tri-dimensional organization of the arterial wall.

  Could you summarize the significance of your paper in layman's terms?

In this paper, we determined the predictive value of aortic stiffness, assessed from the measurement of pulse wave velocity (PWV), on total and cardiovascular mortality.  The higher the stiffness of the aorta, the higher the risk to die from any cause or from cardiovascular diseases. When the stiffness of the aorta increases, the resistance of the heart pump to ejection is increased. Two mechanisms contribute to myocardial infarction—the hypertrophy of the heart muscle and the restriction of blood perfusion to the heart muscle. When a physician estimates the risk for a patient to undergo a cardiovascular complication, he generally uses parameters like age, presence of hypertension, diabetes, etc., to calculate a score. Our view is that aortic stiffness, by itself, integrates all the damages done to the arteries by these cardiovascular risk factors. Thus, by measuring aortic stiffness, the estimation may even be better than by calculating a cardiovascular risk score. This is what we have demonstrated in a second paper (Boutouyrie P., Tropeano A.I., Asmar R., Gautier I., Benetos A., Lacolley P., Laurent S. "Aortic stiffness is an independent predictor of primary coronary events in hypertensive patients: a longitudinal study." Hypertension, 39: 10-15, 2002.).

PWV is a velocity, thus it is calculated by dividing a distance by a time. The distance is that between the carotid artery (estimating the ascending aorta) and the femoral artery, thus covering the travel of the pressure wave along the ascending and descending aorta. This is a noninvasive transcutaneous measurement, done by placing the mechanical transducers over the common carotid artery and the common femoral artery, and recording the pressure wave on a computer. The time spent by the wave to travel from the carotid (i.e. the ascending aorta) to the femoral artery is calculated as the time-delay between the feet of the two pressure-waveforms. This can also be measured with two Doppler probes. In that case, this is not the pressure wave which is taken into account, but the flow wave. With a short training, PWV can be easily measured in most patients, by a physician, a nurse, or a technician. In some clinical departments interested in PWV measurement, it is done routinely in all patients. It is not expensive, and can be done in 15 minutes’ time.