Measurements of more than 1,700 people with mildly high blood pressure over nearly eight years found a direct relationship between the degree of aortic stiffness and incidence of stroke, says a report by Dr. Stéphane Laurent and his colleagues at the Hospital European Georges Pompidou in Paris. Their finding appears in the April 4 online issue of Stroke.
They measured aortic stiffness with a machine that sends an ultrasound pulse wave through the chest. The speed of the wave, called pulse wave velocity (PWV), shows the stiffness of the aorta. "With a short training, PWV can be measured in most patients by a physician, a nurse or a technician," Laurent says.
There was a 72 percent increase in the risk of fatal stroke for every four meters per second of PWV, the report says. Aortic stiffness is a warning sign for other cardiovascular problems, such as heart attack, they add.
Laurent says measurements of arterial stiffness are used routinely at the Paris hospital. "I measure arterial stiffness initially and every one or two years in my patients," Laurent explains, to help decide a course of treatment and then to check a patient's progress.
But the technique is not widely used, Laurent acknowledges. "This way of doing is rather limited to a few centers in France, also involved in research about arterial stiffness. We are in the process of convincing cardiologists and general practitioners of the usefulness of this parameter."
The study confirms a growing interest among cardiologists about the value of arterial stiffness as a marker of risk, says Dr. Richard A. Stein, chief of cardiology at the Brooklyn Hospital Center and a spokesman for the American Heart Association.
Some degree of arterial stiffness is inevitable, "one of the irrevocable changes of aging," as flexible fiber in the blood vessel wall is replaced by stiffer tissue, Stein says. Blood pressure goes up because the aorta cannot expand as well as it once did when a heartbeat sends blood surging into it.
There are several indirect ways of measuring arterial stiffness, Stein says. One is to look at pulse pressure, the difference between systolic pressure and diastolic pressure, the high and low points of a reading. "A number of epidemiologic studies show that pulse pressure is more indicative of risk than either blood pressure reading, he says.
For practical purposes, a high arterial stiffness reading won't have a great effect on treatment, Laurent says. Patients will still be given the standard drugs to reduce blood pressure, with greater emphasis on other known risk factors, such as high cholesterol.
While Stein praises the study, he says, "We must wait to see what this adds to the measurements of risk we already obtain." And while drugs aimed at reducing arterial stiffness are being developed, large-scale studies will be needed to determine their usefulness, Laurent says.
You can refresh your memory of the health problems of blood pressure and how it is treated by consulting the American Heart Association. Try the National Institute of Neurological Disorders and Stroke for more about brain attacks.