BY AMY SYNNOTT
The late Canadian physician William Osler, who has been described as one of the “greatest diagnosticians ever to wield a stethoscope,” famously quipped, “Man is only as old as his arteries.” In addition to the hazard of plaque and atherosclerosis, Dr. Osler may well have been talking about a less well-known condition, arterial stiffness, a key biomarker that predicts cardiovascular and other chronic diseases.
While clinicians typically measure brachial blood pressure and cholesterol, neither of these biomarkers show what is going in the large arteries closest to the heart, where it matters most. “Hard arteries are a canary in the coal mine of arterial health, an early biomarker that may help clinicians predict [and hopefully prevent] heart attack, stroke, heart disease and other chronic degenerative diseases,” says Raymond Townsend, M.D., Director of Hypertension at the University of Pennsylvania School of Medicine.
The good news: “Using non-invasive measures, cardiologists can now predict how rigid vessels are by measuring how fast a pulse wave travels through the vascular system,” explains Dr. Norman Chideckel, a NYC-based vascular surgeon affiliated with Mount Sinai. The higher the number, the stiffer the artery, and the more likely a patient will be to experience heart attack, heart failure or stroke.
What is Arterial Stiffness?
The walls of large arteries, especially the aorta, lose elasticity over time, as elastin degrades and is replaced by rigid collagen fibers in the arterial wall, Townsend explains. “This stiffening of blood vessels is a normal part of the aging process. Your body stops making elastin in puberty and then it has to last the rest of your lifetime.”
The Framingham Heart Study showed patients with increased arterial stiffness were 48% more likely to develop cardiovascular disease. Loss of elasticity in the arteries predicts future risk of Type 2 diabetes than blood pressure alone, according to a study just published in Hypertension, a journal of the American Heart Association.
Doctors measure arterial stiffness using pulse wave analysis, which can tell them how fast blood pressure waves are moving down the vessel, Dr. Townsend says. “The stiffer the vessel, the faster the blood moves.”
How Stiff Arteries Affect Circulation
With each beat, the heart pushes blood out to the arteries (systole) and then relaxes or closes (diastole) as the blood comes back from the peripheral tissues, Joseph Raffaele, M.D., says. “Now imagine what happens when the tube-like balloon that is a healthy aorta is replaced by a metal pipe. That is what arterial stiffness is like.”
“A healthy aorta doesn’t just pump out blood, it also functions like a cushion, slowing blood down as it moves as the pulse waves bounces around within elastic arterial walls,” Dr. Raffaele says. “If the walls of the aorta become rigid, this cushioning disappears, causing the blood to move more quickly through the arteries [which translates as an increased pulse-wave velocity].”
And when this high pulse wave of blood reaches the fragile capillaries, it hits a wall, Dr. Raffaele explains. Some of the blood gets through, but some of the reflected pulse waves are returned to the heart too quickly while that organ is still trying to pump blood out (the systole phase), says Dr. Raffaele. “This puts an enormous strain on the heart.”
A fast pulse wave can also damage the delicate capillaries, Dr. Raffaele explains. “As you get older, your body produces less nitric oxide which forces these tiny vessels to contract. And when the capillaries become smaller and more damaged, less blood is able to reach key organs, like the kidneys and the brain.”
What Causes Arterial Stiffness?
Dr. Raffaele says there are many variables that may contribute to arterial stiffening, including a sedentary lifestyle, obesity, a high fat/high sugar diet, smoking, excess alcohol, stress, and various deficiencies (most notably of vitamins B and D).
These negative lifestyle factors increase oxidative stress in the body, triggering inflammation which then torches pliant elastin in the arteries, replacing it with rigid collagen, explains Dr. Townsend. “It’s like the arterial walls are being replaced with scar tissue.”
Why Measuring Central Blood Pressure Is Important
Unlike brachial blood pressure, which only measures pressure at the brachial artery, central blood pressure uses pulse wave analysis to estimate how arterial stiffness affects the pressure of blood coming out of the aorta, Dr. Townsend explains.
“Measuring central aortic blood pressure (also known as CBP) gives you a more accurate and complete picture of what’s really going on where it matters most: near the heart, he says. “Let’s face it: No one ever dies of an arm attack.”
It’s never been more clear that tracking your blood pressure is one of the No. 1 ways you can proactively manage your health and reduce your risk of cardiovascular events like heart attack or stroke. But don’t wait for your doctor to sound the alarm bell. With up to one third of Americans unaware they suffer from hypertension, the first sign you may have a problem could be a heart attack or stroke, according to the CDC.
Fortunately, today there are simple and inexpensive at-home monitors that make it easier than ever to track your vitals. In the time it takes to brew a cup of coffee, you could gain valuable insight into your health that could add years to your life.
The Importance of 24-Hour Home Blood Pressure Monitoring
Tracking your blood pressure is one of the number one ways you can proactively manage your health and reduce your risk of cardiovascular events like heart attack or stroke. But don’t wait for your doctor to sound the alarm bell. With up to one third of Americans unaware they suffer from hypertension, the first sign you may have a problem could be a heart attack or stroke, according to the CDC.
Investing in a home blood pressure monitor that can track both central and brachial blood pressure over the course of the day gives you the most accurate picture of your vascular health. Taking your blood pressure once a day provides an incomplete picture because blood pressure fluctuates during the day according to a 2004 review in the Journal of Human Hypertension. Furthermore, in office blood pressure readings are often skewed by so called “white coat hypertension” a phenomenon in which blood pressure spikes in a medical setting likely due to stress. Experts say you should measure your blood pressure twice a day, morning and night, at the same time everyday. For more information about how to take your blood pressure at home, read our comprehensive guide on How to Get An Accurate Blood Pressure Measurement at Home.