We now have an early warning that can help people with diabetes prevent heart attacks and strokes. Until now, for many people the first symptom of a heart attack has been having one. I don't think that I have ever written about the complications of diabetes without offering some way to deal with them. That would be just too negative for either you or me, and I am not going to start being negative now.
Heart attacks are serious business, but we can prevent them. People with diabetes especially need to prevent them. The cause of most heart attacks is the buildup over time of a material called plaque on the endothelium, the thin layer of cells that line the interior surface of blood vessels. When some of that plaque breaks open, a blood clot forms there. Then, when the clot is large enough to cut off most of the blood flowing through that artery, we get a heart attack.
The cause of most strokes is similar, but they affect the blood vessels that supply blood to the brain. Clots that form in the blood vessels of the brain or neck or move there from other parts of the body, as well as a severe narrowing of an artery feeding the brain, do the damage.
The death certificates of 68 percent of people 65 or older list heart disease, and 16 percent list stroke. Adults with diabetes are two to four times more likely to die from a heart attack than other Americans. Our first line of defense against heart disease is a non-invasive, inexpensive, and easy-to-use device called the VENDYS, developed by Endothelix Inc. in Houston. VENDYS stands for vascular endothelial dysfunction. While I was in Houston a week ago to report on the annual convention of the American Association of Clinical Endocrinologists, I took the opportunity to meet the Endothelix people and check out the device at the company's headquarters.
The VENDYS device is preventative medicine against heart attacks and stroke. The U.S. Food and Drug Administration approved it in September 2007, and Endothelix started making it available in the past few months to researchers and to those medical doctors who are early adopters.
When Albert Yen, M.D., tested me, he hooked me up to the VENDYS device in two ways: Blood pressure cuffs and fingerstick temperature probes. He is the company's chief operating officer and vice president of medical affairs.
The key measurement was how fast the temperature in my fingertips rebounded after he released the blood pressure cuffs. Temperature measures how much blood is flowing. The extent of rebound is directly connected with the buildup of coronary plaque.
The test took just 15 minutes. Normally, a nurse or technician would handle it.
"One of the strengths of our device," Dr. Yen told me, "is that aside from putting on the blood pressure cuffs and the temperature probes on the fingertips, all that the technician has to do is to hit the start button on the software, which does all the data collection. That doesn't require a skilled operator." Endothelix offers a choice of two VENDYS systems, either cart-based or portable. The portable system, which includes a digital thermal monitor, a cuff management monitor, as well as a powerful portable computer, is the more popular one. Endothelix sells it to researchers and medical practices for $9,900.
I told Dr. Yen that I was a bit concerned that the test might indicate that I have a heart problem. After all, I'm 73 years old and have had diabetes for 15 years.
So I was relieved when Dr. Yen finished testing me. "You have a great looking temperature curve here."
My VENDYS Test Results (Photo by David Panthagani of Endothelix)
"It dropped down appropriately after the cuff blocked your blood flow," he continued. "And after the cuff was released, the rebound shoots right back up. That's a healthy response. If that curve came down and struggled to come up, that would be a case of poor vascular activity. This is the nuts and bolts of what the test does."
My "vascular reactivity index" of 2.07 was within the good range. But if I had tested in the poor or intermediate range, I would need to be more aggressive with my exercise, Dr. Yen said. In that case, they would need to retest me in two months.
At the end of my visit to Endothelix I met with Morteza Naghavi, M.D., the company's CEO and founder. He says that, according to the literature of hundreds of papers on heart disease, endothelial dysfunction is the most sensitive marker. "We call it the vascular barometer," Dr. Naghavi said. "It's a barometer of vascular health, and you have a good number, David. Keep doing the good things you are doing for your health."
I plan to keep on exercising and taking control of my diabetes. I hope that you also continue to do the good things you are doing to help prevent heart disease. And while you're at it, you might consider asking your doctor to test your vascular endothelial function.