Testing It Up

Researchers from the University of Zurich say a safe, simple eye test may someday offer an effective way to distinguish individuals who are at high risk of stroke.

The test is called ocular pulse amplitude (OPA) which could be performed by ophthalmologists during routine exams. It can detect carotid artery stenosis (CAS), a condition that clogs or blocks the arteries that feed the front part of the brain, which is a known risk factor of stroke.

Lead researcher Pascal Bruno Knecht, M.D., shares “Our results show that ocular pulse amplitude is a reliable, safe screening test for carotid artery stenosis. We recommend further study to confirm the value of using OPA to detect and assess the severity of CAS and to define its use in stroke prevention.”

Every year, there are approximately 795,000 Americans who suffer a new or recurrent stroke, and about 137,000 of these people die as a result. Individuals with severe CAS are believed to be at higher risk of suffering stroke. Consequently, doctors would want to control the problem and treat CAS before more cases are reported. At present, there is no efficient test available to detect the disease and it doesn’t help that CAS remains asymptomatic.

The U.S Preventive Services Task Force had likewise performed a research review which indicated that if an efficient screening test for CAS were available, the incidence of stroke and fatalities due to stroke could be substantially reduced.

A compound found in such citrus fruits as oranges and grapefruits has been associated with lower stroke risk in women. A new study was able to identify flavanoids in citrus fruits, known as flavanones, which seem to provide the most protection against strokes. Flavanoids are antioxidant compounds that give fruits and vegetables their vibrant colors; they are also present in chocolate and red wine.

The study found that women whose diets included the most amount of flavanones had 19 percent lower risk of suffering from a blood-clot-related stroke, when compared against women who had the lowest intake of the compound.

Researcher Kathryn M. Rexrode, MD, MPH, of the Harvard Medical School and Brigham and Women’s Hospital, shared: “Our study supports the conclusion that flavanones are associated with a modest reduction in stroke risk.”

Rexrode and her colleagues at Harvard worked with researchers from Norwich Medical School in the United Kingdom in an attempt to achieve a better understanding of the impact of six specific sub-types of flavonoids on stroke risk. Their efforts consisted of performing an analysis on 14 years’ worth of follow-up data on nearly 70,000 female nurses, who participated in a nationwide study on women’s health.

The participants were asked to fill out questionnaires detailing the foods they ate, upon enrollment into the study and every four years after.

Rexrode clarifies, however, that there is a need for further research in order to confirm their findings. “I would certainly not recommend that anyone take flavanone supplements based on this research,” he said.

A study presented at a conference of the American Heart Association associated a person’s blood type with stroke risk. People who whose blood type is O, the most common blood type, are said to be less likely to suffer from a stroke when compared against people whose blood type is AB, and women whose blood type is B.

Dr. JoAnn Manson, chief of preventive medicine at Harvard’s Brigham and Women’s Hospital and one of the leaders of the study, said: “There’s increasing evidence that blood type might influence risk of chronic disease… It’s not at the level where we want to alarm people and we want to make that clear. But it’s one more element of risk that people would want to know about, and it could give them one more reason to keep blood pressure and cholesterol in line.”

The study, led by Dr. Lu Qi of Brigham and Women’s Hospital, involved an analysis of data from 90,000 men and women, who participated in two observational health studies that spanned a period of more than 20 years.

The researchers found that in the 2,901 strokes that occurred among the study participants, people whose blood type was AB had 26 percent increased risk of suffering from a stroke, when compared against people whose blood type was O. In addition, women whose blood type was B had 15 percent increased risk of suffering from a stroke, when compared against people whose blood type was O.

A study that compared two ways used to clear fatty plaque from carotid arteries was presented on Friday at a meeting in San Antonio that discussed stroke medicine, according to a feature on The Wall Street Journal.

The ten-year study, called CREST, was federally-funded. It indicated that the use of stents, which is a less invasive option when compared to surgery, is just as effective as the latter “in terms of safety and effectiveness.” The procedure, which necessitates a shorter stay in the hospital, is said to be restricted by the federal Medicare program “to patients with previous stroke symptoms and who are at high surgical risk”.

The article wonders whether the results of this study may become the catalyst for a change in this prevalent ruling and pave the way to making the stenting procedure a reimbursable option for a wider variety of patients and cases.

One of the investigators involved in the study, L. Nelson Hopkins (chairman of neurosurgery at the State University of New York at Buffalo), said that “If you properly train to do this procedure, the two procedures are equal.”

Stents look like small, tubular scaffolding. In a previous post, it was mentioned that stents were inserted to reopen the clogged arteries of former President Bill Clinton.

The study looked into the cases of more than 2,500 patients, and of this population about half did not suffer any symptoms; they were also said to have benefited equally from stents and surgery. Every year, though, there are only 30,000 procedures involving carotid-stent placement over 100,000 carotid operations.

New York Health Screening