URINE TEST COULD HELP SPOT BLOOD CLOTS

A new study by researchers from California and Canada indicates a simple urine test can indicate the presence of venous thromboembolism, a blood clot that has broken free from its point of origin and which travels through the bloodstream, eventually lodging in a vein. The test evaluates the levels of fibrinopeptide B (FPB), a small peptide that's released when a thrombosis forms and which is removed from the body through urine

The results of the study will be presented at the American Thoracic Society's 2014 International Conference here.

Study lead author Timothy Fernandes, M.D., M.P.H., said the study was developed based on the results of a pilot trial that suggested that urine FPB levels could be used as a screening tool for venous thromboembolism in patients at risks for clots. "The urine FPB test offers advantages over other screening methods because it doesn't require blood to be drawn and it can provide more accurate results than the D-dimer test," Fernandes said.

The D-dimer test looks for blood evidence of a protein fragment called D-dimer that is present in the blood after a clot begins to break down. The FPB test has the potential for greater specificity because it can reflect ongoing clot activity, while D-dimer can only be measured once a clot has already become degraded.

"During our study, we validated the sensitivity, specificity and likelihood ratios for several diagnostic thresholds of urine FPB using stored urine samples from the Fernandes said.

The researchers used stored urine samples taken from 344 patients who participated in the Pulmonary Embolism Diagnosis Study (PEDS), a multicenter study of 1,417 patients considered likely to have an acute pulmonary embolism. For all urine samples, the researchers measured the FPB concentration and evaluated the sensitivity and specificity of the test at various cut-off points in relation to its ability to predict the presence of venous thromboembolism.

What they found was at concentrations of 2.5 ng/ml, urine FPB demonstrated sensitivity comparable to previously published values for plasma latex and whole blood D-dimer levels, but with greater specificity.

"The results of our study indicate that urine FPB tests may be a useful complement to current biomarkers such as D-dimer to measure for the presence and activity of venous thromboembolism," Dr. Fernandes said. "As an addition to other types of testing, FPB urine provides greater specificity and doesn't require a blood draw, which can be a major boon to patients."

The patent for the urine fibrinopeptide B test is held by the University of California Board of Regents. Dr. Fernandes and his co-authors plan on developing a urine dipstick test for FBP that could be quickly and widely applied.

Future studies are planned to assess urine fibrinopeptide B in other settings where D-dimer is used including use of urine fibrinopeptide after anticoagulation to determine the risk of recurrent venous thromboembolism.

MIGRAINE WITH AURA MAY LEAD TO HEART ATTACK BLOOD CLOTS FOR WOMEN

Women who have migraines with aura, which are often visual disturbances such as flashing lights, may be more likely to have problems with their heart and blood vessels, and those on newer contraceptives may be at higher risk for blood clots, according to two studies released today that will be presented at the American Academy of Neurology's 65th Annual Meeting in San Diego, March 16 to 23, 2013.

The first study showed that migraine with aura is a strong contributor to the development of major cardiovascular events such as heart attack and stroke. The Women's Health Study involved 27,860 women, 1,435 of whom had migraine with aura. During the 15-year study, there were 1,030 cases of heart attack, stroke or death from a cardiovascular cause. The study examined the relative contribution of various vascular risk factors to these major cardiovascular events.

"After high blood pressure, migraine with aura was the second strongest single contributor to risk of heart attacks and strokes," said study author Tobias Kurth, MD, ScD, of INSERM, the French National Institute of Health and Medical Research in Bordeaux and Brigham and Women's Hospital in Boston. Kurth is also a Fellow of the American Academy of Neurology. "It came ahead of diabetes, current smoking, obesity, and family history of early heart disease."

Kurth cautioned that while people with migraine with aura have an increased risk, it does not mean that everyone with migraine with aura will have a heart attack or stroke. He said people with migraine with aura can reduce their risk in the same ways others can, such as not smoking, keeping blood pressure low and weight down and exercising.

The second study looked at women with migraine who take hormonal contraceptives and the occurrence of blood clots. The study involved women with migraine with and without aura who were taking both newer contraceptives such as the contraceptive patch and ring and older contraceptives. Of the 145,304 women who used the contraceptives, 2,691 had migraine with aura and 3,437 had migraine without aura.

Women with migraine with aura were more likely to have experienced blood clot complications such as deep vein thrombosis with all types of contraceptives than women with migraine without aura. For example, 7.6 percent of women with migraine with aura who used a newer generation combined hormonal contraceptive had deep vein thrombosis compared to 6.3 percent of women with migraine without aura, but the timing of the two events is not clear. The occurrence of blood clot complications was also higher in women with migraine who took contraceptives than women taking the contraceptives who did not have migraine.

"Women who have migraine with aura should be sure to include this information in their medical history and talk to their doctors about the possible higher risks of newer contraceptives, given their condition," said study author Shivang Joshi, MD, MPH, RPh, of Brigham and Women's Falkner Hospital in Boston and a member of the American Academy of Neurology.

Kurth's study was supported by the National Institutes of Health. Joshi's study was supported by the Graham Headache Center Research Fund.