A urine test may soon replace the D-dimer to screen for DVT (deep vein thrombosis) blood clots.
Imagine being in the ER with a suspected DVT (deep vein thrombosis), and instead of getting your blood drawn for the D-dimer test, you’re asked to give a urine sample because the nurse says, “We can see if you might have a blood clot by analyzing your urine.”
This scenario may soon be standard in ERs, thanks to a study led by Timothy Fernandes, MD.
The study report was published in 2014, but detecting a deep vein thrombosis with the patient’s urine is still not a standard procedure in emergency rooms.
But imagine the possibilities:
Detection of a DVT through urine would make it simple and easy to do in a regular medical clinic.
My mother has had her D-dimer level evaluated at least three times when she presented to the ER with symptoms that a DVT can cause.
Each time, the D-dimer was positive, and because of that, a CT scan of her chest was ordered to see if there was blood clot in her lungs (pulmonary embolism).
The CT scans were negative all those times. A positive D-dimer doesn’t always mean a blood clot. However, this tests helps guide physicians in what to do next.
“Physicians, especially in the emergency room, are often faced with patients with symptoms and risk factors concerning for DVT/PE,” says Dr. Paramjit “Romi” Chopra, MD, founder of the Midwest Institute for Minimally Invasive Therapies (MIMIT), an interventional radiology and endovascular therapy practice.
“Like most screening exams, D-dimer is a blood test with a high sensitivity and low specificity for diagnosing PE.
“However, some studies have shown that fibrinopeptide levels in the urine may have higher diagnostic accuracy than D-dimer.
“Ultimately, the key to diagnosing DVT/PE is a thorough history and physical exam by an experienced physician.”
What is fibrinopeptide?
FPB is a compound that’s released when a blood clot forms, and gets excreted through urine. Dr. Fernandez says in the report that the urine test is more accurate than the D-dimer.
That’s because the D-dimer protein fragment becomes present in the blood after the DVT begins to break down.
Whereas the FPB is present in the blood before the DVT begins degrading, while the thrombus is still active.
The urine test, though, is still not refined enough to become a replacement for the D-dimer test.