Scans May Aid Blood Clot Treatment
Can measure size of lung embolisms and prioritize therapy
TUESDAY, March 2, 2004 (HealthDayNews) -- In a possible bit of good news for people prone to blood clots, researchers report that a new kind of scan can predict which patients need the most drastic treatments for clots in the lungs.
The findings are preliminary and need to be confirmed. But if they hold up, they'll help doctors do a better job of diagnosing and treating the potentially deadly clots, says study co-author Dr. John A. Pezzullo, an assistant professor of diagnostic imaging at Brown University. "It may allow us to stratify these patients and say this patient needs more aggressive treatment to survive," he explains.
Lung blood clots -- also known as pulmonary embolisms, or emboli among linguistic perfectionists -- strike an estimated 600,000 Americans a year and kill 50,000 of them. Lung blood clots have been in the news as doctors have urged airline passengers to beware of the risk of developing them during long flights.
The clots typically break off from vessels in the legs and make their way to the lungs. Once there, they act like traffic jams, preventing the lungs from accepting blood from the heart and oxygenating it.
The symptoms of the clots include shortness of breath and chest pain, and it often takes doctors a while to figure out what is really going on. In recent years, however, scanning technology has given doctors more effective ways to figure out if the clots actually exist.
Pezzullo and his colleagues examined the medical records of 59 patients who had lung blood clots and underwent CT scans. The researchers report their findings in the March issue of Radiology.
Doctors currently use the scans to determine whether the clots exist; the researchers took them a step further and used the results to measure the size of the clots. Five of the six patients with the largest clots died, while all but one of the 53 other patients survived.
"The amount of clot burden [the size of the clot] correlated pretty significantly with patient outcome, whether they survived or died," Pezzullo says.
In cases where patients seem to be at high risk, the scan results could point doctors to more powerful treatments. Among other things, doctors can try to destroy clots by giving drugs to patients or actually injecting drugs into the clots themselves. However, surgery itself can be risky.
Researchers will have to confirm the findings in studies of larger groups, Pezzullo cautions.
Another radiologist agrees. The study is based on "very small numbers" and doesn't take into account other relevant factors such as blood pressure, says Dr. Paul Molina, a professor of radiology at the University of North Carolina at Chapel Hill.
Nonetheless, Molina says, " it's worth looking at this particular variable."