Staving off Strokes

Rushing through healthy vessels, blood brings life. Clog those vessels with a clot, however, and blood brings danger and death in the form of a stroke. Chips from a massive clot in the heart break off and lodge in the brain, starving it of blood. And if that doesn’t do enough damage the first time, just wait, because another chip is likely to break off.

But early in March, researchers proposed a new way to detect these so-called cardioembolic strokes and help avoid a fatal sequel. By adding a magnetic resonance imaging scan to conventional tests, doctors can find nearly twice as many of these deadly clots, John Sheehan, a cardiac radiologist at Northwestern Memorial Hospital (Chicago Illinois) told a meeting of the Society of Interventional Radiology in Seattle, Washington.

With strokes, the problem is that in as many as half the patients we see, we can’t get a clear sense of the cause, says Steven Warach, a neurologist at the National Institute of Neurological Disorders and Stroke. Ignorance spells particular trouble in a cardioembolic stroke. With the heart pushing and pounding at the clot, it tends to be unstable, and more pieces break off, Sheehan says.

Usually a stroke patient’s heart is examined with an echocardiogram, which uses sound waves to make images. In a test of 93 patients who had both that and MRI, the MRI detected more clots and heart damages that could lead to them. Sheena doesn’t advocate replacing echo tests but rather adding MRI. If clots are detected, patients can be treated with strong anticoagulant drugs like warfarin.

But Robert Hart, and expert in cardiombolic stroke at the University of Texas Health Science Center in San Antonio, worries the study “is small, and it’s not clear that what an MRI calls a clot is really a clot.” False signals could have made the method seems better that it really was. Warach, however, says it’s a good start, and “in 10 years I wouldn’t if we’re all doing these tests.” – US News and World Report/Premium Health News Services/TMSI