On the horizon
On the horizon
Can a device replace warfarin? In a heart beset by atrial fibrillation, blood clots can develop in the heart's upper chambers (the atria). Most of them form in the left atrial appendage, a thumblike pocket in the left atrium. Closing off this pocket with surgery or a fabric-covered cage could offer an alternative to the blood thinner warfarin (Coumadin, Jantoven, generic). Small trials suggest that these approaches can keep stroke-causing clots from entering the circulation, but questions about how well they stack up against warfarin for safety and effectiveness must be answered by ongoing trials.
Lasers for stroke. Sending laser beams into the brain could someday help lessen the impact of a stroke. The most effective treatment for stroke today, a clot-busting drug called tissue plasminogen activator, must be given within three hours of the start of a stroke. Researchers are testing transcranial laser therapy as late as 24 hours after a stroke has begun. Here's how it works: after having his or her hair shaved off, a stroke victim is fitted with a special cap that directs laser beams into the brain. The light waves are thought to rev up the metabolism of oxygen-deprived brain cells and keep them alive until the blockage causing the stroke shrinks or disappears. The results of early trials are mixed.
Disappearing heart stents. Wire-mesh stents are routinely used to prop open a narrowed or blocked coronary artery after it has been opened by balloon angioplasty. The earliest stents, made of bare metal, often triggered a wild regrowth of cells lining the artery, causing it to narrow again. Stents now in use carry medication that is released slowly, which prevents this overgrowth. The drawback is that blood clots sometimes form on these drug-eluting stents, necessitating the long-term use of aspirin and clopidogrel (Plavix). Researchers are working on the next generation — a stent that stabilizes and reshapes the artery, then slowly dissolves. Two-year results from an ongoing trial give good grades to a bioabsorbable stent. Although no such stent is yet on the market, the promising results will probably spur stent makers to begin seeking FDA approval.