[본문]
New Blood Thinners Will Prevent Blood Clots Without Causing Bleeding A new class of anticoagulant drugs on the horizon is taking fresh aim at one of cardiology’s toughest challenges: how to prevent blood clots that cause heart attacks and strokes, without leaving patients at risk of bleeding. The challenge is this: The body generates two types of clots—good ones that plug holes in blood vessels to stop bleeding caused by external injuries, and bad ones that grow inside arteries and veins. These can block blood flow to critical organs, potentially leading to injury or death. For decades, drugs developed to prevent the bad clots have targeted proteins involved in forming both types of clots. As a result, preventing clots often comes at the price of a higher risk of bleeding, causing many patients to refuse to take, or stop taking, the medicine. Factor XI, it turns out, is crucial for the formation of the bad clots inside blood vessels, what doctors call thrombosis. But researchers now believe that factor XI, unlike other blood factors, plays a minimal role in forming the good clots that stop bleeding. That suggests drugs against it could prevent the bad clots without significantly disrupting the process that causes good clots, and thus minimize excess bleeding associated with anticoagulants and other blood thinners. Important questions about the effectiveness of factor XI inhibitors have yet to be answered, and success isn’t ensured. Several large-scale or Phase 3 clinical trials are now under way to determine the clinical and economic potential of the new agents. Results are expected later this decade.