Study Finds Newer Blood Thinner Safer

STOCKHOLM, Sweden – In the largest study ever conducted on people in the throes of a heart attack, scientists have found that giving a newer blood thinner instead of the traditional one could halve the risk of causing life threatening bleeding.

Researchers who presented their findings Monday at the annual conference of the European Society of Cardiology, said that switching to the new drug could prevent 10 fatal heart attacks, four strokes and 25 major bleeding incidents for every 1,000 people receiving treatment.

When patients come into the emergency room with a condition known as acute coronary syndrome, where there is a sudden serious reduction in blood flow to the heart, they are treated with an arsenal of drugs aimed at preventing blood clots that cause heart attacks. The medications work by blocking several different points in the clot-forming process.

The drugs are very effective, but the trade-off is that they increase the risk of bleeding. Major bleeding is now the biggest threat that these patients face.

The study, which involved 20,000 patients being treated in hospitals in 41 countries, swapped one of those drugs in the basket for a newer one that blocks clotting in a very similar, but not exactly the same, way.

“The future really is to find therapies that are just as effective, but safer,” said the study’s leader Dr. Salim Yusuf, cardiology chief at McMaster University in Hamilton, Ontario, Canada.

Half the patients were given the traditional injection, enoxaparin, while the other half were given the newer one, Arixtra.

The two drugs were equally effective at preventing death, heart attack and recurrence of the blockage of blood flow to the heart in the first 10 days, the most vulnerable period. However, while 4 percent of patients getting the traditional drug developed severe bleeding, only 2 percent of those getting the new drug did.

Within that category of major bleeding, there were dramatic reductions in the number of bleeds that needed surgery to stop them and in the bleeds that required a blood transfusion.

Dr. Peter Weissberg, medical director of the British Heart Foundation, which was not involved with the research, said the strategy offers an important refinement in the quest to balance the need to prevent clots with the need to prevent bleeding.

Heart surgeon Dr. Timothy Gardner, an American Heart Association spokesman who was not connected with the research, said the findings provide “compelling reasons” to switch to the new drug because the study tested it across widely different health systems and came up with a consistent result. He said the findings could have a tremendous impact.

Yusuf said the prevention of bleeding is a life saver because major bleeding increases the risk of death by over 400 percent.

The study showed that 30 days after the treatment, there were 17 percent fewer deaths in the group that got the newer drug than in the other group.

“This means a short-term therapy that is just as effective at preventing events but is much safer translates in the long term to an important difference,” Yusuf said.

The drug, which is already used to prevent a type of blood clot in the legs known as deep vein thrombosis, is cheaper than standard treatment, Yusuf said.

The study was paid for by the makers of the drugs.