A large new study found that a blood-thinning drug (search) already available in Europe and Asia improves the chances of surviving a heart attack, while a simple, sugar-based solution that once looked promising does nothing to help victims.

The mixed results involve two low-tech treatments that researchers have hoped could help ease the global burden of heart attacks, which kill more than 7 million people worldwide each year — at least half of them in developing countries.

The research was conducted on more than 20,000 people in India, China and Latin America.

Patients on the blood thinner reviparin (search) had a 13 percent lower risk of dying, having another heart attack or having a stroke within 30 days after being stricken, compared with patients given injections of dummy medication.

The drug is used in Europe and parts of Asia to prevent and treat blood clots but not heart attacks. It is not approved for use in North America.

Co-author Dr. Shamir Mehta of McMaster University called the findings a significant advance and said no clot-fighting drug since aspirin has shown it can reduce deaths from heart attacks.

The news was disappointing for the sugar-based infusion, studied since the early 1960s as a possible method for keeping heart muscle tissue alive during a heart attack. The infusion includes glucose, insulin and potassium and is designed to provide fuel for the heart when a clot cuts off blood flow.

"Anybody can make it up ... anywhere in the world," Mehta said. "That's why this would have been such a big deal" if it had worked.

The study compared rates of death, cardiac arrest and recurrent heart attack 30 days after the initial attack in patients who received the intravenous infusion for 24 hours and in those who did not. There were no significant differences in outcomes in the two groups.

Some less rigorous studies of the sugar-based infusion have shown positive results. An accompanying editorial suggested it is time to abandon research into that approach.

The research appears in Wednesday's Journal of the American Medical Association.

Dr. Sidney Smith, an American Heart Association spokesman, said the research shows reviparin works "in countries where the resources are limited and where the epidemic is growing."

"There's a very strong need for therapies that are known to work that can be used by large numbers of people," Smith said.

He said the treatment appears promising but not conclusive for heart attack patients in the United States, who — unlike most of the patients in the study — frequently undergo angioplasty to open blocked arteries.

The studies received no pharmaceutical company funding.

North Chicago, Ill.-based Abbott Laboratories Inc. acquired reviparin's European manufacturer, Knoll Pharmaceuticals, during the 2001-04 research. A company spokeswoman declined to discuss whether Abbott plans to seek U.S. approval for the drug.