Blood thinner may be biggest medical advance since aspirin

"This is a breakthrough," said Dr. Valentin Fuster of Mount Sinai School of Medicine in New York. "It will change the practice of medicine."

Some 2 million Americans are hospitalized with mild heart attacks and bad chest pain annually. Experts said the drug's impact will be even greater if it becomes routine treatment for the additional 1 million Americans who have full-blown heart attacks.

"Everyone will be put on this," said Dr. Christopher Cannon of Brigham and Women's Hospital in Boston. "It's relatively cheap and has monster benefits. This is what we have all been waiting for."

Heart attack patients are already routinely sent home with aspirin, beta blockers, ACE inhibitors and cholesterol-lowering drugs.

Currently, Plavix, which was introduced in 1998, is given primarily to prevent dangerous blood clots after balloon angioplasty. But doctors say it will soon become a regular pill for many more heart patients.

The study, which was directed by Dr. Salim Yusuf of McMaster University in Hamilton, Ontario, was presented at a meeting in Orlando of the American College of Cardiology. The study was financed by Plavix's makers, Sanofi-Synthelabo and Bristol-Myers Squibb.

The study was conducted on 12,562 patients at 482 hospitals in 28 countries. All victims had what doctors call acute coronary syndrome. This is either mild heart attacks -- known technically as non-Q-wave attacks because of their appearance on electrocardiograms -- or unstable angina, which is chest pain that is especially severe or unpredictable.

All patients got their standard treatments, including aspirin, which has a similar effect as Plavix on the clotting cells called platelets. They were randomly assigned to get either daily Plavix or dummy pills within a day of their symptoms and stayed on the drug for periods ranging from three months to a year.

Doctors began to notice a benefit of the drug within the first two hours of treatment. <