"An experimental pill to prevent blood clots exceeded already high expectations as a better therapy for millions of people with atrial fibrillation httphealth.nytimes.comhealthguidesdiseaseatrialfibrillationflutteroverview.htmlinlinenytclassifier according to final results of a worldwide study released Sunday. The study was featured at the European Society of Cardiology in Paris and simultaneously published on the Web site of The New England Journal of Medicine http Its a remarkable achievement said Dr. Valentin Fuster a past president of American and world heart associations who was not involved with the trial. This is one of the most significant advances in cardiovascular medicine in the last five years no question Dr. Fuster chairman of federal and medical panels on atrial fibrillation and director of the heart center at Mount Sinai Medical Center in New York said in an interview. The twicedaily pill to be called Eliquis prevented  percent more strokes than the blood thinner warfarin a standard treatment for heart arrhythmia and resulted in  percent fewer incidents of major bleeding httphealth.nytimes.comhealthguidesinjurybleedingoverview.htmlinlinenytclassifier over an average of . years in the study. Eliquis also reduced total deaths by  percent a mortality benefit its makers BristolMyers Squibb and Pfizer plan to trumpet in a marketing campaign assuming the Food and Drug Administration approves the drug later this year. Barring any problems sales are quickly expected to reach billions of dollars. The new drugs are not without disadvantages. They cost much more than generic warfarin roughly  a day instead of  or less. And Eliquis and Pradaxa require two pills a day one in the morning and one in the evening instead of the oncedaily warfarin. The study included  people in  clinical sites in  countries and was consistent worldwide the sponsors said. Although the study was financed by the drug makers which raises the issue of bias it met the gold standard for medical research as a randomized doubleblinded trial in which doctors and patients did not know who took which pill until the end. The drug acts on an enzyme that leads to blood clots. Dr. Christopher B. Granger the studys lead author and a professor of medicine at Duke University said I think this is a profound trial result that will have a major impact on the practice and management of patients with atrial fibrillation. It combines both greater efficacy in terms of prevention of stroke httphealth.nytimes.comhealthguidesdiseasestrokeoverview.htmlinlinenytclassifier with a substantial reduction to bleeding risk and that package is one that will be particularly compelling. Wall Street has high expectations too. The companies stock soared after they released a brief statement http about the stroke and bleeding benefits in June. Barclays Capital said the final results on Sunday were perhaps the most anticipated R.D. event of the year. Top of Form Bottom of Form Top of Form  If everything checks out Jami Rubin of Goldman Sachs said in an interview that will confirm in our minds that Eliquis has potential to take a majority share of the  billion anticoagulation market. More than . million people have atrial fibrillation in the United States according to the Centers for Disease Control and Prevention http_statisticsfact_sheetsfs_atrial_fibrillation.htm. As many as  million people will have it by  because of an aging population with longer life expectancy. The arrhythmia in the left upper chamber of the heart can cause slow blood flow and clots raising the risk of stroke by four to six times on average the government says http_fibrillation_and_strokeatrial_fibrillation_and_stroke.htm. As many as half of people with the condition however are untreated by varying estimates. Warfarin a cheap yearold drug sold generically under the brand name Coumadin requires frequent blood tests to monitor its active level and interacts with some other drugs and foods including leafy greens. There is great appeal and demand for new drugs that do not vary so much and deliver the same strokepreventing benefits. The first new drug Pradaxa from the German drug maker Boehringer Ingelheim was introduced in the United States http last fall. In the first seven months on market about four in five cardiologists and two in five primary care doctors had prescribed it to more than  people Wael Hashad Boehringers vice president for cardiovascular marketing said in an interview last week. Pradaxa inhibits thrombin an enzyme in clot formation. Other emerging drugs block a related enzyme known as Factor Xa. Xarelto from Bayer and Johnson  Johnson approved by the F.D.A. in July http to prevent clots in hip and knee replacement httphealth.nytimes.comhealthguidessurgerykneejointreplacementoverview.htmlinlinenytclassifier surgeries goes to an F.D.A. review panel for atrial fibrillation on Sept. . Eliquis is scheduled to be submitted for F.D.A. review later this year. Its New Yorkbased makers are marketing powerhouses with the top two bestselling drugs in the world Lipitor httptopics.nytimes.comtopnewshealthdiseasesconditionsandhealthtopicslipitor_drugindex.htmlinlinenytclassifier from Pfizer and Plavix from BristolMyers Squibb. Patents on those drugs expire in the next year making Eliquis even more important to their businesses. Correction August    An article on Monday about Eliquis a new strokepreventive drug from Pfizer and BristolMyers Squibb misspelled the brand name of the drug most commonly used now for that purpose. It is Coumadin not Coumidin."