Competition among hospitals and cardiology groups is the most common barrier to implementing systems for treatment of heart patients, U.S. researchers say. Lead author Dr. James G. Jollis, professor of medicine at Duke University Medical Center in Durham, N.C., and colleagues said 381 systems that treat ST-segment elevation myocardial infarction -- the most severe form of heart attack -- responded to the Mission: Lifeline survey, conducted from April 2008 to January 2010. Nearly 300,000 people a year suffer such an attack, which occurs when a blood clot completely blocks an artery to the heart. To prevent death, it\'s critical to restore blood flow immediately, either by surgically opening the blocked vessel or by giving clot-busting medication, Jollis said. \"It\'s essential to get competing hospitals and separate EMS agencies within a community to work as a team to provide optimal care for heart attack patients,\" Jollis said in a statement. \"These study findings can serve as a benchmark and lessons learned as additional communities across the country create their own systems of coordinated, integrated, evidence-based care for STEMI patients.\" The systems that participated in the survey represented 899 hospitals in 47 states.