A study finds heart patients who get beta blocker drugs before bypass surgery do better. The study says these patients have slightly better survival rates and fewer complications. Beta blockers slow the heart rate. The study found 2.8 percent of patients on beta blockers died within 30 days after surgery. Three-point-four percent of patients who were not on the drugs died in that period. Beta blocker patients also were slightly less likely to have complications such as strokes , additional surgery and kidney failure. The lead author is at Louisiana State University. The study is in the Journal of the American Medical Association.