Researchers have found that a two-pronged approach to cholesterol management -- using one medication to boost the good cholesterol and another to lower the bad -- is more effective at slowing the progression of heart disease than one drug alone.A new study says that adding extended-release niacin, a member of the vitamin B family, to cholesterol-lowering statins slowed the progression of atherosclerosis, or the dangerous buildup of plaque in the arteries. The findings may signal a shift in the focus of current treatment.This study, the first to look at such a combination therapy, was reported Wednesday at the American Heart Association’s scientific sessions in New Orleans and will appear in the association journal Circulation.