The percentage of people with heart disease in the United States has dropped, according to the Centers for Disease and Control Prevention.

Overall, 6 percent of adults had heart disease in 2010, a decline from 6.7 percent in 2006, said the CDC in its Weekly Moratility and Morbidity report.

However, the study said that the rates of heart disease vary greatly by state, race, sex and educational levels. For instance, less educated people and those living in southern states such as Kentucky and West Virginia, still have heart disease rates above the national average, the CDC said.

The study found that young people, women, Asians, Native Hawaiians and college graduates showed the biggest declines.