Since the 1940s, heart disease has held a dubious distinction as the leading cause of death in the United States, with cancer consistently placing second in terms of overall mortality.

But due to a sharp decrease in deaths resulting from cardiovascular disease, cancer has narrowed the gap and is challenging for the title of the nation’s number-one cause of mortality, according to research published online by the American Heart Association.

Researchers from Brigham Young University in Provo, Utah, set out to investigate whether cancer’s transition from runner-up to leading cause of death had already begun to take place around the country. They analyzed state-specific mortality data from the U.S. National Vital Statistics System and determined mortality rate ratios of heart disease and cancer for each state from 1999 to 2013 on an annual basis.

The found that during that time period, mortality as a result of heart disease fell from a rate of 266 to 193 per 100,000 nationwide, while national cancer mortality fell from 201 to 185 per 100,000, resulting in a total heart disease/cancer mortality rate ration decrease from 1.32 to 1.04.

Many states saw cancer overtake heart disease as the leading cause of death over the same 14-year period, however, with the transition taking place in 22 states since 1999.

“Due to rapidly declining [heart disease] mortality rates, the transition from [heart disease] to cancer as the leading cause of death has already occurred in nearly half of U.S. states,” the researchers wrote. “National-level data mask this reality, implying an oversimplified public health message that ‘[heart disease] is the leading cause of death.’ State-specific data highlight successes in CVD prevention and control and the need for further improvements in cancer prevention and control.”