Between 1980 and 2014, the number of Americans dying from cardiovascular disease was cut in half. Though cardiovascular disease — an umbrella term for conditions that affect the heart and circulatory system, commonly known as heart disease — remains the most common cause of death in the U.S. by a wide margin, the drop in deaths shows significant progress. This nationwide trend, however, obscures the fact that not every region has made such headway. A new analysis shows that different types of cardiovascular disease have much higher mortality rates in some parts of the country than others.

In April, we published an interactive map showing 35 years of estimated mortality rates in every county in the U.S. for 21 causes of death. The organization that produced these estimates, the Institute for Health Metrics and Evaluation, started with broad categories — such as cancer and neurological disorders — but has since begun drilling down to more specific causes. Last month the institute released its estimates of mortality rates for 12 categories of cardiovascular disease. We’ve updated our interactive map with the new data.

35 Years Of American Death: Our maps show estimated mortality rates for leading causes of death for every county in the U.S. going back to 1980. They’ve been updated with specific types of cardiovascular disease. Read more »

And that data reveals that the “historic public health success” of lowering death rates from heart disease has not been realized in many parts of the country, said Dr. Gregory Roth, a cardiologist and an author of the paper summarizing the institute’s latest findings. “We know what causes cardiovascular diseases and how to prevent it in general,” Roth said, “but not in a particular location.”

The reason for such local and regional variation could be tied to differences in income and access to health care, said Dr. Erica Spatz, a cardiologist and researcher at Yale University’s Center for Outcomes Research and Evaluation. “It is hard to access and afford healthy food and have time for exercise,” she said. “It takes dedication to be healthy, and it’s a luxury.”

These geographic trends also vary from disease to disease within the overarching category of cardiovascular disease. The Southeast, for instance, has higher rates of rheumatic heart disease, hypertensive heart disease and hemorrhagic stroke.

Beyond the Southeast, which is widely known to suffer from higher rates of cardiovascular diseases and other health problems, mortality rates are higher in the Northwest for atrial fibrillation and flutter, and the Rocky Mountain region experiences higher rates of death by endocarditis.

Roth says that identifying these patterns is only the first step in a long process to improve outcomes. Researchers and physicians are still working on how local communities can better keep people healthy. When those local solutions are found, perhaps the overall trend of fewer deaths from cardiovascular diseases will be found in every part of the U.S.

Explore the data yourself here.

CORRECTION (June 19, 1 p.m.): An earlier version of a map in this article was incorrectly labeled as the map for hemorrhagic stroke; it shows the data for endocarditis. The label has been corrected.