(Reuters Health) - Deaths from cardiovascular disease have dropped by half in the U.S. over the past generation, but in some regions the risk of dying from some common heart ailments is twice what it is in other places, a study finds.
Nationwide, for every 100,000 people, the number of deaths from cardiovascular diseases dropped from about 507 in 1980 to roughly 253 in 2014, researchers report in JAMA.
When researchers compared mortality rates in the worst 10 percent of counties and the best 10 percent of counties, they found that differences between the two sets of counties was nearly 15 percent narrower now than it had been 35 years ago. Still, they found, large differences remained.
For example, for every 100,000 people in the counties with the highest and lowest mortality rates in 2014, the authors saw significant differences in numbers of deaths from high blood pressure (18 deaths vs 4 deaths), poor blood flow to the heart (236 deaths vs 199 deaths), and poor blood flow to the brain (68 deaths vs 40 deaths).
"We knew that there was variation between counties for coronary heart disease and stroke, but no one had every looked for the other eight important causes of heart disease that we studied," said lead study author Dr. Gregory Roth of the University of Washington School of Medicine in Seattle.
"We expected to find geographic variation, but were surprised at how large this variation actually was," Roth said by email. "Also, we found hotspots for some diseases all over the country, and often high-risk counties are adjacent to very healthy ones. Heart disease and stroke risk appears to vary dramatically almost from one freeway exit to the next."
The largest concentration of counties with high cardiovascular disease mortality extended from southeastern Oklahoma along the Mississippi River Valley to eastern Kentucky.
Several conditions were clustered substantially outside the South. For example, heart rhythm problems were more common in the Northwest, inflammation of the heart and valves was more concentrated in the Mountain West and Alaska, and enlargement of the aorta was found more in the Midwest.
The lowest cardiovascular mortality rates were found in the counties surrounding San Francisco, central Colorado, northern Nebraska, central Minnesota, northeastern Virginia, and southern Florida.
Limitations of the study include the potential for death rate estimates based on vital statistics and census data to contain errors because deaths and individuals within the population may be missed or assigned to the wrong county, the authors note.
Even so, the fact that some counties are posting much better death rates than others suggests that there's more that can be done to prevent heart disease, said Dr. David Goff, director of the Division of Cardiovascular Sciences at the National Heart, Lung, and Blood Institute in Bethesda, Maryland.
"All Americans should know that heart disease is our nation's leading cause of death, yet it is largely preventable," Goff, co-author of an accompanying editorial, said by email.
Walking just 30 minutes a day on most days, avoiding tobacco, and eating a healthy diet with mostly plants, whole grains, and less processed foods, salt and sugar can help, Goff said.
"The good news is small changes can make a difference," Goff added.