Geographic variability of CVD burden in US may end long-term CVD decline

Although the burden of cardiovascular disease (CVD) in the United States has improved for all states between 1990 and 2016, the rate of decline varies widely and is strongly associated with socioeconomic level, according to researchers representing the Global Burden of Cardiovascular Diseases Collaboration.

In addition, they found that the burden of CVD varies by geography, with southern states having the largest. Further, the increasing burden of CVD in some states parallels an increase in all-cause mortality for certain regions and subgroups of populations in the US.

“Our finding of increasing CVD burden is concerning and suggests that long-term decline in CVD may be ending,” they wrote in JAMA Cardiology, where their report is published. “New clinical or public health interventions delivered earlier in the life course may be required to alter this alarming trajectory.”

States with the largest burden of CVD took 25 years to achieve levels observed among the healthiest states in 1990.

“States with the highest burden of CVD in 1990, such as Kentucky, West Virginia, Alabama, Arkansas, Louisiana, Tennessee, and Oklahoma, are only now achieving the 1990 levels of CVD burden in Massachusetts, Connecticut, and New Jersey,” according to the report.

CVD accounted for more than 900,000 deaths in the US in 2016, but mortality from CVD is no longer improving, the investigators note. They used death certificate data obtained from the National Center for Health Statistics in each state to produce estimates of CVD burden. All-cause, all-cardiovascular, and cause-specific mortality were estimated using the Cause of Death Ensemble Model.

From the number of fatal and nonfatal episodes, researchers calculated the CVD disability-adjusted life-year (DALY) for each state.

The age-standardized rate of CVD DALYs decreased significantly in all states between 1990 and 2016, with wide regional variation in the amount of the decline. The states that had the slowest decline in CVD burden according to their CVD DALYs were Arkansas, Oklahoma, Alabama, Kentucky, Missouri, Indiana, Kansas, Alaska, and Iowa. The largest declines in DALYs occurred in the District of Columbia, New Hampshire, and New York.

Researchers also found that in all states, the rate of decline was slower for women than men. The slowest decline was observed for women in Oklahoma, Arkansas, and Alabama. Total CVD burden increased for both men and women from 2010 to 2016 in Indiana, Kentucky, Michigan, Mississippi, Missouri, New Mexico, and South Dakota.

The greatest age-standardized CVD burden was concentrated in a band of states extending from the Gulf Coast to West Virginia. The highest rate of CVD DALYs was in Mississippi followed by Arkansas, Oklahoma, Louisiana, Alabama, Tennessee, Kentucky, West Virginia, South Carolina, and Georgia. Several states including Indiana, Missouri, Ohio, Michigan, North Carolina, Nevada, and Texas had levels of CVD DALYs nearly as high, the authors pointed out.

The lowest absolute rate of CVD DALYs was in Minnesota followed by Colorado and areas of New England and the Pacific Northwest.

More than 80% of CVD burden could be attributed to known modifiable risk factors.

“The prevention of CVD through the reduction of these well-known risk factors remains a major public health goal for the United States,” the authors wrote.

In 2016, “CVD as a proportion of all DALYs increased with age rapidly after age 40 years, rising to account for 20% of all DALY burden by age 65 years,” according to the data.

Other findings from the analysis include the following:

• Ischemic stroke increased rapidly as a cause of CVD after age 60.
• Ischemic heart disease was the dominant source of CVD DALYs after age 40.
• In those aged 65 years and older, atrial fibrillation became an increasingly common cause of CVD burden.
• New York had the greatest age-standardized prevalence rate for heart failure in 2016 followed by Indiana, Oklahoma, Kentucky, Michigan, West Virginia, and Ohio.
• Minnesota, Washington, Vermont, and Iowa had the lowest prevalence of heart failure.
• Dietary risk factors accounted for the greatest proportion of age-standardized CVD DALYs for all states, followed by high systolic blood pressure, high body mass index, high total cholesterol level, high fasting plasma glucose level, tobacco smoking, and low levels of physical activity.
• Socioeconomic status could not fully explain a population’s level of CVD burden or risk factors.

In an editorial accompanying the analysis, Wayne D. Rosamond, PhD, MS, from the University of North Carolina at Chapel Hill, wrote that the study “provides several key additions to our current understanding of the role of location in cardiovascular health and generates important new questions.”

Dr. Rosamond noted that several of the states where the decline in CVD burden is slowing or the CVD burden is even increasing have fewer inhabitants reporting cardiovascular metrics within the ideal range.

Dr. Rosamond called the statistic that 80% of CVD burden could be attributed to known modifiable risk factors “a potentially encouraging finding if we are to prevent the reversal of the decline in CVD burden across the United States.”

The reason behind the slower CVD burden decline in women is a question for future research, he added.

The Institute for Health Metrics and Evaluation received funding from the Bill and Melinda Gates Foundation.