County-Level Data Reveals Disparities in Cardiac Death Rates

An analysis of county-level data revealed progress in reducing premature cardiac deaths in began to decline in 2011, with significant disparities among counties, according to research published in the Journal of the American Heart Association.

In 2012, all United Nations-member countries including the US committed to achieving a 25 percent reduction in premature death from cardiovascular diseases, cancer, diabetes, or chronic respiratory diseases by 2025.

Additionally, the Global Cardiovascular Disease Taskforce, which includes the American Heart Association, American College of Cardiology Foundation, and other organizations set a goal to reduce premature deaths from cardiovascular diseases and stroke.

Researchers in China and the US accessed multiple databases to analyze county-by-county data on nearly 1.6 million premature cardiac deaths in the US that occurred between 1999 and 2017 among individuals between 35 and 74 years of age.

The results showed that while rates declined between 1999 and 2017, since 2010 the pace of the decline has slowed significantly.

Additionally, of nearly 1.6 million premature cardiac deaths from 1999 to 2017, about 61 percent occurred outside of a hospital. The findings also revealed that while overall premature cardiac death rates fell, the proportion of out-of-hospital deaths rose from 58.3 percent to 61.5 percent in 2017.

Researchers found that twice as many premature cardiac deaths occurred in men compared to women, and premature death rates were 3.4 times higher among African Americans than Asians or Pacific Islanders.

“From the 1960s to 2010s, the United States experienced remarkable decline in cardiovascular disease mortality that was coined as one of the major public health accomplishments of the 20th century,” said lead investigator Zhi-Jie Zheng, MD, PhD, a University Endowed Distinguished Professor and chair of the department of global health at Peking University in Beijing, China.

“Increasing numbers of out-of-hospital deaths and fatal heart attacks in younger age groups, coupled with a steady widening of disparity of socioeconomic and health environment factors affecting health care at the county level, appear to be the key drivers of the slowdown we have seen since 2010.”

Disparities were largely associated with demographic composition and socioeconomic status. Demographic composition, which included population size, rural living, sex, age, racial/ethnic, and foreign-born as factors, accounted for just over a third of out-of-hospital and in-hospital premature cardiac deaths.

Differences in socioeconomic factors, which included median household income, unemployment, school enrollment, and number of violent crimes per 100,000 population, accounted for about 20 percent of deaths.

Healthcare environment, which included density of primary care physicians; diabetic, Medicare enrollees who had diabetes confirmed by an HbA1c test; access to places for physical activity; and access to health foods accounted for 18.6 percent of out-of-hospital and 13.9 percent of in-hospital deaths.

While population health status, which included scoring according to the cardiovascular disease risk index derived from a set of major cardiovascular risk factors, self-rated poor/fair health, and total Medicare reimbursements per enrollee accounted for 23.7 percent of out-of-hospital deaths and 30.2 percent of in-hospital deaths.

These results indicate that county-level disparities in cardiovascular death rates are mainly due to socioeconomic factors and the social determinants of health.

“Our findings suggest a need for health care policy changes and programs that can identify high-risk, young populations prone to premature cardiac death and support improved cardiac health,” Zheng said.

The study highlights the need for public policies that aim to diminish disparities and improve overall health.

“The decline in the reduction of premature deaths attributable to heart disease is disheartening and is an urgent call to action,” said American Heart Association President Mitchell S. V. Elkind, MD, MS, FAHA, FAAN, professor of neurology and epidemiology at Columbia University New York and attending neurologist at Columbia University Irving Medical Center of the NewYork-Presbyterian Hospital. 

“We must invest and focus public and private efforts to address the disparities in risk factors, access to care and other factors slowing the progress in heart disease so that we can increase the opportunity for all Americans to live longer and healthier lives.”

The study’s limitations included potential errors in the reporting of cause of death, which is reliant on county-level data, government health data. However, researchers expect that the results will facilitate improved interventions and promote healthier behaviors.

“Heart attacks can occur at any age, not just in older persons,” Zheng said. “The slower decline in out-of-hospital rates is alarming and warrants more precision targeting and sustained efforts to integrate lifestyle and behavioral interventions that increase heart health and reduce the risk of premature cardiac death.”