Although heart attack death has declined across all regions of the United States, it is proportionately higher in the South, possibly related to the uneven distribution of socioeconomic and traditional cardiovascular risk factors, according to research presented at the American College of Cardiology's 63rd Annual Scientific Session.

While rates of cardiovascular disease vary by state and region of the country, little is known about geographic variation in associated death rates. In the first retrospective study to examine heart attack in-hospital mortality by region, researchers used the Nationwide Inpatient Sample (NIS) to identify more than 12.9 million heart attack cases from 2000 to 2010. They investigated the trends in in-hospital deaths, risk factors and procedures performed in different regions of the country.

Researchers found a decline in heart attack death in all regions of the United States over this time span. However, the overall in-hospital death rate per 100,000 cases was highest in the South followed by the Midwest, Northeast, with the least occurring in the West. There was a significant discrepancy in heart attack deaths among African-Americans and Hispanics in the South compared to whites in the region (a 50 percent and 15 percent relative higher risk, respectively). The analysis also showed a significantly higher occurrence of cardiovascular risk factors including diabetes, obesity, high blood pressure, high cholesterol and smoking in the southern states compared to other regions. Median household income was also much lower in this area.

"We've made great strides in the way we treat our heart disease patients in this country, especially with [advances in] new medication, technologies and treatment protocols, but a gap of this size is unacceptable," said Sadip Pant, M.D., an internist with the University of Arkansas for Medical Sciences, and lead investigator of the study.

While the researchers did not seek to establish cause and effect, they speculate the disparity may be due to lifestyle factors and access to health care. The higher prevalence of risk factors like obesity, diabetes and high blood pressure most likely reflects the unhealthy lifestyle, dietary habits and lack of exercise among people in the region, Pant said.

"Lower household income in the region may play a role by affecting the type of care people receive, how well they are able to manage their risk factors, how often they see their doctors, and whether they have access to the proper medications," he said.

Pant hopes the study will raise awareness and drive efforts to develop a system to better serve heart patients in the South. The next steps for research will be to examine the number of procedures performed in each geographic region and how this affects the cost of care related to hospitalization due to heart attack.