Physical activity key to surviving heart attack, especially for socioeconomically disadvantaged patients

A new study by scientists at the Institute for Clinical Evaluative Sciences (ICES) indicates that to improve long-term outcomes of heart attack patients in Ontario, there is a need to better integrate and promote the self-management of physical activity during heart attack recovery, especially for those most socioeconomically disadvantaged.

The purpose of this study was to examine the extent to which differences in physical activity after heart attack explain long-term survival disparities between the rich and the poor.

ICES scientist and lead author David Alter says, “Patients with higher socioeconomic status experienced 80 per cent greater improvements in functional recovery, such as level of physical activity, than lower socioeconomic status patients in our study.” In fact, functional recovery (physical activity) was the strongest modifiable predictor of long-term survival after acute myocardial infarction for all patients in the study. But, he says, these differences in functional recovery were extremely important in explaining why the survival of lower SES patients was much poorer than the survival of higher SES patients after heart attack.

“Differences in improvement levels in functional recovery between high and low SES patients were not due to differences in access to medical care or referral to programs like cardiac rehabilitation, but rather were driven by an individual’s own actions outside of the healthcare system,” Alter says.

“If we want to improve the chance of survival for those who have suffered a heart attack in Ontario, we need to promote the self-management of physical activity during recovery, especially for those most socioeconomically disadvantaged.”

Prior research by ICES scientists has shown that socioeconomically advantaged Ontarians live longer after heart attacks than their disadvantaged counterparts. Previous research has explored a variety of factors (e.g., risk factors, access to medical care) that could explain differences in heart attack survival between patients of higher and lower SES. While some factors were more important than others, no study has been able to fully explain why wealthier patients lived longer after heart attacks

Accumulated evidence confirms the importance of physical activity and exercise in improving survival of heart attack patients. This was the first study to explore whether differences in functional recovery and physical activity after heart attack explained survival differences between the rich and poor.

Study highlights:

• Investigators tracked 1,368 patients who survived at least one year following an acute myocardial infarction in Ontario between 1999 and 2003 (over 9.6 years to track mortality).
• Long-term mortality rates (nearly 10 years) among the poorest, intermediate, and most affluent patients were 34.7 per cent, 26.9 per cent, and 15.2 per cent respectively.
• Differences in medical care did not account for differences in functional recovery or survival differences between the rich and poor.
• Functional recovery appeared to be self-motivated, self-initiated, and self-managed.
• Each 1 ml/kg/min improvement in fitness level (as calculated using a self-reported physical activity survey) was associated with a 9 per cent improvement in survival.
• After adjusting for physical activity recovery after heart attack, there were no significant differences in survival between the rich and poor.
• Overall, the study found that difference in functional recovery after heart attack was the strongest and most important modifiable factor that explained mortality differences across income groups.

The study “Socioeconomic status, functional recovery, and long-term mortality among patients surviving acute myocardial infarction” was published online on June 3, 2013, in the journal PLOS One.

Author block: Alter D, Ko DT, Austin PC, Lee DS, Oh PI, Stukel TA, Franklin B.

ICES is an independent, non-profit organization that uses population-based health information to produce knowledge on a broad range of healthcare issues. Our unbiased evidence provides measures of health system performance, a clearer understanding of the shifting healthcare needs of Ontarians, and a stimulus for discussion of practical solutions to optimize scarce resources. ICES knowledge is highly regarded in Canada and abroad, and is widely used by government, hospitals, planners, and practitioners to make decisions about care delivery and to develop policy.

FOR FURTHER INFORMATION PLEASE CONTACT:

• Communications, ICES
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