Low Socioeconomic Status Associated With Higher Risk of Second Heart Attack or Stroke
Low socioeconomic status is associated with a higher risk of a second heart attack or stroke, according to Joel Ohm, MD, a physician at the Karolinska University Hospital and Karolinska Institute in Stockholm. The study of nearly 30,000 patients with a prior heart attack revealed that the risk of a second event was 36% lower for those in the highest income quintile, compared with the lowest, and increased by 14% in divorced patients, compared with married patients.
"Are you rich or poor? Married or divorced? That might affect your risk of a second heart attack or stroke," said Dr. Ohm. "Advances in prevention and acute treatment have increased survival after heart attack and stroke over the past several decades. The result is that more people live with cardiovascular disease in Sweden. Almost one-fifth of the total population is in this group."
Most research on cardiovascular prevention is based on healthy people, and it is unclear whether the findings apply to patients with established disease. An association between socioeconomic status in healthy individuals and future cardiovascular disease was found in the 1950s. This study investigated the link between socioeconomic status in patients who had survived a first heart attack and the risk of a second heart attack or a stroke.
The study included 29,953 patients from the Swedish nationwide registry, Secondary Prevention after Heart Intensive Care Admission (SEPHIA), who had been discharged approximately one year previously from a cardiac intensive care unit after treatment for a first myocardial infarction. Data on outcome over time and socioeconomic status (defined as disposable income, marital status, and level of education) was obtained from Statistics Sweden and the National Board of Health and Welfare.
During an average follow-up of four years, 2,405 patients (8%) had a heart attack or stroke. After adjustments for age, gender, smoking status, and the defined measures of socioeconomic status, being divorced was independently associated with a 14% greater risk of a second event, compared with being married. There was an independent and linear relationship between disposable income and the risk of a second event, with those in the highest quintile of income having a 36% lower risk than those in the lowest quintile. A higher level of education was associated with a lower risk of events, but the association was not significant after adjustment for income.
"Our study shows that in the years following a first myocardial infarction, men and women with low socioeconomic status have a higher risk of suffering another heart attack or stroke. This is a new finding and suggests that socioeconomic status should be included in risk assessment for secondary prevention after a heart attack," said Dr Ohm. "Even though health care providers are unlikely to keep track of their patients' yearly salary, simple questions about other socioeconomic variables such as marital status and educational level could make a difference."
According to the widely used assessment tools for cardiovascular risk, survivors of heart attacks are at the highest possible risk for subsequent events, regardless of other risk factors. There is, for example, no difference in the estimated risk level between a previously healthy 40-year old female from Spain and a heavily smoking, obese, elderly man with diabetes and high blood pressure from Finland.