Job strain is known to increase the risk of a first coronary heart disease (CHD) event, but it increases the odds of further events as well, says a study reported in the Journal of the American Medical Association.
This study "is the first time that the effect of stressful work has been evaluated in a large number of men and women of various ages who have returned to work after a first heart attack," study co-author Dr. Chantal Brisson, from Universite Laval in Quebec, Canada told a leading news agency.
She added that "previous studies of people who had a heart attack mainly focused on the effect of medical factors or personal characteristics including lifestyle. The effect of the work environment has rarely been studied."
The new study, reported in the for October 10, involved 972 subjects, between 35 and 59 years of age, who returned to work after experiencing a first myocardial infarction (heart attack) and were followed for nearly 10 years. Job strain was assessed via interviews conducted at baseline (typically a few weeks after returning to work) and at 2 and 6 years.
Job strain was based on two parameters: psychological demands and decision latitude. High job strain was defined as high psychological demands and low decision latitude. The main focus was on the occurrence of CHD events in patients with and without chronic job strain, defined as high strain on the first two interviews.
Overall, 206 patients experienced the composite outcome of fatal CHD, nonfatal heart attack, or unstable angina, the report indicates.
Job strain appeared to have little impact on the risk of recurrent CHD in the first 2 years after the index event. Beyond 2 years, however, chronic job strain was associated with a 2.2-fold increased risk of recurrent events. The rates of CHD events for subjects with and without chronic strain were 6.18 and 2.81 per 100 persons per year, respectively.
Even after adjusting for 26 potential confounding factors, chronic job strain appeared to double the risk of recurrent CHD.
"These results suggest that preventive interventions aimed at reducing stressful work might prevent further complications for people returning to work after a heart attack," Dr. Brisson said.
"This means that recommendations should not focus exclusively on the individual, for example, by promoting a healthy lifestyle, but should also take into account the person's work environment. We recommend that cardiologists and occupational health services be informed of this finding in order to reduce stressful work for those returning to work after a heart attack," she added.