Context: There is evidence that job strain increases the risk of a first coronary heart disease (CHD) event. However, little is known about its association with the risk of recurrent CHD events after a first myocardial infarction (MI).
Objective: To determine whether job strain increases the risk of recurrent CHD events.
Design, setting, and patients: Prospective cohort study of 972 men and women aged 35 to 59 years who returned to work after a first MI and were then followed up between February 10, 1996, and June 22, 2005. Patients were interviewed at baseline (on average, 6 weeks after their return to work), then after 2 and 6 years subsequently. Job strain, a combination of high psychological demands and low decision latitude, was evaluated in 4 quadrants: high strain (high demands and low latitude), active (high demands and high latitude), passive (low demands and low latitude), and low strain. A chronic job strain variable was constructed based on the first 2 interviews, and patients were divided into those exposed to high strain at both interviews and those unexposed to high strain at 1 or both interviews. The survival analyses were presented separately for 2 periods: before 2.2 years and at 2.2 years and beyond.
Main outcome measure: The outcome was a composite of fatal CHD, nonfatal MI, and unstable angina.
Results: The outcome was documented in 206 patients. In the unadjusted analysis, chronic job strain was associated with recurrent CHD in the second period after 2.2 years of follow-up (hazard ratio [HR], 2.20; 95% CI, 1.32-3.66; respective event rates for patients exposed and unexposed to chronic job strain, 6.18 and 2.81 per 100 person-years). Chronic job strain remained an independent predictor of recurrent CHD in a multivariate model adjusted for 26 potentially confounding factors (HR, 2.00; 95% CI, 1.08-3.72).
Conclusion: Chronic job strain after a first MI was associated with an increased risk of recurrent CHD.