People returning to work after a first myocardial infarction (MI) were more likely to have recurrent coronary events when they worked long hours, according to a Canadian study. heart attack survivors working 55 hours or more per week had a higher risk of recurrent coronary heart disease (CHD) events (i.e., MI or unstable angina) over 6 years compared with people working 35-40 hours a week (adjusted HR 1.67, 95% CI 1.10-2.53) even after adjustment for sociodemographics, lifestyle-related risk factors, clinical risk factors, work environment factors, and personality factors. "These results showed a linear risk increase after 40 h/week and a stronger effect after the first 4 years of follow-up and when long working hours are combined with job strain," reported Xavier Trudel, PhD, of CHU de Québec-Laval University Research Centre in Quebec City, and colleagues. In their study online in the Journal of the American College of Cardiology, they suggested secondary prevention interventions to curb the number of working hours among patients at risk of CHD recurrence: For example, long working hours should be assessed routinely to improve the prognosis of post-MI patients, the team urged. Writing in an accompanying editorial, Jian Li, MD, PhD, of UCLA, and Johannes Siegrist, PhD, of Heinrich-Heine-University of Düsseldorf, Germany, agreed: A "short standardized assessment of working time and stressful working conditions among economically active cardiac patients would enrich physicians' awareness of patients' needs and inform medical decision making." "With the transformation of the modern work due to technological advances and economic globalization, an increase in work load and an extension of irregular, nonstandard forms of employment, including working from home, were reported, aggravating the control and prevention of long working hours," Li and Siegrist wrote. They urged cardiac rehabilitation programs to offer "training skills of coping with stressful demands and of strengthening resilience and relaxation" and the involvement of occupational health services in developing return-to-work plans. Workplaces with returning cardiac disease patients will need to adopt tailored, multidisciplinary programs (e.g., cognitive behavioral therapy, coaching) to boost job retention and disease management, Li and Siegrist added. The prospective cohort study included 967 MI survivors under age 60 who were recruited from 30 hospitals across Canada's Quebec province in 1995-1997. Medical records showed that 205 people had a recurrent CHD event over follow-up averaging 5.9 years. Those working the most hours after an MI tended to be men and people in their 40s and 50s. Job strain, defined as a combination of high psychological demands and low decision latitude at work, was measured using 18 items from the Job Content Questionnaire. Each person's work hours were assessed just once, at about 6 weeks after returning to work. "Some patients could have changed exposure during follow-up, leading to potential nondifferential misclassification and to an underestimation of the true effect," Trudel's group acknowledged. The observational study was also subject to potential unmeasured confounding, the researchers noted. Moreover, women (for whom previous research has linked work stress to heart risk) accounted for only about one in 10 participants, limiting the generalizability of the study's results. "In conclusion, the study by Trudel et al. provides a new piece of research evidence that work-related factors play an important role in CHD prognosis," Li and Siegrist wrote. "Occupational health services are urgently needed to be incorporated into cardiac rehabilitation programs and secondary prevention of CHD." Source
