A heart attack occurs when the flow of oxygen-rich blood to the heart becomes suddenly blocked, preventing the heart from receiving an adequate supply of oxygen. Without prompt restoration of blood flow, the affected section of the heart muscle begins to die.
Despite regulatory efforts in many high-income countries, long working hours contribute significantly to the persistence of adverse working conditions on a global scale. According to a report from the International Labour Organization, the global prevalence of people working 48 hours and more during a week amounts close to 36%. With the transformation of modern work due to technological advances and economic globalization, an increase in workload and an extension of irregular, nonstandard forms of employment, including working from home, were reported, aggravating the control and prevention of long working hours.
Role of Long Work Hours on Cardiovascular Health
According to a study published March 29, 2021, in the Journal of the American College of Cardiology, those who work more than 55 hours per week, compared to those who work an average full-time job of 35-40 hours per week, may nearly double their risk of having a second heart attack.
Between 1995 and 1997, the Canadian researchers recruited 967 patients from 30 hospitals throughout Quebec, Canada. Patients had a history of myocardial infarction, were younger than 60 years of age, had worked in a paying job within the preceding year, and intended to return to work. Over the next six years, follow-up interviews and questionnaires were conducted.
Individual participants were classified into four categories based on their total weekly working hours:
- Part-time (21-34 hours per week)
- Full-time (35-40 hours per week)
- Low overtime (41-54 hours per week)
- Medium/high overtime (>55 hours per week)
The researchers quantified job strain as a measure of stressful work using an assessment questionnaire. Specifically, jobs defined by high psychological demand and low decision control were shown to increase the risk of incident and recurrent coronary heart disease (CHD). The level of social support was also measured both in and out of the workplace.
The study’s findings indicated that 21.5% of participants experienced a second heart attack during the study period. Additionally, working long hours was associated with a nearly doubling of the risk of developing a second heart attack. Men, as well as younger workers, were more likely to work moderate/high overtime hours (10.7% of men vs. 1.9% of women). Additionally, those with higher risk factors for chronic disease (smoking, alcohol consumption, and physical inactivity) and those with more stressful jobs were more likely to work medium/high overtime.
Reducing the Risk of A Second Heart Attack
An impressive number of prospective epidemiological studies investigated the health-adverse effects of long working hours. This recent study adds to the growing body of evidence indicating that work-related factors influence the prognosis of coronary heart disease.
The findings of this study have several significant implications for clinical practice, particularly in terms of providing more comprehensive secondary prevention measures to patients with coronary heart disease. As suggested by the authors of the Canadian study, administering a brief standardized assessment of working time and stressful working conditions to employed cardiac patients would heighten physicians’ awareness of patients’ needs and inform medical decision-making. Prevention interventions aimed at reducing these patients’ working hours may help them avoid recurrence of CHD.