Adjusting Work Intensity for Returning Heart Patients May Prevent Mental Health Conditions

Nancy Grover

Sarasota, FL ( – Mental health problems – not physical issues – may impede returning to work for some heart patients. A new study suggests workers who undergo non-invasive treatments for heart problems don’t fare well if their subsequent workload exceeds their exercise tolerance.

“Patients whose work intensity was higher than their exercise tolerance had worsened anxiety and depression scores at the three months post-discharge examination,” researchers wrote in the Journal of Occupational and Environmental Medicine. “Although it is difficult for them to adjust the intensity of their work, it is necessary to provide detailed information and recommendations from hospital medical staff and occupational health professionals to prevent mental health problems.”

The researchers studied Japanese workers with first-time heart issues and found that simple steps by providers and employers could prevent unnecessary behavioral health obstacles to their returns to the workforce.

The Study

Heart disease is among the leading causes of death throughout the world, and the rate is expected to increase. Metabolic syndrome, a cluster of conditions occurring simultaneously, is rising among the working population, according to previous research. Higher blood pressure, high blood sugar, excess body fat around the waist and abnormal cholesterol or triglyceride levels can result in heart disease, which leads to a decline in physical function and mental health.

Studies have indicated workers who return after the onset of heart disease may be at increased risk of mental health problems. Depression in these patients has been reported to be a predictive factor for RTW. Researchers conducted a study to assess the relationship between return to work (RTW) status and changes in mental health, three months after hospital discharge.

A total of 26 patients who had non-surgical heart disease were included in the study, comprised of 18 with ischemic heart disease and 8 with heart failure. All had been enrolled at admission for cardiac rehabilitation (CR) between September 2014 and March 2019. CR in Japan is described as a multifaceted, comprehensive program that takes place after the onset of heart disease and continues through hospital discharge. The goal is to improve the physical and psychological health of the patient, along with occupational status.

The researchers hypothesized that when heart patients return to work, exercise tolerance might not be factored in. “Additionally, the intensity of their work may affect their mental health, leave of absence, and loss of employment,” they wrote.

They used various measures to evaluate the types and frequencies of applied activities in daily life and collected the information through interviews or mailed questionnaires.

Mental health was assessed via the Hospital Anxiety and Depression Scale (HADS), a self-reported measure including 14 items that results in a summary score and two subscale scores – for anxiety and depression. Three months after hospital discharge, the participants were sent a questionnaire about their mental health and status of RTW, leave of absence, and loss of employment.

For each patient the researchers looked at the anaerobic threshold (AT), considered an indicator of safe exercise with low physical stress for patients with heart disease. Workload strength refers to the metabolic equivalents (METs) table of physical activity, which is one way exercise physiologists estimate the number of calories burned during physical activity. The participants were asked about the workload strength of their jobs. They were then split into two groups.

“The relationship between exercise tolerance of the participant and work intensity of the job was defined as ‘reasonable workload (RW)’ when the assessed work intensity did not exceed AT METs, and ‘over workload (OW)’ when it exceeded AT METs,” they wrote. “Then, the patients were allocated to either the RW or OW group.”


Physical function “was significantly different” for members of the two groups. Those in the RW group had mean AT METs of 3.4 and peak METs of 4.7; however those in the OW group had AT METs of 2.8 and peak of just 3.8.

In terms of the activities of their jobs, there were also substantial differences. In the RW group 11 patients were sedentary while four were mainly active. In the OW group just two were sedentary and 9 were mainly active.

Workers whose work intensity was higher than what they could tolerate for exercise fared worse in terms of their mental health.

“RTW after three months was higher in the RW group (100%) than in the OW group (63.6%),” the study said. “Mental health in the OW group significantly deteriorated compared to baseline and was higher than that in the RW group.”

Anxiety scores for those in the RW group did not change from baseline to three months after discharge. However, those in the OW group had higher scores, resulting in what the authors said was “a significant difference.”

In terms of depression, those in the RW group actually had decreased scores three months after hospital discharge. Those in the OW group had increased scores.

The mental health differences likely explain the RTW status of the workers after three months. All 15 patients in the RW group were at work; however just 7 from the OW group had returned “showing a significant difference between the two groups,” the authors wrote. “All patients who had been suspended from office or lost employment were in the OW group.”

The findings could help prevent mental health deterioration among workers who return after heart problems. Providing information on the physical capacity of each worker would be a start. Additionally, workers whose exercise tolerance is lower than their work intensity could be helped through continuing exercise therapy.

“Our survey presented a novel finding by demonstrating the relationship between exercise tolerance and mental health from the time of hospitalization to after RTW,” the researchers wrote. “Therefore, it might be necessary to assess exercise tolerance and adjust work intensity in cardiac patients to facilitate RTW and appropriate transfer or job change without exacerbating their mental health issues.”