Stress appears to be a strong predictor of health-related quality of life (HRQoL) in patients with coronary heart disease (CHD) undergoing cardiac rehabilitation, according to a poster presented at the recent Singapore Prevention & Cardiac Rehabilitation Symposium 2017 (SPCRS 2017).

Researchers from the Division of Psychology, Nanyang Technological University, Singapore, and the Singapore Heart Foundation assessed the study participants who were 203 individuals aged ≥21 years with CHD who were undergoing cardiac rehabilitation at the Singapore Heart Foundation (mean age 62.8 years, 80.5 percent male). Individuals with serious comorbid conditions or cognitive defects that limited their ability to respond to survey questions were excluded from the study.

Participants were assessed using the MacNew Heart Disease Health-Related Quality of Life Questionnaire (MacNew), Six-Minute Walk Test (6MWT), Perceived Stress Scale (PSS-10), the International Physical Activity Questionnaire (IPAC), and the Cardiac Self-Efficacy Questionnaire and Heart Failure Self-Efficacy Scale.

The study was conducted based on the hypothesis that physical activity and self-efficacy moderated the relationship between stress and CHD outcomes, where during periods of high stress, individuals who were physically active or self-efficacious would experience less severe adverse CHD health outcomes.

The results showed that participants did not experience much stress and were generally self-efficacious.

There was a significant association between stress and self-efficacy on emotional HRQoL (β=0.167; p<0.01). Higher stress levels were associated with lower emotional HRQoL, particularly at lower levels of self-efficacy (β=-1.15; p<0.01), and less so at higher self-efficacy levels (β=-0.77; p<0.01). [SPCRS 2017, poster S-100]

In contrast, the association between stress and self-efficacy on physical HRQoL was insignificant, as was the impact of stress on 6MWork, and physical activity on CHD health outcomes.

“Self-efficacy moderated the effects of stress on emotional but not physical HRQoL,” said the researchers.

One of the reasons cited for this finding was that self-care could have mediated the relationship between self-efficacy and physical but not emotional HRQoL. It was also possible that median physical HRQoL was high and that none of the participants reported low physical HRQoL, thus limiting the ability of self-efficacy to improve physical HRQoL during times of stress, said the researchers.

“Enhancing cardiac self-efficacy may ameliorate the detrimental impact of stress on mental health functioning among recovering CHD patients in rehabilitation,” said the researchers.