Web-Based Mindfulness Intervention in Heart Disease: A Randomized Controlled Trial

Abstract

Background: Evidence is accumulating that mindfulness training has favorable effects on psychological outcomes, but studies on physiological outcomes are limited. Patients with heart disease have a high incidence of physiological and psychological problems and may benefit from mindfulness training. Our aim was to determine the beneficial physiological and psychological effects of online mindfulness training in patients with heart disease.

Methods: The study was a pragmatic randomized controlled single-blind trial. Between June 2012 and April 2014 we randomized 324 patients (mean age 43.2 years, 53.7% male) with heart disease in a 2:1 ratio (n = 215 versus n = 109) to a 12-week online mindfulness training in addition to usual care (UC) compared to UC alone. The primary outcome was exercise capacity measured with the 6 minute walk test (6MWT). Secondary outcomes were other physiological parameters (heart rate, blood pressure, respiratory rate, and NT-proBNP), subjective health status (SF-36), perceived stress (PSS), psychological well-being (HADS), social support (PSSS12) and a composite endpoint (all-cause mortality, heart failure, symptomatic arrhythmia, cardiac surgery, and percutaneous cardiac intervention). Linear mixed models were used to evaluate differences between groups on the repeated outcome measures.

Results: Compared to UC, mindfulness showed a borderline significant improved 6MWT (effect size, meters: 13.2, 95%CI: -0.02; 26.4, p = 0.050). There was also a significant lower heart rate in favor of the mindfulness group (effect size, beats per minute: -2.8, 95%CI: -5.4;-0.2, p = 0.033). No significant differences were seen on other outcomes.

Conclusions: Mindfulness training showed positive effects on the physiological parameters exercise capacity and heart rate and it might therefore be a useful adjunct to current clinical therapy in patients with heart disease.

Trial registration: Dutch Trial Register 3453.

Conflict of interest statement

Competing Interests: The authors have declared that no competing interests exist.

Figures

Fig 1. Flowchart of mindfulness training and control group.

Fig 2. Forest plot of physiological outcomes.

All values on the left of the Y-axis indicate a difference in favour of the mindfulness group. 6MWT, six-minute walk test; IC, confidence interval, NT-proBNP, N-terminal pro-brain natriuretic peptide; * Log-transformed scores.

Fig 3. Forest plot of psychological outcomes.

All values on the left of the Y-axis indicate a difference in favour of the mindfulness group. CI, confidence interval; SF-36, Short Form Health survey; VAS, visual analogue scale; HADS, hospital anxiety and depression scale; PSS, perceived stress score; PSSS12, perceived social support.

Fig 4. Forest plot showing the Intention-to-Treat Cohen’s D results of the effectiveness of the mindfulness intervention compared with usual care on the physiological outcomes.

The width of the line indicates the 95%CI. All values lower than 0 indicate a significant difference in favour of the mindfulness group.

Fig 5. Forest plot showing the Intention-to-Treat Cohen’s D results of the effectiveness of the mindfulness intervention compared with usual care on the psychological outcomes.

The width of the line indicates the 95%CI. All values lower than 0 indicate a significant difference in favour of the mindfulness group.

Fig 6. Forest plot showing the As-Treated Cohen’s D results of the effectiveness of the mindfulness intervention compared with usual care on the physiological outcomes.

The width of the line indicates the 95%CI. All values lower than 0 indicate a significant difference in favour of the mindfulness group.

Fig 7. Forest plot showing the As-Treated Cohen’s D results of the effectiveness of the mindfulness intervention compared with usual care on the psychological outcomes.

The width of the line indicates the 95%CI. All values lower than 0 indicate a significant difference in favour of the mindfulness group.