The Effect of Mindfulness-Based Stress Reduction on Anxiety and Stress in Patients with Coronary Heart Disease after Coronary Artery Bypass Graft Surgery: A Single-Subject Study

*Correspondence: Rasoul Heshmati, Department of Psychology, Faculty of Educational Sciences and Psychology, Tabriz University, Tabriz, Iran psy.heshmati@gmail. com Abstract Background and objectives: Coronary artery disease (CAD) is associated with negative emotions of anger and stress, which are one of the nonclinical risk factors of the disease. Therefore, evaluation of the effective therapeutic models alleviating the patients’ negative emotions is of paramount importance. This study aimed to examine the effect of mindfulness-based stress reduction (MBSR) on anger and stress in patients with coronary heart disease after coronary artery bypass graft (CABG). Methods: This research had an A-B single-subject design. The research population encompassed all patients with coronary heart disease referring to Shahid Madani Hospital of Tabriz, Iran during the second half of 2016 for rehabilitation measures. Four patients were selected using convenience sampling. Before the interventions, the participants completed state-trait anger expression inventory (STAXI-2, Spielberger) and depression anxiety stress scale (DASS) throughout two consecutive weeks, which led to establishing two baselines. Afterwards, they received mindfulness-based stress reduction training during seven consecutive weeks and completed the questionnaires after each intervention. Percentage of recovery, percentage of non-overlapping data (PND), standard mean difference (SMD), and effect size were used to analyze the data, and eye diagram analysis was adopted to interpret the data. Results: The findings indicated that the mean recovery rate for all participants was 0.84 and its effect size index was 2.7. Moreover, the mean percentage of recovery and the effect size index of mindfulness intervention on the patients’ anger were 0.18 and 1.38, respectively. Conclusion: According to the results of the study, it could be concluded that mindfulness-based stress reduction is an effective intervention to regulate stress in patients suffering from coronary heart disease.