Effects of dual-task rehabilitative training in the early postoperative period after direct myocardial revascularization

Aim . To assess the effects of cognitive rehabilitation with dual-task training that involves a cognitive task combined with postural and walking control, as well as electroencephalogram indices in patients in the early postoperative period after direct myocardial revascularization. Methods . The study enrolled 48 patients scheduled for coronary artery bypass graft surgery. Subjects in this prospective, randomized study were randomized using envelopes to a postoperative cognitive training group (n = 23) and non-training group (n = 25). The cognitive training was carried out daily, starting 3-4 days after the procedure and until the discharge order. Dual tasks training (a cognitive task combined with postural and walking control) lasted 15-20 minutes. All patients were submitted to an extended neurophysiological assessment (psychometric tests and electroencephalogram study) and stabilography 3-5 days before and 8-11 days after coronary artery bypass grafting. Results. The patients who underwent cognitive training experienced postoperative cognitive dysfunction (POCD) in 39% cases in the early postoperative period after intervention, while the non-training group - in 64%. The relative risk of developing POCD in the non-training group was 2.77 (95% CI: 0.86-8.91, Z = 1.704, p = 0.08). The patients in cognitive training exhibited better cognitive state compared to the preoperative state (Z = 2.58; p = 0.01) in the absence of statistically significant differences in the non-training group. Moreover, type-1 theta power values increased in the non-training group in comparison to the preoperative values, while the cognitive training group did not have a statistically significant difference in theta power. Conclusion . Positive effects of dual task rehabilitation on the neurophysiological parameters of patients undergoing direct myocardial revascularization were demonstrated. Positive effects include lower frequency of POCD, improved cognitive state and less pronounced cortical dysfunction. The dual task training had proved a suitable training method for this category of patients. Additional studies are required to test the possibility of increasing the duration and intensity of dual task training for stronger recovery effect and improved cognitive and walking performance of patients in the postoperative period after direct myocardial revascularization.