RESEARCH REPORT PLATFORM PRESENTATION

PHYSIOTHERAPY SUPERVISED WALKING PROGRAM IMMEDIATELY FOLLOWING CABG RESULTS IN EARLIER RETURN OF FUNCTIONAL CAPACITY. A RANDOMIZED CONTROLLED TRIAL. Hirschhorn A^1,3, Richards D², Mungovan S¹, Morris N³, Adams L³; ¹Westmead Private Physiotherapy Services, Westmead Private Hospital, Sydney, Australia. ²Westmead Private Cardiology, Westmead Private Hospital, Sydney, Australia. ³School of Physiotherapy and Exercise Science, Griffith University, Gold Coast, Australia

PURPOSE: We aimed to investigate whether a moderate intensity walking exercise program, performed under direct physiotherapy supervision, would improve functional outcomes such as sub-maximal exercise capacity and self-reported health, and/or vital capacity, at discharge from hospital following coronary artery bypass graft surgery (CABG). We also sought to investigate whether supplementary respiratory and musculoskeletal exercises might further benefit patient outcomes. RELEVANCE: Research investigating physiotherapy following CABG has focused largely on respiratory measures of outcome, such as pulmonary complication rates. We hypothesized that the achievement of positive outcomes, such as improved ability to walk and self-reported health, is more relevant following CABG than measures of respiratory morbidity (which is presently minimized with routine peri-operative care). There is no research available to date investigating the effect of physiotherapy and/or exercise prescription on functional outcomes acutely after CABG. PARTICIPANTS: Patients awaiting first-time CABG at Westmead Private Hospital were invited to participate in the study. Exclusion criteria included planned concomitant surgery, significant musculoskeletal or neurological impairment, non-English speaking background and emergency surgery. 92 patients (80 men, 12 women), mean age 63±9 years were enrolled having given written, informed consent. METHODS: The study was a prospective, single-blinded, randomized controlled trial with 3 treatment arms. Patients were allocated prior to pre-operative physiotherapy assessment to one of: a) a ‘minimal’ intervention group, receiving gentle post-operative mobilization (n=31); b) a ‘walking’ group, receiving a physiotherapy-supervised, moderate intensity walking program (n=31); or c) an ‘exercise’ group, receiving the same walking program, musculoskeletal and respiratory exercises (n=30). Primary outcomes were 6-minute walking assessment distance (6MWA), self-rated health and recovery (using SF-36v2, EQ-5D and QoR-40 questionnaires) and vital capacity. These outcomes were measured pre-operatively, at hospital discharge and at 4 weeks following discharge. ANALYSIS: Linear mixed effects models were fitted to outcome variables. In these models, patient identifier was considered as a random effect, and time and intervention group as fixed effects. For those outcome measures where the p-value for interaction between time and intervention group approached significance, the effect of intervention group was analysed separately at discharge and at follow-up. Two-tailed tests with a 5% significance level were used throughout. RESULTS: 6MWA distance at discharge from hospital for both walking (452±70m) and exercise (431±98m) groups were significantly better than that of the minimal (377±90m) intervention group (p = 0.005, p = 0.022 respectively). These differences were not sustained at 4 week follow-up. There were no differences in self-reported health or vital capacity between minimal, walking and exercise groups at discharge or at 4 week follow-up. CONCLUSIONS: A physiotherapy-supervised, moderate intensity walking program in the inpatient setting following first-time CABG improves sub-maximal exercise capacity at discharge from hospital. Additional respiratory and musculoskeletal exercises confer no further benefits to the assessed outcomes. Further investigation is required to determine the optimal level or dosage of physiotherapy intervention and aerobic exercise following CABG. IMPLICATIONS: The role of physiotherapy following CABG is evolving from one of prophylaxis against respiratory complications to one of fostering early return to exercise and functional activity. KEYWORDS: Exercise, cardiac surgery. FUNDING ACKNOWLEDGEMENTS: Nil. CONTACT: andrew.hirschhorn@bigpond.com.au

ETHICS COMMITTEE: Sydney West Area Health Service Human Research Ethics Committee