PhysiotheRapy following OPen HEart SurgerY (PROPHESY): A feasibility study investigating physical activity following open heart surgery

BACKGROUND: Early mobilisation following open heart surgery (OHS) may improve recovery; however, optimal timing and dosage remains unclear. The aim of this feasibility study is to evaluate recruitment and data collection processes, assess the feasibility of accelerometer-based activity measurement, and describe postoperative physical activity and exploratory clinical outcomes. METHODS: Eligible patients undergoing OHS were recruited prior to or during their inpatient stay and were asked to wear a triaxial accelerometer (ActiGraph GT3X) for the first 7 postoperative days (PODs). Feasibility outcomes included recruitment rates, ActiGraph wear adherence, and data completeness. Physical activity was measured using step count and nonsedentary time, while functional outcomes were assessed using the 2-min walk test and 5-times sit-to-stand test. A post hoc regression analysis was used to explore associations between activity and clinical outcomes. RESULTS: Of 178 patients screened, 64% of eligible patients were recruited. Activity data were collected for 98% of participants, with high wear adherence (87%). Outcome measure collection was limited by weekend discharges, with 55% of participants having complete datasets. Patient activity increased day-on-day to POD 5, with higher activity on POD 2 associated with reduced postoperative hospital length of stay. CONCLUSION: Recruitment and accelerometer-based activity monitoring post OHS were feasible, although limited by weekday-only processes. Exploratory post hoc analyses suggested a possible relationship between higher activity on POD 2 and shorter postoperative hospital length of stay; however, these findings should be considered hypothesis generating due to the small sample size and lack of adjustment for confounding.