PRehabilitiation in Elective Frail and Elderly Cardiac Surgery PaTients

Frailty is a common syndrome among older adults, defined as a "clinically recognizable state of increased vulnerability resulting from aging-associated decline in reserve and function". Fried defined frailty as meeting three out of the five criteria: low grip strength, low energy, slowed walking speed, low physical activity, and/or unintentional weight loss. Clinicians are currently challenged with a rising prevalence of elderly and frail patients presenting for major cardiac surgery. Such patients typically present with a greater comorbidity burden and are more likely to be malnourished, physically deconditioned, and to exhibit decreased physiological adaptation to stress. Frail cardiac surgical patients are, unsurprisingly, at increased risk for major adverse cardiac and cerebrovascular events, short- and longer-term mortality, and increased length of hospital of stay. Clinicians may also struggle to quantify the peri-operative risk of morbidity and mortality among these individuals, since tools such as the Society of Thoracic Surgeons (STS) risk assessment are not designed to comprehensively assess the complex interaction between various risk factors seen in the frail patient.

Cardiovascular rehabilitation (CR) programs are integral to managing patients with cardiovascular disease. Such programs include health behaviour change, and cardiovascular risk factor management (e.g. moderate-to-vigorous-intensity continuous exercise training [MICE], healthy eating, smoking cessation, stress management, and psychological services). The benefits of MICE for patients with cardiovascular disease include improvements in exercise tolerance, muscular strength, cardiovascular health and reduced hospitalizations. MICE is, therefore, able to improve several facets of physical dysfunction, and forms major therapeutic interventions for functional capacity and frailty. Improvements in nutritional status have been observed in patients with cardiovascular disease(CVD) participating in CR, and exercise training and stress management have been shown to reduce distress in CVD patients.

Emerging evidence indicates that CR before cardiac surgery (i.e. prehabilitation [PREHAB]) may improve clinical outcomes. Sawatzky et al. showed that a 12-week PREHAB program consisting of two structured exercise training sessions per week and 12 education sessions concerning cardiovascular risk factor management, exercise, stress, diet, and medication use in patients awaiting coronary artery bypass grafting (CABG) was feasible and significantly improved functional capacity.

Elderly and frail patients are increasingly presenting for cardiac surgery, and these individuals must be carefully optimized pre-operatively to increase the likelihood of their recovery and return to a reasonable quality of life. A personalized PREHAB program that targets and ameliorates the elements of frailty, including low functional capacity, poor nutrition, and stress, offers the best chance of mitigating frailty and its associated risk factors in a way that is feasible, patient-centred, and translatable to other cardiovascular centres. This project will use objective measures, including tests of functional capacity, validated questionnaires, and biomarker analysis, to better quantify the subjective diagnosis of frailty in our patients, and will implement a novel personalized PREHAB program with integrated on-site and home-based exercise sessions, in an attempt to mitigate the frailty and other risk factors that impact patients in the peri-operative period.