Psoas Muscle Index (PMI) as a Predictor of Outcomes After Minimally Invasive Cardiac Surgery

Sarcopenia or muscle loss and function is a component of the frailty syndrome. In this sense, frailty is becoming an important risk factor in predicting outcomes after major surgery and is defined as a geriatric syndrome of decreased reserve and resiliency to stressors that have been associated with adverse health outcomes in older adults. Despite its potentially relevant role in predicting postoperative recovery, frailty is rarely evaluated before surgery, and this is partially due to the low reliability of the most used frailty scores. Therefore, improvement in the frailty evaluation would be beneficial during the preoperative assessment of major surgeries. Sarcopenia, or the decline of skeletal muscle tissue with age, is one of the most important causes of functional decline and loss of independence in older adults and low muscle mass is a core component of frailty that has the advantage of being objectively quantifiable regardless of mobility, disability, or illness acuity. Psoas Muscle (PM) mass is an important parameter for evaluating muscle mass and has been previously correlated to frailty with a negative impact on the postoperative outcomes after major surgery and Psoas Muscle mass Index (PMI) is an easily available parameter for evaluating muscle mass and has already been demonstrated to be effective in predicting outcomes in different clinical settings. PMI has also been shown to be an effective predictor of outcomes in cardiac surgery although there are no studies specifically focusing on minimally invasive cardiac surgery. With this study, the investigators aim to investigate the relevance of PMI as a predictor of postoperative mobilisation, hospital length of stay and clinical recovery after major cardiac surgery conducted via a minimally invasive approach.