Randomised controlled trial protocol for the PROTECT-CS Study: PROTein to Enhance outComes of (pre)frail paTients undergoing Cardiac Surgery.

Introduction: In the past 20 years, the increasing burden of heart disease in an ageing population has resulted in cardiac surgery (CS) being offered to more frail and older patients with multiple comorbidities. Frailty and malnutrition are key geriatric syndromes that impact postoperative outcomes, including morbidity, mortality and prolonged hospital length of stay. Enhanced recovery protocols (ERPs), such as prehabilitation, have been associated with a reduction in complications after CS in vulnerable patients.