Assessment and Utility of Frailty Measures in Critical Illness, Cardiology, and Cardiac Surgery

Frailty is a clearly emerging theme in acute care medicine, with obvious prognostic and health resource implications. "Frailty" is a term used to describe a multidimensional syndrome of loss of homeostatic reserves that gives rise to a vulnerability to adverse outcomes after relatively minor stressor events. This is conceptually simple, yet there has been little consensus on the operational definition. The gold standard method to diagnose frailty remains a comprehensive geriatric assessment; however, a variety of validated physical performance measures, judgement-based tools, and multidimensional scales are being applied in critical care, cardiology, and cardiac surgery settings, including open cardiac surgery and transcatheter aortic value replacement. Frailty is common among patients admitted to the intensive care unit and correlates with an increased risk for adverse events, increased resource use, and less favourable patient-centred outcomes. Analogous findings have been described across selected acute cardiology and cardiac surgical settings, in particular those that commonly intersect with critical care services. The optimal methods for screening and diagnosing frailty across these settings remains an active area of investigation. Routine assessment for frailty conceivably has numerous purported benefits for patients, families, health care providers, and health administrators through better informed decision-making regarding treatments or goals of care, prognosis for survival, expectations for recovery, risk of complications, and expected resource use. In this review, we discuss the measurement of frailty and its utility in patients with critical illness and in cardiology and cardiac surgery settings.