Frailty, Aging, and Cardiovascular Surgery.

Older adults make up an ever-increasing number of patients presenting for surgery, and a significant percentage of these patients will be frail. Frailty is a geriatric syndrome that has been conceptualized as decreased reserve when confronted with stressors, although the precise definition of frailty has not been easy to standardize. The 2 most popular approaches to define frailty are the phenotypic approach and the deficit accumulation approach, although at least 20 tools have been developed, which has made comparison across studies difficult. In epidemiologic studies, baseline frailty has been associated with poor outcomes in both community cohorts and hospitalized patients. Specifically in cardiac surgery (including transcatheter aortic valve implantation procedures), frailty has been strongly associated with postoperative mortality and morbidity, and thus frailty likely improves the identification of high-risk patients beyond known risk scores. For perioperative physicians then, the question arises of how to incorporate this information into perioperative care. To date, 2 thrusts of research and clinical practice have emerged: (1) preoperative identification of high-risk patients to guide both patient expectations and surgical decision-making; and (2) perioperative optimization strategies for frail patients. However, despite the strong association of frailty and poor outcomes, there is a lack of well-designed trials that have examined perioperative interventions with a specific focus on frail patients undergoing cardiac surgery. Thus, in many cases, principles of geriatric care may need to be applied. Further research is needed to standardize and implement the feasible definitions of frailty and examine perioperative interventions for frail patients undergoing cardiac surgery.