Systematic review on the predictive ability of frailty assessment measures in cardiac surgery

Objectives: Patient frailty is increasingly recognised as contributing to adverse postoperative outcomes in cardiothoracic surgery. The goal of this review is to evaluate the predictive ability of frailty scoring systems and their limitations in risk assessment of patients undergoing cardiac surgery. Methods: Frailty studies were identified by searching electronic databases. Studies in which the measuring instrument was defined as a multidimensional tool focusing on a population undergoing cardiac operations were included. The focus was on the predictive ability of frailty in this population and a comparison with conventional risk scoring systems. Unfortunately, the lack of a significant number of studies with the same postoperative outcome precluded a formal meta-analysis. Results: Of 783 studies identified in our initial search, 6 fulfilled our inclusion criteria. Frailty was identified as a predictor of mortality, morbidity and/or prolonged hospital stay in patients undergoing cardiac surgery. Our systematic review revealed the increased application of frailty scores compared to standardized risk stratification scores in cardiothoracic patients. In approximately 50% of these studies, frailty scores continued to be predictive even after adjusting for the conventional risk scoring systems. Conclusions: The assessment of frailty may enhance the preoperative workup and offer an optimized risk stratification measure in patients undergoing cardiothoracic procedures even though the reporting standards of calibration and classification measures have been relatively poor.