Preoperative nutritional state is associated with mid- and long-term mortality after cardiac surgery

Background: The frailty score has been developed to determine physiological functioning capacity. The aim of our research was to explore the relationship between frailty factors and mortality in cardiac surgery patients. Methods: Our research is an observational, single-center, prospective cohort study (registered on ClinicalTrials.gov: NCT02224222), and we studied 69 patients who underwent elective cardiac surgery between 2014 and 2017. Thirty days before the surgery, they completed a questionnaire that contained questions related to social support, self-reported life quality-happiness, cognitive functions, anxiety and depression. Demographic, anthropometric and medical data were widely collected. The Geriatric Nutritional Risk Index (GNRI) and the Comprehensive Geriatric Assessment (CGA)-based frailty index were calculated as a sum and the domains, respectively. Cox regression and the Kaplan-Meier tests were applied to analyze survival and relative risk. The primary outcome was mid-term mortality. Results: The patients' mean age was 65.43 years [standard deviation (SD): 9.81 years]. The median followup was 1,656 days of survival [interquartile range (IQR), 1,336-2,081 years], during this period 14 patients died. The median of EuroSCORE II was 1.56 (1.00-2.58) points. The median preoperative albumin level was 32.80 g/L (IQR, 29.9-35.8 g/L). Major adverse cardiovascular and cerebral events (MACCEs) occurred 7 times during follow-up. The nutrition score of the CGA was significantly associated with worse long-term survival [score; hazard ratio (HR): 5.35; 95% CI: 1.10-25.91, P=0.037]. After adjustment for EuroSCORE II and postoperative complications the noncardiovascular CGA score was associated with overall mortality [adjusted hazard ratio (AHR): 1.44, 95% CI: 1.02- 2.04, P=0.036]. In the multivariable Cox regression, GNRI <91 showed an increased risk for mortality (AHR: 4.76, 95% CI: 1.52-14.92, P=0.007). Conclusions: The CGA-based noncardiovascular score and nutritional status should be assessed before cardiac surgery prehabilitation and may help decrease long-term mortality.