Poor Preoperative Nutritional Status, but Not Hormone Levels, Are Associated With Mortality After Cardiac Surgery

The authors’ aim was to examine the preoperative hormone and nutritional status in patients undergoing elective cardiac surgery. The authors’ research was a single-center, prospective, observational study (ClinicalTrials.gov: NCT03736499). The authors examined 252 patients who underwent elective cardiac surgery. Preoperative thyroid-stimulating hormone (TSH), free triiodothyronine (fT3), free thyroxine (fT4), prolactin, and testosterone levels were collected and analyzed after the surgery. The Geriatric Nutritional Risk Index (GNRI), Controlling Nutritional Status (CONUT), and Prognostic Nutritional Index (PNI) were all calculated as a sum and groups. Frailty was calculated based on the modified Frailty Index-11. The primary outcome was overall mortality. The mean age of the patients was 64.23 years (standard deviation: 11.07 years). Thirty-three patients (13.01%) died during the median follow-up time of 20.48 months (interquartile range: 18.90-22.98 months). Thyroid hormones were examined as continuous variables and also in 3 groups based on low, normal, and high hormone levels. Continuous TSH (p = 0.230), continuous fT3 (p = 0.492), and continuous fT4 (p = 0.657) were not significantly associated with total mortality. After adjustment for the European System for Cardiac Operative Risk Evaluation II and postoperative complications, the following nutritional scores were associated with total mortality: GNRI < 91 (adjusted hazard ratio [AHR]: 4.384; 95% confidence interval [CI]: 1.866-10.303, p = 0.001), the higher CONUT group (AHR: 1.736; 95% CI: 1.736-2.866, p = 0.031), and a PNI < 48 points (AHR: 3.465; 95% CI: 1.735-6.918, p < 0.001). The modified Frailty Index-11 was not associated with mortality. Before cardiac surgery, nutritional status should be assessed because the findings may help to decrease mortality. The hormone levels were not associated with mortality.