Prognostic Value of Preoperative Geriatric Nutritional Risk Index for Long-Term Cardiovascular Mortality in Elderly Patients Undergoing Cardiac Valve Surgery: A Retrospective Cohort Study

Background: Malnutrition frequently occurs in older adults receiving cardiac surgery and is often linked to poor long-term prognosis. In geriatric care, the Geriatric Nutritional Risk Index (GNRI) offers a practical and efficient assessment tool to evaluate malnutrition risk, yet its relationship with cardiovascular mortality following cardiac valve surgery remains inadequately explored. Methods: This research employed a retrospective cohort design with a sample of 170 patients of ≥60 years or older who underwent valve surgery at a tertiary hospital in 2013. To evaluate nutritional status, we employed using GNRI. The principal outcome was cardiovascular death with a median 7.2 years follow-up. Our methodological framework for investigating the GNRI-cardiovascular mortality link integrated three key components: multivariable Cox regression (to estimate hazard ratios), restricted cubic spline modeling (to explore non-linear trends), and Kaplan–Meier analysis (to visualize survival curves). Results: The results indicated a significant inverse linear the correlation of GNRI with the risk of cardiovascular mortality (p for nonlinearity = 0.274). After multivariable adjustment, per unit increment in GNRI showed a significant association 41% decline in the risk of death from cardiovascular causes (hazard ratios (HR): 0.59, 95% CI: 0.38–0.90, p = 0.015). Individuals with GNRI ≤92 had significantly worse long-term survival than those with GNRI >92 (p = 0.0057). Conclusions: Preoperative GNRI is independently related to cardiovascular deaths in elderly postoperative cardiac valve surgery patients. A reduced GNRI signifies a significant marker for late cardiovascular death over the long term in cardiac valve surgery.