Association between preoperative geriatric nutritional risk index and major adverse cardiovascular and cerebrovascular events after non-cardiac surgery in older patients: a retrospective cohort study.

BACKGROUND

Preoperative nutritional status impacts surgical outcomes. This study aimed to examine the association between preoperative Geriatric Nutritional Risk Index (GNRI) and the incidence of postoperative major adverse cardiovascular and cerebrovascular events (MACCE) in older patients undergoing non-cardiac surgery, as well as the predictive value of GNRI for MACCE.

METHODS

This retrospective cohort study analyzed data from the INSPIRE database (version 1.3), a nationally representative surgical registry in South Korea, with data collected between 2011 and 2020. We included patients aged 65 years or older who underwent non-cardiac surgery. Preoperative malnutrition risk was categorized using the GNRI: at risk of malnutrition (GNRI ≤ 98) and no risk of malnutrition (GNRI > 98). The primary outcome was the incidence of 90-day postoperative MACCE, defined as a composite of non-fatal cardiac arrest, angina, acute myocardial infarction, heart failure, new cardiac arrhythmia, stroke, or any combination of these.

RESULTS

Among 30,591 included patients (median age, 70 years [interquartile range, 65–75]; 49.9% male), 4,834 (15.8%) were at risk of preoperative malnutrition (GNRI ≤ 98). Overall, 762 patients (2.5%) experienced a primary endpoint event. The 90-day MACCE incidence was 2.1% in patients without risk of malnutrition and 4.4% in those with risk of malnutrition (Log-rank P < 0.001). Patients at risk of malnutrition (GNRI ≤ 98) exhibited a significantly higher MACCE risk after adjustment for confounders (Fully adjusted hazard ratio, 1.40 [95% CI, 1.16–1.69]; P < 0.001). Further restricted cubic spline analysis revealed a nonlinear relationship between GNRI and MACCE risk. Incorporating GNRI into the Revised Cardiac Risk Index (RCRI) model significantly improved the C-statistic, net reclassification improvement (NRI), and integrated discrimination improvement (IDI) (all P < 0.05).

CONCLUSIONS

Lower preoperative GNRI was independently associated with an increased risk of 90-day postoperative MACCE in older patients undergoing non-cardiac surgery. Incorporating GNRI into risk prediction models alongside factors like the RCRI may improve predictive accuracy for MACCE.