Association of the prognostic nutritional index and geriatric nutritional risk index with clinical outcomes in patients undergoing coronary artery bypass surgery: a systematic review and meta-analysis.

BACKGROUND

The association between preoperative prognostic nutritional index (PNI) and geriatric nutritional risk index (GNRI) and clinical outcomes in patients receiving coronary artery bypass surgery (CABG) remains unclear now. This study aimed to clarify the associations of the PNI and the GNRI with clinical outcomes among patients who underwent CABG.

METHODS

The PubMed, Embase, and Web of Science databases were searched up to July 11, 2025. Studies that investigated the relationships between the PNI and GNRI and clinical outcomes, such as long-term and short-term mortality and postoperative complications, were included. Odds ratios (ORs) with 95% confidence intervals (CIs) were combined.

RESULTS

Twenty-one observational cohort studies involving 14,523 patients undergoing CABG were included in this meta-analysis. Most studies were retrospective in design, and follow-up periods ranged from in-hospital outcomes to long-term mortality. For PNI, the pooled results demonstrated that a lower PNI was related to an increased risk of long-term mortality (OR =0.91, P<0.001), short-term mortality (OR =0.88, P=0.01), acute kidney injury (AKI) (OR =0.73, P=0.009), major adverse cardiac and cerebrovascular events (OR =0.774, P<0.001), atrial fibrillation (OR =0.92, P=0.02), neurologic complications (OR =0.61, P=0.041), hemorrhage (OR =0.123, P=0.025), hospital-acquired infection (OR =0.472, P<0.001), and intra-aortic balloon pump use (OR =0.372, P<0.001), but the PNI was not associated with the risk of postoperative overall complications (P=0.13) or pulmonary complications (P=0.663). Only three studies evaluated GNRI. The GNRI was only associated with the risk of short-term mortality (OR =0.91; P=0.03), and no significant relationship between the GNRI and AKI (P=0.42) or major adverse cardiac or cerebrovascular events (OR =0.195) was observed.

CONCLUSIONS

Based on the current evidence, the PNI was associated with clinical outcomes in patients who underwent CABG, and lower PNI indicated increased risk of postoperative mortality and complications.