The Prognostic Nutritional Index (PNI) and Sepsis-Induced Cardiomyopathy (SCM) Risk in the ICU: A Retrospective Study with L-Shaped Analysis

Why It Matters

Identifying low‑PNI patients enables clinicians to target nutritional and immune support, potentially lowering SCM‑related mortality in the ICU.

Key Takeaways

• PNI <35 linked to 10% higher SCM risk per unit drop
• SCM incidence fell from 83% to 45% across PNI tertiles
• Multivariate analysis shows each PNI point cuts odds by ~9%
• Patients with PNI ≥38.65 had 84% lower SCM odds
• PNI can guide early echocardiography and nutritional interventions

Pulse Analysis

Sepsis remains a leading cause of intensive‑care admissions, and sepsis‑induced cardiomyopathy (SCM) complicates up to two‑thirds of these cases. Existing severity scores such as SOFA and APACHE II capture overall organ dysfunction but lack specificity for myocardial injury. Consequently, clinicians have sought simple, readily available biomarkers that can flag patients at heightened cardiac risk before overt dysfunction manifests. The prognostic nutritional index (PNI), calculated from serum albumin and lymphocyte count, reflects both nutritional reserves and immune competence—two domains known to influence sepsis outcomes.

In a single‑center retrospective study of 200 septic adults, researchers stratified patients into three PNI tertiles and tracked SCM development using NT‑proBNP thresholds and left‑ventricular ejection fraction. The overall SCM rate was 63%, yet it fell dramatically from 83% in the lowest PNI group to 45% in the highest. Logistic models adjusted for demographics, comorbidities, and severity scores consistently yielded an odds ratio of ~0.91 per PNI point, indicating a near‑10% risk reduction per unit increase. Restricted cubic spline analysis uncovered an L‑shaped curve with a turning point near PNI ≈ 35; below this, each additional point markedly lowered SCM odds, while above it the benefit plateaued.

These findings position PNI as a low‑cost, bedside risk‑stratification tool that can trigger early cardiac monitoring, targeted albumin supplementation, and aggressive nutritional support for vulnerable patients. While the study’s retrospective, single‑hospital design limits generalizability, the robust association across multiple adjusted models and subgroups suggests broad applicability. Prospective multicenter trials are needed to confirm causality and to explore whether PNI‑guided interventions can translate into reduced ICU mortality and shorter lengths of stay.