# Nutrition-Related Indices and Systemic Inflammation in Acute Coronary Syndrome: Prognostic Utility of PNI with IPI/AISI and Links to Angiographic Severity and Survival

## TL;DR

This study shows that combining inflammation and nutrition markers improves predicting outcomes in heart attack patients.

## Contribution

The study introduces novel inflammation and nutrition indices for improved risk stratification in acute coronary syndrome.

## Key findings

- PNI was independently protective against mortality in ACS patients.
- STEMI patients had shorter survival compared to NSTEMI patients.
- Higher Gensini scores were linked to increased mortality risk.

## Abstract

Background: Acute coronary syndrome (ACS) remains a leading cause of morbidity and mortality worldwide, and improved risk stratification beyond conventional biomarkers is needed. Novel laboratory-derived indices reflecting systemic inflammation and immunonutritional status including the inflammatory prognostic index (IPI), prognostic nutritional index (PNI), and aggregate index of systemic inflammation (AISI) may provide integrated prognostic information in ACS. Methods: In this cohort study, 2400 participants were included: 800 controls, 800 patients with non-ST-elevation myocardial infarction (NSTEMI), and 800 with ST-elevation myocardial infarction (STEMI). Results: Compared with controls, NSTEMI and STEMI patients were younger and exhibited higher body mass index, blood pressure, heart rate, and progressively worse glycemic indices (fasting glucose and HbA1c; all p < 0.001). Lipid parameters were significantly higher in ACS groups versus controls (p < 0.001). Cardiac biomarkers were markedly elevated in ACS, with significantly higher troponin I and CK-MB levels in STEMI than NSTEMI and controls (both p < 0.001). Inflammatory and renal parameters (CRP, fibrinogen, urea, creatinine) were increased in ACS, most prominently in STEMI. Composite indices demonstrated strong inter-correlations, including a strong positive correlation between AISI and IPI (r ≈ 0.91, p < 0.001), while PNI correlated inversely with CONUT score (r ≈ −0.70, p < 0.001). The Gensini score differed significantly among groups and was highest in NSTEMI (p < 0.001). Survival was significantly lower in STEMI than NSTEMI (log-rank p = 0.005), with RMST of 315.5 days in NSTEMI versus 299.4 days in STEMI. In multivariable Cox regression, STEMI presentation independently predicted higher mortality risk (HR 1.26, 95% CI 1.04–1.53; p = 0.018), and higher Gensini score was also independently associated with mortality (HR 1.01 per point; 95% CI 1.00–1.02; p = 0.036). Higher PNI was independently protective (HR 0.997; 95% CI 0.993–1.000; p = 0.045), whereas age and CONUT score were not significant in the adjusted model. Conclusions: Novel laboratory-derived systemic inflammatory and nutrition-related indices particularly IPI and AISI as markers of inflammatory burden and PNI as a marker of immunonutritional balance provide clinically relevant prognostic information in ACS. STEMI presentation is associated with shorter survival, and all-cause mortality is independently related to STEMI status, greater angiographic severity (higher Gensini score), and lower PNI. These readily available indices may offer incremental value for risk stratification in NSTEMI and STEMI when integrated with conventional clinical and angiographic assessment.