# Effect of the prognostic nutritional index on stent restenosis in patients with chronic coronary syndrome

## TL;DR

This study found that a higher Prognostic Nutritional Index is linked to stent restenosis in patients with chronic coronary syndrome, contrary to previous expectations.

## Contribution

The study reveals a novel inverse relationship between high PNI and stent restenosis in chronic coronary syndrome patients.

## Key findings

- Patients with stent restenosis had a significantly higher PNI than those without.
- A PNI cutoff of 44 predicted stent restenosis with 61% sensitivity and 61% specificity.
- The study found a higher PNI in the ISR group, contrary to existing literature.

## Abstract

In-stent restenosis (ISR) remains a significant clinical challenge in patients undergoing percutaneous coronary interventions. We investigated the association between Prognostic Nutritional Index (PNI) and ISR in patients with chronic coronary syndrome.

A total of 1007 patients who underwent coronary angiography for a provisional diagnosis of chronic coronary syndrome between March 1, 2019, and July 1, 2022, were included in the study. They were divided into two groups: ISR (n = 395) and non-ISR (n = 612). PNI was calculated using patients’ laboratory values before coronary angiography with the following formula: PNI = (10 × albumin (g/dL)) + (0.005 × total lymphocyte count (per mm3)).

The mean age of the patients was 62 ± 10 years, and 75% of the patients (n = 760) were male. The calculated PNI was 42.83 ± 3.53 in the non-ISR group and 44.43 ± 3.74 in the ISR group (p < 0.001). When the validity of the PNI for ISR was statistically examined, the AUC was calculated as 0.64 (0.61–0.68). The cutoff value for PNI was determined to be 44, which predicted stent ISR with a sensitivity of 61% and a specificity of 61%.

Contrary to the findings in the literature, our study revealed a higher Prognostic Nutritional Index (PNI) value in the stent ISR group than in the non-ISR group. The PNI reflects the current nutritional status, whereas stent ISR is an outcome of a chronic clinical condition.