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

Background/aim: 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. Materials and methods: 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)). Results: 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%. Conclusion: 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.