Prediction of stent restenosis in patients with Chronic Coronary Syndrome: Evaluation of the prognostic nutritional index

INTRODUCTION: Coronary artery disease is the leading cause of mortality worldwide. Percutaneous coronary intervention, along with modern technology, is a commonly applied treatment method in the management of coronary artery disease. In-stent restenosis remains an unresolved clinical problem in patients undergoing percutaneous coronary intervention. There are various factors thought to contribute to in-stent restenosis, and one of them is malnutrition. Previous studies have reported that malnutrition contributes to the development of many complications in hospitalized patients and leads to adverse outcomes after discharge. Several scoring indices reflecting inadequate nutrition have been associated with hospital stay, cardiovascular events, and mortality. The Prognostic Nutritional Index (PNI) has been used in the literature to indicate the nutritional status. In our study, we aimed to investigate the relationship between the Prognostic Nutritional Index and stent restenosis in patients with chronic coronary syndrome. MATERIALS AND METHODS: Between March 1, 2019, and July 1, 2022, a total of 1007 patients who underwent angiography at Ankara Bilkent City Hospital due to chronic coronary syndrome were included in the study. Among them, 395 patients meeting the criteria were included in the restenosis group (cases), and 612 patients not meeting the criteria were included in the non-restenosis (control) group. Patient data were retrospectively reviewed using hospital records and the e-nabız system. The coronary angiography procedure, including the previous stent placement and the coronary angiography performed at our hospital, was monitored, and necessary data were recorded. The Prognostic Nutritional Index (PNI) was calculated for patients by looking at their laboratory values before coronary angiography, using the formula (10 × albumin (g/dL)) + (0.005 × total lymphocyte count (per mm3)). RESULTS: In the study, a total of 1007 patients with chronic coronary syndrome were examined. The mean age of the patients was 62±10, and 75% of the patients (n=760) were male. When examining the comorbidities of the study patients, 41% had diabetes mellitus (n=411), 67% had hypertension (n=680), 31% had dyslipidemia (n=310), and 14% had chronic renal insufficiency (n=144). Additionally, 30% of the patients (n=304) were smokers. The mean albumin values of the patients included in the study were 42.8±3.5 mg/dL in the non-restenosis group and 44.4±3.7 mg/dL in the restenosis group. A statistically significant difference was observed between the two groups (p<0.001). Mean lymphocyte values were similar between the two groups, and no statistically significant difference was observed. The calculated Prognostic Nutritional Index (PNI) was 42.83±3.53 in the non-restenosis group and 44.43±3.74 in the restenosis group. A statistically significant difference was found between the two groups (p<0.001). When the effect of the Prognostic Nutritional Index on restenosis was statistically examined, the AUC was calculated as 0.64 (0.61-0.68). The cutoff value for PNI was determined as 44, and it predicted stent restenosis with 61% sensitivity and 61% specificity. CONCLUSION: Contrary to the findings in the literature, our study revealed a higher Prognostic Nutritional Index (PNI) value in the group with stent restenosis compared to the non-restenosis group. PNI reflects the current nutritional status, whereas stent restenosis is an outcome of a chronic clinical condition. To clarify the relationship between PNI and stent restenosis in patients with chronic coronary syndrome, there is a need for dynamic measurements of PNI and longer-term prospective studies. Keywords: Prognostic nutritional index, chronic coronary syndrome, in-stent restenosis