Abstract
Objective
Patients with a prior history of coronary artery bypass grafting (CABG) presenting with non–ST-elevation acute coronary syndrome (NSTE-ACS) represent a high-risk population in whom revascularization decisions are frequently individualized in real-world practice. Objective biomarkers capable of supporting treatment selection in this setting remain limited. The Naples Prognostic Score (NPS), a composite index integrating inflammatory and nutritional parameters, may reflect overall clinical vulnerability.
Methods
In this retrospective, single-center observational cohort study, the association between NPS and treatment strategy selection was evaluated in 367 patients with prior CABG presenting with NSTE-ACS between January 2019 and October 2025. NPS was calculated at admission prior to coronary angiography using total cholesterol, neutrophil-to-lymphocyte ratio, lymphocyte-to-monocyte ratio, and serum albumin levels. Patients were categorized into low (0–2) and high (3–4) NPS groups. Treatment strategies were determined through routine multidisciplinary clinical assessment and were not influenced by study investigators. Multivariable logistic regression and prespecified stratified sensitivity analyses were performed.
Results
Revascularization was selected in 169 patients (46.0%), including 164 percutaneous coronary interventions and 5 redo CABG procedures. Patients undergoing revascularization had significantly lower NPS values. High NPS was independently associated with a lower likelihood of being selected for revascularization (OR 0.28, 95% CI 0.17–0.48; p < 0.001). Procedural success rates following PCI were similar between NPS groups (89.0% overall; p = 0.161). Results remained consistent across stratified sensitivity analyses according to clinical presentation, chronic kidney disease status, and age categories.
Conclusions
Higher NPS values were associated with a lower likelihood of revascularization without affecting procedural success. NPS appears to reflect disease burden and clinical vulnerability rather than treatment benefit. It may also capture acute inflammatory status and should be considered a complementary, not decisive, clinical marker.
Keywords
1. Introduction
Cardiovascular diseases remain among the leading causes of morbidity and mortality worldwide. 1 In the management of coronary artery disease, coronary revascularization strategies are considered key components alongside optimal medical therapy. In patients with complex coronary lesions, coronary artery bypass grafting (CABG) is commonly recommended as a preferred revascularization strategy because of its established long-term clinical benefits. 2
However, in patients undergoing CABG, concomitant comorbidities and increased systemic inflammatory burden may adversely affect graft patency.3,4 Modifiable risk factors such as cigarette smoking may further contribute to accelerated graft degeneration. Progressive graft dysfunction can result in impaired myocardial perfusion and, over time, may facilitate the development of acute coronary syndromes (ACS).
In patients with a prior history of CABG presenting with ACS, coronary angiography (CAG) frequently results in continuation of optimal medical therapy, depending on native coronary anatomy and graft patency.5,6 Recent clinical studies suggest that a routine invasive strategy in this patient population does not confer a significant benefit in terms of mortality or morbidity. 7 Accordingly, decisions regarding revascularization should be made using a more selective, individualized, and risk-based approach. However, objective biomarkers capable of supporting revascularization decision-making in patients with prior CABG presenting with NSTE-ACS remain poorly defined. Current risk assessment primarily relies on clinical judgment and angiographic findings, highlighting the need for complementary tools reflecting systemic disease burden.
Graft degeneration in patients with prior CABG is known to be closely associated with inflammatory and metabolic processes.3,8 The Naples Prognostic Score (NPS) is a composite index that simultaneously reflects systemic inflammation and nutritional status. 9 NPS has emerged as a potential biomarker reflecting both systemic inflammation and nutritional status, factors closely linked to frailty, diffuse atherosclerosis, and clinical suitability for invasive strategies.
Despite this, clinical or biomarker-based models capable of supporting revascularization decision-making in patients with prior CABG presenting with Non–ST-Elevation Acute Coronary Syndrome (NSTE-ACS) remain limited. This represents a significant gap in the current literature. To our knowledge, no previous study has specifically evaluated the relationship between NPS and treatment strategy selection in this high-risk population. Therefore, the aim of the present study was to investigate whether the NPS is associated with real-world revascularization decision-making and procedural outcomes in patients with prior CABG presenting with NSTE-ACS.
2. Methods
2.1. Study population
Between January 2019 and October 2025, a total of 440 patients with a prior history of CABG who presented with NSTE-ACS were retrospectively evaluated at Antalya Training and Research Hospital in an observational study design. During the screening process, patients presenting with high-risk NSTE-ACS, ST-elevation myocardial infarction (STEMI), stable angina pectoris, active infection, malignancy, use of immunosuppressive therapy, or incomplete medical records were excluded from the analysis.
High-risk NSTE-ACS was defined according to contemporary guideline criteria, including hemodynamic instability, refractory chest pain despite medical therapy, life-threatening arrhythmias, or dynamic ST-segment changes requiring immediate invasive management. 1
After application of these exclusion criteria, a total of 367 patients aged ≥18 years who were diagnosed with NSTE-ACS constituted the final study cohort.
This retrospective, single-center observational study was conducted in accordance with the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines 10 and the ethical principles of the Declaration of Helsinki (1975), as revised in 2024. Clinical and laboratory data were retrieved from the hospital’s electronic medical record system, outpatient clinic documentation, archived reports, and physical patient files. The study protocol was approved by the Antalya Training and Research Hospital Ethics Committee on November 27, 2025 (Protocol No: 20/06). Owing to the retrospective design of the study, the requirement for written informed consent was waived in accordance with institutional regulations. All patient data were anonymized and de-identified prior to analysis. The diagnosis of NSTE-ACS was established according to current international clinical guidelines. 1
2.2. Laboratory measurements and NPS calculation
All biochemical and hematological measurements were performed using venous blood samples obtained within the first 24 hours after hospital admission and prior to coronary angiography.
Because sampling was performed during the acute phase of hospitalization, laboratory parameters were interpreted as reflecting acute inflammatory and metabolic status rather than baseline nutritional condition.
The biochemical parameters evaluated included blood urea nitrogen (BUN), creatinine, sodium, potassium, estimated glomerular filtration rate (eGFR), total cholesterol (TC), low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, triglycerides, serum albumin (ALB), and serum uric acid levels. These parameters were measured using a fully automated AU5800 analyzer (Beckman Coulter Inc., Brea, CA, USA) with spectrophotometric methods.
Complete blood count parameters—including white blood cell count, hemoglobin, platelet count, and leukocyte subtypes—were analyzed using a Sysmex XN-1000 hematology analyzer (Sysmex Corporation, Kobe, Japan). Derived inflammatory indices, including neutrophil-to-lymphocyte ratio (NLR) and lymphocyte-to-monocyte ratio (LMR), were subsequently calculated.
NPS is a four-component composite score derived from TC, NLR, LMR, and ALB levels. 9 The predefined cutoff values used were those originally described in the literature: total cholesterol ≤180 mg/dL, albumin <4.0 g/dL, NLR >2.96, and LMR ≤4.44, each assigned 1 point. 9 The total NPS ranged from 0 to 4.
For analytical purposes, patients were stratified into low (NPS 0–2) and high (NPS 3–4) risk groups. In addition, sensitivity analyses were performed treating NPS as an ordinal variable to evaluate the robustness of the observed associations.
2.3. Coronary Angiography and treatment Strategy
Based on coronary angiographic findings, patients were classified according to treatment decisions—either medical therapy or revascularization—made during routine clinical practice.
Treatment decisions were made through multidisciplinary discussion between interventional cardiology and cardiovascular surgery teams and were not influenced by the investigators. Therefore, the primary endpoint reflects treatment selection rather than treatment efficacy.
Revascularization was defined as either percutaneous coronary intervention or surgical revascularization.
In patients who underwent revascularization, procedural success was defined as achievement of post-procedural Thrombolysis In Myocardial Infarction (TIMI) flow grade ≥3, as previously described. 11
All patients received guideline-directed medical therapy in accordance with current international recommendations, 1 including antiplatelet therapy (single or dual, as clinically indicated), high-intensity statins, beta-blockers, and renin–angiotensin system inhibitors when appropriate. Anti-anginal medications were administered as clinically indicated.
In this study, “medical therapy” refers to the continuation of guideline-based pharmacological treatment without revascularization, whereas patients undergoing revascularization received medical therapy in addition to the interventional procedure. Due to the retrospective design, detailed information regarding treatment intensity (e.g., dual antiplatelet therapy use and statin dosing) was not uniformly available.
2.4. Statistical analysis
Statistical analyses were performed using IBM SPSS Statistics for Windows, version 27 (IBM Corp., Armonk, NY, USA). Continuous variables were assessed for normality using the Kolmogorov–Smirnov test and visual inspection of histograms.
Normally distributed continuous variables are presented as mean ± standard deviation and were compared using the Student’s t-test. Non-normally distributed variables are expressed as median (interquartile range) and were compared using the Mann–Whitney U test. Categorical variables are presented as counts and percentages and were compared using the chi-square test or Fisher’s exact test, as appropriate.
The association between NPS categories and treatment strategy was evaluated using the chi-square test, and the phi (Φ) coefficient was calculated to estimate effect size.
To identify factors associated with revascularization, multivariable logistic regression analysis was performed. Variables with clinical relevance and/or p < 0.10 in univariable analyses were entered into the model. The dependent variable was revascularization (yes = 1). Continuous variables were entered as continuous parameters. Due to skewed distribution, troponin levels were log-transformed before inclusion.
To address potential residual confounding inherent to observational treatment allocation, prespecified stratified sensitivity analyses were performed according to clinical presentation (Non–ST Elevation Myocardial Infarction [NSTEMI] vs unstable angina), chronic kidney disease status, and age categories.
Multicollinearity among covariates was assessed using variance inflation factors, and model stability was evaluated considering events-per-variable ratios.
Results are presented as odds ratios with 95% confidence intervals. Model performance was assessed using the Omnibus test and Nagelkerke R2.
A two-sided p value <0.05 was considered statistically significant. No formal sample size calculation was performed due to the retrospective design. All consecutive eligible patients meeting the inclusion criteria during the study period were included in the analysis.
3. Results
A total of 367 patients with a previous history of CABG who presented with NSTEMI or unstable angina were included in the study. Based on routine multidisciplinary clinical decision-making following coronary angiography, 198 patients (54.0%) were managed with medical therapy, whereas 169 patients (46.0%) were selected for coronary revascularization.
According to the NPS, 221 patients (60.2%) were classified as low NPS (0–2) and 146 patients (39.8%) as high NPS (3–4).
Baseline clinical and laboratory characteristics according to treatment strategy.
Values are mean ± SD or †median (interquartile range). Bold values indicate statistically significant results (p < 0.05).
Patients who underwent revascularization had significantly higher lymphocyte counts and more favorable inflammatory indices, including a lower NLR and a higher LMR. Accordingly, mean NPS values were significantly lower among patients selected for revascularization compared with those managed medically (2.01 ± 1.08 vs. 2.43 ± 1.01, p < 0.001).
Median troponin levels were significantly higher among patients selected for revascularization, whereas C-reactive protein levels did not differ between groups. Given the wide distribution of troponin values, results should be interpreted with caution. NSTEMI presentation was significantly more frequent in the revascularization group, while unstable angina was more common among patients managed with maximal medical therapy.
Association between Naples prognostic score category and treatment strategy.
p value derived from chi-square test. Bold values indicate statistically significant results (p < 0.05).
Overall, revascularization was recommended in 169 patients. Among these, 5 patients were referred for redo coronary artery bypass grafting, whereas 164 patients underwent percutaneous coronary intervention (PCI).
Distribution of target vessel according to Naples score category.
p value derived from chi-square test. Bold values indicate statistically significant results (p < 0.05).
Procedural success according to Naples prognostic score category.
p value derived from chi-square test. Bold values indicate statistically significant results (p < 0.05).
Multivariable logistic regression analysis for predictors of revascularization Dependent variable: Revascularization (yes = 1).
Results were consistent across prespecified stratified sensitivity analyses according to clinical presentation (NSTEMI vs. unstable angina), chronic kidney disease status, and age categories, with no significant interaction observed between NPS and subgroup variables.
4. Discussion
This study demonstrates an association between the NPS and revascularization decision-making in patients with a prior history of CABG presenting with NSTE-ACS. The principal finding is that patients with higher NPS values were less likely to undergo revascularization, independent of conventional clinical and laboratory parameters. Importantly, NPS was not associated with procedural success. These findings should be interpreted as reflecting the likelihood of being selected for revascularization within routine clinical practice rather than indicating a causal effect of NPS on treatment benefit or appropriateness.
CABG is a widely preferred revascularization strategy in patients with complex coronary lesions, including multivessel disease and left main coronary artery involvement. Despite advances in surgical techniques and the effective implementation of secondary prevention strategies, approximately 2–6% of patients present annually with acute coronary syndrome following CABG. 12 In this patient population, long-term clinical outcomes vary according to the type of graft used, with saphenous vein grafts demonstrating lower patency rates compared with arterial grafts. 13
In high-risk patients presenting with ACS, an early invasive strategy with CAG is generally recommended. 1 However, previous studies have reported that routine coronary angiography is performed less frequently in patients with NSTE-ACS who have a prior history of CABG.5,14,15 Available evidence indicates that the likelihood of percutaneous coronary intervention is lower in this patient population and that an interventional approach is adopted more selectively.16–18
Moreover, interventional procedures performed in patients with prior CABG are often associated with longer procedural times, increased contrast agent use, and a higher risk of neurological complications, thereby increasing the likelihood of contrast-induced nephropathy. In addition, extensive coronary calcification and advanced atherosclerotic lesions further increase procedural complexity and complication risk.7,19 Consequently, decisions regarding invasive evaluation in NSTE-ACS patients with a history of CABG require careful patient selection and individualized risk assessment.
Malnutrition and increased systemic inflammation are closely associated with adverse cardiovascular outcomes and graft degeneration.3,8,20,21 The NPS, a composite index that simultaneously reflects nutritional status and inflammatory burden, captures the clinical manifestations of these underlying pathophysiological processes. Recent studies have demonstrated that NPS has been reported as an important factor associated with prognosis in patients with NSTE-ACS, ST-elevation myocardial infarction (STEMI), and decompensated heart failure.21–23 In the present study, however, NPS should be interpreted primarily as a marker associated with clinical vulnerability and overall disease burden rather than a determinant of therapeutic strategy.
In our cohort, patients with low NPS values (0–2) were substantially more likely to undergo revascularization, whereas those with high NPS values (3–4) were predominantly managed with optimal medical therapy. Importantly, treatment decisions were made through routine multidisciplinary evaluation. They were not influenced by the study investigators. The observed association likely reflects real-world clinical judgment. Patients with higher inflammatory burden, greater comorbidity load, or diffuse coronary disease may be considered less suitable candidates for invasive treatment.
Although detailed procedural decision variables were not systematically recorded, several common clinical reasons may explain conservative management in this population. These include the absence of suitable revascularization targets, diffuse native or graft disease, poor distal runoff, advanced comorbidity, or perceived procedural risk.
Importantly, this observation extends previous literature that primarily focused on the prognostic value of NPS in predicting long-term outcomes such as mortality and major adverse cardiovascular events.21–23 In contrast, our study highlights the role of NPS in guiding real-world therapeutic decision-making, particularly in a high-risk population with a prior history of CABG.
A recently published study demonstrated that the NPS is an independent predictor of saphenous vein graft (SVG) disease CABG. 20 In that study, SVG degeneration was primarily assessed using angiographic findings, and a heterogeneous population of patients undergoing CAG after CABG was evaluated. Consequently, NPS was interpreted mainly as an anatomical marker of graft pathology rather than a tool reflecting broader clinical decision-making processes.
An important consideration is that all laboratory parameters used to calculate NPS were obtained during the acute phase of hospitalization. Albumin and total cholesterol levels may be influenced by acute inflammatory responses, hemodilution, or metabolic stress. Therefore, in the present study, NPS may reflect acute illness severity, systemic inflammatory activation, or frailty rather than baseline nutritional status. This limitation should be considered when interpreting the observed associations.
Regarding angiographic and procedural outcomes, the distribution of target vessels—native coronary arteries versus saphenous vein grafts—did not differ significantly between low and high NPS groups. In addition, comparable procedural success rates across NPS categories indicate that once revascularization was deemed appropriate, short-term technical outcomes were not influenced by NPS. The very low frequency of redo CABG procedures reflects contemporary clinical practice in post-CABG patients, in whom repeat surgery is rarely preferred due to increased operative risk.
An unexpected finding was the inverse association between higher log-transformed troponin levels and revascularization. This observation should be interpreted cautiously. In patients with prior CABG, elevated troponin levels may reflect extensive myocardial injury, diffuse coronary disease, or clinical instability, factors that may lead clinicians to favor conservative management. Residual confounding, selection bias, or unmeasured clinical variables cannot be excluded, and this finding should be regarded as hypothesis-generating rather than mechanistic.
Several limitations of this study should be acknowledged. The retrospective and single-center design limits causal inference and may reduce the generalizability of the findings, particularly given the relatively modest sample size. Because treatment allocation was not randomized, residual confounding related to clinical judgment, patient frailty, symptom burden, and angiographic complexity cannot be excluded. The analyses were based on laboratory parameters obtained at a single time point at admission, which precluded evaluation of temporal changes in the NPS; moreover, because sampling occurred during the acute phase, measured parameters may reflect acute inflammatory and metabolic responses rather than baseline nutritional status. Furthermore, the absence of angiographic complexity scores such as the SYNTAX score represents an important limitation, as anatomical disease burden is a major determinant of revascularization decisions.
Although all patients received guideline-directed medical therapy, detailed information regarding treatment intensity (e.g., dual antiplatelet therapy and statin dosing) was not consistently available due to the retrospective design, which may have introduced heterogeneity in medical management. Finally, long-term clinical outcomes, including mortality and major adverse cardiovascular events, were not assessed, and therefore the clinical benefit of NPS-associated treatment selection cannot be determined.
5. Conclusions
In patients with prior CABG presenting with NSTE-ACS, a higher NPS was independently associated with a lower likelihood of undergoing revascularization, without influencing procedural success. These findings suggest that NPS may reflect overall clinical vulnerability and factors influencing physician treatment selection rather than treatment efficacy. Accordingly, NPS should be considered a supportive and complementary biomarker that may help contextualize clinical decision-making, but should not be interpreted as a determinant of whether revascularization should be performed. Given the observational design, these findings should be interpreted as associative rather than causal. Future prospective studies incorporating angiographic complexity and long-term clinical outcomes are required to clarify the clinical role of NPS in treatment stratification in this population.
Footnotes
Acknowledgements
AI-assisted language editing was performed using ChatGPT (OpenAI) to improve grammar and readability. No AI tools were used in data analysis, interpretation, or scientific decision-making.
Ethical considerations
Approved by the Antalya Training and Research Hospital Ethics Committee (27 November 2025; Protocol No: 20/06).
Consent to participate
In Turkey there is no requirement to obtain informed consent from individuals in retrospective studies. According to the Antalya Training and Research Hospital Clinical Research Ethics Committee, obtaining consent for participation is considered unnecessary. Informed consent was waived due to the retrospective design.
Consent for publication
The manusscipt does not contain any individual person’s data as in details, images or videos.
Author contributions
Conceptualization: RA, MRE, AÜK; Methodology: RA, MRE, AÜK; Formal analysis and investigation: RA, AÜK; Writing-original draft preparation: RA,AÜK; Writing-review and editing: RA, MRE, AÜK; Funding acquisition: None; Supervision: RA, MRE, AÜK; All authors consent for this version of the paper to be published.
Funding
The authors received no financial support for the research, authorship, and/or publication of this article.
Declaration of conflicting interests
The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Data Availability Statement
The data sets created and/or analyzed during the current study are not publicly available because they contain patient information, but data supporting the findings of this study can be obtained from the corresponding author (RA) upon reasonable request.