Background and Objectives: Residual coronary anatomical complexity following culprit-lesion-only percutaneous coronary intervention (PCI) remains a major determinant of clinical outcomes in patients with multivessel coronary artery disease (CAD). Platelet distribution width (PDW), a marker of platelet heterogeneity and activation, has been associated with adverse cardiovascular outcomes; however, its relationship with post-procedural residual disease burden remains unclear. This study aimed to evaluate the association between PDW and residual SYNTAX (Synergy between Percutaneous Coronary Intervention with Taxus and Cardiac Surgery) score and to determine its incremental predictive value beyond established clinical variables. Materials and Methods: In this retrospective, single-center study, 140 patients with multivessel CAD undergoing culprit-lesion-only PCI followed by planned staged revascularization were included. Clinical presentation was categorized as chronic coronary syndrome (CCS), non-ST-elevation myocardial infarction (NSTEMI), or ST-elevation myocardial infarction (STEMI). Residual SYNTAX score was calculated after the index procedure, and patients were stratified into low (≤22) and high (≥23) groups. Associations between PDW and residual SYNTAX score were assessed using correlation and regression analyses. Model discrimination and incremental predictive value were evaluated using ROC analysis, hierarchical logistic regression, and reclassification metrics. Nonlinear relationships were explored using restricted cubic spline analysis, and clinical utility was assessed by decision curve analysis. Results: PDW was significantly correlated with residual SYNTAX score (Spearman ρ = 0.503, p < 0.001) and increased progressively across SYNTAX severity strata and clinical presentation groups. In multivariable analysis, PDW remained independently associated with high residual SYNTAX score (OR 1.38, 95% CI 1.07–1.82, p = 0.016). The addition of PDW to a hierarchical clinical model significantly improved model performance (ΔR² = 0.049, p = 0.012). Although the improvement in area under the curve (AUC) was modest, reclassification analyses demonstrated significant net reclassification and discrimination improvements. Spline analysis revealed a nonlinear relationship, with a marked increase in risk beyond PDW levels of approximately 13 fL. Decision curve analysis confirmed the clinical utility of PDW across a range of threshold probabilities. Conclusions: PDW is independently associated with post-procedural coronary anatomical complexity and provides incremental predictive value beyond established clinical variables. However, PDW should be interpreted as a biomarker reflecting platelet heterogeneity within a thromboinflammatory context, without the ability to distinguish between acute and chronic components.

Background: Nutritional impairment has been associated with adverse outcomes in acute coronary syndrome (ACS), yet its relationship with the no-reflow phenomenon remains incompletely understood. We aimed to compare the performance of the Hemoglobin–Albumin–Lymphocyte–Platelet (HALP), Prognostic Nutritional Index (PNI), and Controlling Nutritional Status (CONUT) scores for no-reflow assessment in patients with ACS. Methods: This prospective single-centre study included 279 consecutive patients with ACS undergoing percutaneous coronary intervention. HALP, PNI, and CONUT scores were calculated from admission laboratory parameters. No-reflow was defined as post-procedural TIMI flow grade ≤ 2 in the absence of mechanical obstruction, with myocardial blush grade used in equivocal cases. Hierarchical logistic regression, receiver operating characteristic (ROC) analysis, net reclassification improvement (NRI), integrated discrimination improvement (IDI), decision curve analysis, and bootstrap validation were performed. Results: No-reflow occurred in 46 patients (16.5%). All three nutritional indices were significantly associated with no-reflow (all p < 0.001). In multivariable analysis, only the CONUT score remained independently associated with no-reflow (OR 1.728, 95% CI 1.226–2.435, p = 0.002). The addition of nutritional indices to the clinical model improved discrimination, increasing the area under the curve from 0.649 to 0.693 for HALP, 0.733 for PNI, and 0.770 for CONUT. CONUT provided the largest likelihood-ratio improvement (χ² = 25.98, p < 0.001), NRI (0.757, p < 0.001), and IDI (0.104, p < 0.001). Pairwise DeLong comparisons showed no statistically significant differences among the nutritional models. Internal validation of the CONUT model demonstrated good discrimination and calibration (bootstrap-corrected AUC 0.754). Conclusions: Among the evaluated nutritional indices, CONUT showed the largest incremental improvement in model performance; however, statistically significant superiority over HALP and PNI was not demonstrated. These findings should be considered as exploratory and require confirmation in larger multicentre studies.

Background/Objectives: The triglyceride–glucose (TyG) index, a surrogate marker associated with insulin resistance, has been linked to both blood pressure elevation and circadian blood pressure dysregulation; however, its relationship with ambulatory blood pressure (BP) phenotypes across the full spectrum of contemporary ambulatory BP categories remains incompletely characterised. This study investigated the association of the TyG index with ambulatory BP categories and circadian BP phenotypes in untreated adults undergoing ambulatory blood pressure monitoring (ABPM). Methods: This retrospective cross-sectional study included 723 consecutive adults with no current or previous exposure to antihypertensive medication (treatment-naïve status refers exclusively to antihypertensive pharmacotherapy) who underwent 24 h ABPM and same-day laboratory assessment at a tertiary referral centre. Participants were classified according to the 2024 European Society of Cardiology ambulatory BP thresholds into non-elevated BP (n = 199), elevated BP (n = 243), or hypertension (n = 281) groups. Circadian BP phenotypes were categorised as extreme-dippers, dippers, non-dippers, and reverse-dippers. Associations between the TyG index and ambulatory BP categories were evaluated using multivariable proportional-odds ordinal logistic regression. The joint effect of BP category and circadian phenotype was examined by adding a TyG index × circadian phenotype interaction term to the ordinal model, and circadian phenotypes were characterised using multinomial logistic regression. Results: The TyG index increased progressively across ambulatory BP categories (8.8 ± 0.5, 9.1 ± 0.5, and 9.2 ± 0.6; p-trend < 0.001). After adjustment for age, sex, HbA1c, estimated glomerular filtration rate, and body mass index, each one-standard-deviation increase in the TyG index was associated with higher ambulatory BP category (OR 1.57, 95% CI 1.34–1.83; p < 0.001). The Brant test provided no evidence against the proportional-odds assumption (p = 0.379). In an exploratory analysis, the TyG–BP category association differed across circadian phenotypes (TyG × phenotype interaction, likelihood-ratio χ² = 8.26, df = 3, p = 0.041). In multinomial analysis, a higher TyG index was associated with the reverse-dipper (OR 2.90 per SD, 95% CI 2.06–4.08) and extreme-dipper (OR 2.77, 95% CI 1.87–4.10) phenotypes relative to the results for the dippers (both p < 0.001), but not with non-dipping (OR 1.02, 95% CI 0.84–1.24; p = 0.86) after multivariable adjustment. Conclusions: Among untreated adults undergoing ABPM, higher TyG index values were associated with progressively higher ambulatory BP categories and with reverse- or extreme-dipper circadian BP phenotypes after multivariable adjustment. Because insulin resistance was not measured directly, these results describe an association between the TyG index, a surrogate marker, and ambulatory BP phenotypes; they should be interpreted as hypothesis-generating because of the retrospective cross-sectional design. Prospective studies are warranted to determine their temporal and clinical significance.