Background and Objectives: Effective myocardial protection is essential for successful cardiac surgery outcomes, especially in complex and prolonged procedures. To this end, Del Nido (DN) and histidine-tryptophan-ketoglutarate (HTK) cardioplegia solutions are widely used; however, their comparative efficacy in adult surgeries with prolonged aortic cross-clamp (ACC) times remains unclear. This study aimed to compare the efficacy and safety of DN and HTK for myocardial protection during prolonged ACC times in adult cardiac surgery and to define clinically relevant thresholds. Materials and Methods: This retrospective study included a total of 320 adult patients who underwent cardiac surgery under cardiopulmonary bypass (CPB) with an aortic cross-clamp time ≥ 90 min. Data were collected from the medical records of elective adult cardiac surgery cases performed at a single center between 2019 and 2025. Patients were categorized into two groups based on the type of cardioplegia received: Del Nido (n = 160) and HTK (n = 160). The groups were compared using 1:1 propensity score matching. Clinical and biochemical outcomes—including troponin I (TnI), CK-MB, lactate levels, incidence of low cardiac output syndrome (LCOS), and need for mechanical circulatory support—were analyzed between the two cardioplegia groups. Subgroup analyses were performed according to ACC duration (90–120, 120–150, 150–180 and >180 min). The predictive threshold of ACC duration for each complication was determined by ROC analysis, followed by the analysis of independent predictors of each endpoint by multivariate logistic regression. Results: Intraoperative cardioplegia volume and transfusion requirements were lower in the DN group (p < 0.05). HTK was associated with lower TnI levels and less intra-aortic balloon pump (IABP) requirement at ACC times exceeding 180 min. Markers of myocardial injury were lower in patients with an ACC duration of 120–150 min in favor of HTK. The propensity for ventricular fibrillation after ACC was significantly lower in the DN group. Significantly lower postoperative sodium levels were observed in the HTK group. Prolonged ACC duration was an independent risk factor for LCOS (odds ratio [OR]: 1.023, p < 0.001), VIS > 15 (OR, 1.015; p < 0.001), IABP requirement (OR: 1.020, p = 0.002), and early mortality (OR: 1.016, p = 0.048). Postoperative ejection fraction (EF), troponin I, and CK-MB levels were associated with the development of LCOS and a VIS > 15. Furthermore, according to ROC analysis, HTK cardioplegia was able to tolerate ACC for up to a longer duration in terms of certain complications, suggesting a higher physiological tolerance to ischemia. Conclusions: ACC duration is a strong predictor of major adverse outcomes in adult cardiac surgeries. Although DN cardioplegia is effective and economically advantageous for shorter procedures, HTK may provide superior myocardial protection in operations with long ACC duration. This study supports the need to individualize cardioplegia choice according to ACC duration. Further prospective studies are needed to establish standard dosing protocols and to optimize cardioplegia selection according to surgical duration and complexity.

Analyzing the local pericardial fluid (PF) surrounding the heart can provide insights into the function of myocardial and pericardial epithelial cells. Kynurenine (KYN) metabolites have been associated with endothelial dysfunction and the progression of atherosclerosis. This study investigated the relationship between KYN pathway metabolites in serum and PF and the severity of coronary atherosclerosis, as assessed by the Syntax Score (SS). The study involved 101 patients (mean age: 60 years). Of the participants, 17% were female. KYN and its metabolite levels were measured using API SCIEX 3200 LC-MS/MS methods. Statistical analysis was performed using IBM SPSS 25.0. The mean serum levels of tryptophan (TRP), 3-hydroxykynurenine (3-HK), and 3-hydroxyanthranilic acid were significantly higher (p < 0.01) when compared to the mean PF levels. In the SS-low group, PF IDO activity was significantly higher than serum IDO activity (p = 0.040). In the SS-high group, PF IDO activity was significantly higher than serum IDO activity (p = 0.002). The mean 3-HK measurements showed significant differences between the SS groups (p < 0.05). In this study, higher IDO enzyme activity in the PF compared to systemic circulation suggests the presence of inflammatory activity in the pericardial endothelial cells. This research aimed to uncover the role of amino acid metabolism, which is poorly understood in atherosclerosis. Specifically, 3-HK, a metabolite from the KYN pathway, may contribute to the development of atherosclerosis. These findings indicate that localized kynurenine pathway activation in the PF may contribute to coronary atherosclerosis, highlighting its potential as a biomarker or therapeutic target.

Objective: This study aimed to compare thromboangiitis obliterans (TAO) and diabetic peripheral vascular disease (DPVD), the two major causes of distal limb ischemia, within a single analytical framework. The comparison was not limited to practical biomarkers that could support differential diagnosis but was based on multidimensional parameters that determine the clinical spectrum and prognosis. The two cohorts were systematically evaluated in terms of demographics and comorbidity burden, clinical presentation and limb involvement pattern, ulcer prevalence and localization, real-life treatment strategies (medical, endovascular, and surgical), and hard clinical endpoints (major/minor amputation, hospitalization, and all-cause mortality). DPVD was phenotyped according to the lesion level as isolated distal, isolated proximal, or multilevel. Within this framework, the isolated distal diabetic peripheral vascular disease (d-DPVD) subgroup was analyzed to determine how it differs from TAO in terms of clinical course, treatment patterns, and outcomes, despite the distal anatomical similarity. Methods: In this single-center retrospective cohort study, conducted between June 2019 and June 2025, 120 non-diabetic patients who met the angiographic TAO criteria were compared with 395 patients with DPVD with infrapopliteal/pedal atherosclerotic involvement. Clinical characteristics, ulcer topography, treatment strategies, and outcomes were recorded. The discriminatory value of the blood count and lipid-based inflammatory/atherogenic indices were evaluated using logistic regression and receiver operating characteristic (ROC) curve analyses. Additionally, a separate subgroup analysis was performed for the d-DPVD subgroup, which was considered the closest to the TAO phenotype in this study design. Results: Patients with DPVD were significantly older than those with TAO (61.1 ± 12.1 vs. 39.7 ± 7.9 years; p < 0.001), and male predominance was more pronounced in the TAO group (94.2% vs. 84.8%). Compared with TAO, DPVD was associated with a higher cardiometabolic comorbidity burden and increased inflammatory and atherogenic indices. Although the overall ulcer prevalence was comparable, DPVD more frequently presented with plantar or proximal ulcers confined to a single extremity, whereas TAO was characterized by bilateral or multi-extremity involvement and distal acral ulceration. Antiplatelet and statin therapy, revascularization, and rates of major amputation, all-cause mortality, and hospitalization were higher in patients with DPVD (all p < 0.05). On multivariate analysis, age, cumulative smoking exposure, SIRI, and CRI-I independently distinguished DPVD from TAO (all p < 0.05). In the isolated distal DPVD subgroup, despite similar distal anatomy, inflammatory/atherogenic burden, and overall clinical risk remained adverse. Conclusions: TAO and DPVD are two distinct phenotypes with different pathobiologies and prognoses, despite similar distal ischemia presentations. Simple inflammatory and atherogenic composite indices, evaluated in conjunction with clinical/ulcer patterns, may support the differential diagnosis and risk stratification of patients with peripheral arterial disease (PAD). However, prospective multicenter validation of these findings is required to confirm the results.

Aim: Despite advances in diagnostic strategies, easily accessible biomarkers that can reliably predict pulmonary embolism (PE) in patients with deep vein thrombosis (DVT) are lacking. Recently, systemic inflammatory indices, such as the systemic immune-inflammation index (SII), systemic inflammatory response index (SIRI), and aggregate index of systemic inflammation (AISI), have been investigated as potential prognostic tools. This study aimed to evaluate the predictive value and clinical applicability of these markers in identifying PE in patients with lower extremity DVT.Material and Methods: A retrospective propensity score–matched cohort study was conducted in patients diagnosed with acute proximal lower extremity DVT. Two groups were compared: patients with isolated DVT and those with concurrent DVT and PE were compared. Propensity score matching yielded 290 patients in each group. Novel systemic inflammatory indices derived from hematological parameters (SII, SIRI, and AISI) were evaluated together with neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and traditional biomarkers (C-reactive protein (CRP) and D-dimer). Comparative analyses, logistic regression, and receiver operating characteristic (ROC) curve assessments were performed.Results: Inflammatory indices (NLR, PLR, SII, and SIRI) and conventional biomarkers (CRP and D-dimer) were higher in the DVT and PE group compared to the isolated DVT group (all p<0.001). Multivariate analysis identified NLR, CRP, and D-dimer as independent predictors of PE. Receiver operating characteristic (ROC) analysis demonstrated the strongest diagnostic accuracy for CRP (AUC 0.811), followed by D-dimer (AUC 0.746) and NLR (AUC 0.735) levels.Conclusion: Easily measurable and low-cost biomarkers, particularly NLR, along with CRP and Ddimer, provide significant predictive value for PE in patients with DVT. These parameters may support early risk stratification and assist in clinical decision-making when advanced imaging is not readily available.

Objective: This study aimed to compare thromboangiitis obliterans (TAO) and diabetic peripheral vascular disease (DPVD), the two major causes of distal limb ischemia, within a single analytical framework. The comparison was not limited to practical biomarkers that could support differential diagnosis; it was based on multidimensional parameters that determine the clinical spectrum and prognosis. The two cohorts were systematically evaluated in terms of demographics and comorbidity burden, clinical presentation and limb involvement pattern, ulcer prevalence and localization, real-life treatment strategies (medical, endovascular, and surgical), and hard clinical endpoints (major/minor amputation, hospitalization, and all-cause mortality). DPVD was phenotyped according to the lesion level as isolated distal, isolated proximal, or multilevel. Within this framework, the isolated distal diabetic peripheral vascular disease (d-DPVD) subgroup was analyzed to determine how it differs from TAO in terms of clinical course, treatment patterns, and outcomes, despite the distal anatomical similarity. Methods: In this single-center retrospective cohort study, 120 non-diabetic patients who met the angiographic TAO criteria were compared with 395 patients with DPVD with infrapopliteal/pedal atherosclerotic involvement. The clinical characteristics, ulcer topography, treatment strategies, and outcomes were recorded. The discriminatory value of blood count and lipid-based inflammatory/atherogenic indices was evaluated using logistic regression and receiver operating characteristic (ROC) curve analyses. Additionally, a separate subgroup analysis was performed for the d-DPVD subgroup, which was considered the closest to the TAO phenotype in this study. Results: DPVD was characterized by older age, higher cardiometabolic comorbidity burden, and higher inflammatory and atherogenic indices than TAO. While ulcer prevalence was similar, the distribution differed: DPVD predominantly involved plantar/proximal ulcers in a single extremity, whereas TAO more frequently involved bilateral/multiple extremities and distal acral ulcers. Antiplatelet/statin use and revascularization were more common in patients with DPVD, and major amputation, all-cause mortality, and hospitalization rates were also higher. In multivariate analyses, age, cumulative smoking exposure, SIRI, and CRI-I distinguished DPVD from TAO independently. In the d-DPVD (isolated distal) subgroup, despite a similar distal anatomical distribution, the inflammatory/atherogenic burden and clinical risk were more unfavorable. Conclusion: TAO and DPVD are two distinct phenotypes with different pathobiologies and prognoses, despite similar distal ischemia presentations. Simple inflammatory and atherogenic composite indices, evaluated in conjunction with clinical/ulcer patterns, may support differential diagnosis and risk stratification in patients with PAD. However, prospective multicenter validation of these findings is required to confirm our results.