Aims: Recent studies hypothesized a role of gut microbiota favoring atherosclerosis via an increased oxidative stress, but data in peripheral artery disease (PAD) have not been provided yet. The aim of this study was to assess serum lipopolysaccharide (LPS) as well as oxidative stress in PAD patients and controls (CT). Furthermore, we wanted to analyze the relationship between LPS and the severity of atherosclerosis in the lower limb arteries. Results: Eighty consecutive subjects, including 40 PAD patients and 40 CT were recruited. A cross-sectional study was performed to compare serum LPS, soluble Nox2-derived peptide (sNox2-dp), hydrogen peroxide (H₂O₂), H₂O₂ breakdown activity (HBA) and ankle brachial index (ABI) in these two groups. Serum zonulin was used to assess gut permeability. Compared with CT, PAD patients had significant higher values of LPS, zonulin, sNox2-dp, and H₂O₂; conversely ABI and HBA were significantly lower in PAD patients. LPS serum levels were associated with atherosclerotic burden as depicted by the inverse correlation with ABI. LPS was also associated with oxidative stress as shown by its direct correlation with markers of oxidative stress such as sNox2-dp, serum H₂O₂, and HBA. Finally, we found a significant correlation between LPS and zonulin. A multiple linear regression analysis showed that LPS was significantly associated only with ABI. Innovation and Conclusion: These findings suggest that LPS is elevated in PAD patients with a close association with the atherosclerotic burden and oxidative stress. The correlation between LPS and zonulin suggests that changes in gut permeability could be a potential trigger of LPS translocation in the peripheral circulation.

Background and aims: Offspring of patients with early myocardial infarction are at higher cardiovascular risk, but the underlying physio-pathological mechanism is unclear. NADPH oxidase-type 2 (NOX-2) plays a pivotal role as mediator of oxidative stress and could be involved in activating platelets in these patients. Furthermore, altered intestinal permeability and serum lipopolysaccharide (LPS) could be a trigger to promote NOX-2 activation and platelet aggregation. This study aims to evaluate the behavior of low grade endotoxemia, oxidative stress and platelet activation in offspring of patients with early myocardial infarction. Methods: We enrolled, in a cross-sectional study, 46 offspring of patients with early myocardial infarction and 86 healthy subjects (HS). LPS levels and gut permeability (assessed by zonulin), oxidative stress (assessed by serum NOX-2-derived peptide (sNOX2-dp) release, hydrogen peroxide (H₂O₂) production and isoprostanes), serum nitric oxide (NO) bioavailability and platelet activation (by serum thromboxane B2 (TXB2) and soluble P-Selectin (sP-Selectin)) were analyzed. Results: Compared to HS, offspring of patients with early myocardial infarction had higher values of LPS, zonulin, serum isoprostanes, sNOX2-dp H₂O₂, TXB2, p-selectin and lower NO bioavailability. Logistic regression analysis showed that the variables associated with offspring of patients with early myocardial infarction were LPS, TXB2 and isoprostanes. The multiple linear regression analysis confirmed that serum NOX-2, isoprostanes, p-selectin and H₂O₂ levels were significantly associated to LPS. Furthermore, serum LPS, isoprostanes and TXB2 levels were significantly associated with sNOX-2-dp. Conclusions: Offspring of patients with early myocardial infarction have a low grade endotoxemia that could generate oxidative stress and platelet activation increasing their cardiovascular risk. Future studies are needed to understand the role of dysbiosis in this population.

Background: Few data are available on the outcomes of patients with venous thromboembolism (VTE) on long-term reduced dose of direct oral anticoagulants (DOACs). We evaluated the effectiveness and safety of reduced dose of DOACs for the extended treatment of VTE. Methods: In this monocenter, ambispective cohort study, 140 patients receiving a reduced dose of DOACs for VTE were included. The primary outcomes were recurrent VTE, major bleeding and clinically relevant non-major bleeding. The secondary outcomes were arterial events and minor bleedings. The incidence of the primary outcomes was calculated. The rate for secondary outcomes was descriptively reported. Results: The mean age of the overall cohort was 72 years. Half of the patients were female, 51.4% had a persistent risk factor, 40.0% an unprovoked VTE, and 8.6% a minor transient risk factor. Most patients had lower extremity deep vein thrombosis with or without pulmonary embolism (55.0%) and received apixaban (73.6%) or rivaroxaban (14.3%) for a mean duration of 2.7 years. Regarding the primary outcomes, there was one recurrent VTE (0.7%), four major bleedings (2.9%) and two clinically relevant non-major bleedings (1.4%). Regarding the secondary outcomes, there were four acute ischemic strokes (2.9%) and two minor bleedings (1.4%). Conclusions: Reduced dose of DOACs was associated with a low rate of recurrent VTE and an acceptably low rate of bleeding complications. The rate of arterial events during follow-up suggests the need for an assessment of cardiovascular risk factors in this study population.

Background: Valvular heart disease remains a major global health issue, with mechanical prosthetic heart valves (MPHVs) widely used in surgical valve replacement. However, these devices carry a risk of thrombosis, particularly in the mitral position. Several mechanisms may be involved in this risk, but the role of oxidative stress (OxS) remains unclear. Our aim was to assess the relationship between OxS impairment and platelet activation. Methods: We analyzed data from a pilot, observational, monocentric study conducted at our anticoagulation clinic at Sapienza University of Rome, involving adult patients with MPHVs (aortic or mitral) on vitamin K antagonist therapy, enrolled between June and September 2024. Clinical data and blood samples were collected to evaluate markers of NOX2-mediated OxS (sNOX2-dp, H₂O₂) and platelet activation (sCD40L) using ELISA-based assays. Results: Our cohort included 30 patients with mitral MPHVs and 30 patients with aortic MPHVs (46.7% males, 53.3% females). Serum sNOX2-dp and H₂O₂ were significantly higher in patients with mitral MPHVs (28.69 [25.08–33.18] vs. 24.27 [17.30–26.41] pg/mL, p = 0.001, and 22.94 [15.79–27.33] vs. 16.73 [12.50–20.87] µM, p = 0.013, respectively) compared with aortic MPHV patients. sCD40L was significantly elevated in mitral versus aortic MPHVs (5.61 [3.69–6.89] vs. 3.65 [2.14–5.54] ng/mL, p = 0.009). Spearman’s correlation analysis showed a significant correlation between sNOX2-dp levels and sCD40L in both groups (mitral MPHVs: r_s = 0.521, p = 0.003; aortic MPHVs: r_s = 0.443, p = 0.014). Conclusions: Mitral MPHVs are associated with heightened OxS and platelet activation compared to aortic MPHVs. These findings may help explain the higher thrombotic risk observed with mitral valves and support differential management strategies.

Aging is associated with enhanced platelet activation that may contribute to the occurrence of cardiovascular events. However, the mechanism linking aging with platelet activation is not fully understood. The objective of this study is to investigate the relationship between aging, platelet Cox-1 expression, and thromboxane (Tx) B2 production in patients with atrial fibrillation. Serum Cox-1 and TxB2 were measured in 134 patients with atrial fibrillation. Correlations were assessed between age, Cox-1, and TxB2. A robust mediation analysis evaluated whether Cox-1 mediates the association between age and TxB2. In vitro experiments were performed in 20 patients to evaluate the effect of aspirin on platelet TxB2 production and to quantify platelet Cox-1 expression across age groups (i.e., < or ≥65 years). Serum Cox-1 and TxB2 progressively increased by decades of age. A positive and significant correlation was found between age and Cox-1 (R = 0.42, p-values < 0.01), age and TxB2 values (R = 0.44, p-value < 0.01), and Cox-1 and TxB2 (R = 0.5, p-value < 0.01). Cox-1 partially and significantly mediated the effect of age on TxB2 (β = 5.23, 95% confidence interval [2.33–8.63]) for the effect of age on TxB2. In vitro analysis showed a reduced inhibitory effect of aspirin on platelet TxB2 production in old compared to young subjects (IC₅₀ 97 μM and 49 μM in ≥ and <65 years, respectively) that was paralleled by Cox-1 overexpression in patients ≥65 years. Platelet Cox-1 expression was inversely related with aspirin inhibitory effects (R = −0.640, p-value < 0.01). Aging is associated with a concomitant increase in Cox-1 concentration and TxB2 production and an impaired ability of aspirin to inhibit Cox-1.

Background: atrial fibrillation (AF) patients with obesity and high thromboembolic risk need oral anticoagulant therapy. Limited data are available on direct oral anticoagulants (DOACs) in this population, and a point-of-care method has been validated to support rapid clinical decisions and to identify on-off plasma concentration thresholds. Methods: This is a monocentric, cross-sectional diagnostic accuracy study on obese AF outpatients referred to Policlinico Umberto I of Rome. Urinary Dipsticks were assessed with separate pads for factor Xa (FXA-i) and thrombin inhibitor (THR-i) and compared to the reference standard of trough and peak plasma concentrations with chromogenic assays/dTT and prespecified plasma thresholds for each DOAC. Study endpoints were the sensitivity, specificity, positive and negative predictive values (PPV and NPV) of DOACs Dipstick compared to plasma concentrations. Sub-analyses according to obesity severity and type of DOAC were performed. Results: 320 paired plasma and urine samples were available from 160 enrolled patients (mean age 73.2 ± 9.1 years). Compared to trough plasma concentrations, DOACs Dipstick showed a sensitivity of 99.24% (mean, 95% confidence interval, CI 95.82–99.98), specificity of 6.89% (0.85–22.76), PPV 82.80% (81.32–84.18), NPV 66.67% (15.79–95.52). On the other hand, compared to peak plasma concentrations, DOACs Dipstick showed a sensitivity of 97.8% (93.7–99.5), specificity of 0% (0.0–15.4), and PPV of 85.9% (85.6–86.2). Urinary Dipstick showed a sensitivity of 99.10% (95.4–100.0), specificity of 4.70% (0.60–16.20) and a PPV and NPV of 74.50% (73.2–75.8) and 66.70 (15.7–95.6), compared to plasma thresholds > 30 ng/mL of FXA-I and THR-I. Sub-analyses showed similar results between FXA-i and THR-i. Conclusions: The urine point-of-care has high sensitivity, acceptable PPV, but low specificity and NPV in AF obese patients and may be useful only in selected clinical scenarios.